Radio problems again
 

I'll try to make this as clear as possible. I HAD a pristine 93 190E with 50K miles. It was totalled by a sideswipe from a semi. I purchased a nice body 92 190E and swapped the engine/tranny and all is well. Now I'm working on the creature comforts. The 92 had an aftermarket radio tuner (Kenwood) head installed which did not work when I bought it - the faceplate was missing. I wanted to keep it OEM, so I pulled the console, restored the wiring back to original including the original console fader, and installed the Alpine head from my 93, which was working fine previously. I know the wiring is correct, have done all the continuity checks, but still have two problems. 1: no audio - right side, and 2: power antenna does not work at all. Since the head was fine in my 93 (everything worked correctly, and I'm positive I have the wiring back to OEM with no errors, the only difference I haven't checked yet is the amp in the trunk. I thought the amp was for the door woofers only, and have not swapped this out yet. Can the amp cause my two problems?? Oh, and I have also swapped out the rear and dash speakers from the 93 too, which were all working as they should, so I doubt if it's the speakers. Am I missing something? Gilly, you have been spot on in the past with my questions, but this one has me stumped. Thanks; Don

For the antenna, check your connections at the switch and at the antenna itself. If all looks good, it might just be a bad switch or the antenna motor went. My antenna motor has went on me before. Also, check your fuses.

For the speakers, the amp only powers the door speakers. Did you check the fader switch to see if its slightly disconnected?

I would definately look into the fader switch most aftermarket installs in benzes bypass the fader. I would check to see if this is the case, it could also be that new speaker wires were run tot he speakers.

Sounds like quite a project you have endured to get back to what you had.

For the antenna, the easy way to test would be to make sure you have the right wire, make sure if the car has a dash mounted antenna switch that it is set to the up or auto position, and if that is not the case, check the antenna itself.

If the antenna is at fault it is most likely the relay unit for the antenna. or possibly the motor, and in some cases the mast is broken or the gears inside broke.

Alon

Thanks all for the replies. Yes, it's been a lot of work, but I really like the 190E and since I only had 50K miles on the old one I figured it was worth saving.

It's not the fader; I even replaced it with another - same symptoms. If I force the BALANCE all the way to the right and crank the volumn all the way up, I can I hear weak audio from the right side. Sounds like the head unit has gone bad - again. Was working fine before the wreck before though.

I have no antenna switch on the dash on either vehicle. On my 93 the antenna went all the way up when I turned the Alpine radio on and retracted when I shut it off. Probably the antenna motor has gone bad; I can take the old one off. Much of a job? Haven't done this yet so don't know where to start. Where's the relay, and is voltage or a ground applied to the coil to move the antenna? Sorry, don't have a schematic. Don

antenna is simple. rmeove left side of trunk interioe panel. undo not on top of antenna. undo bolt inside trunk on bottom and unplug the wiring harness and pull the sucker out.

Have you tried a different radio to see if that is the problem?

Is it possible that your 93 had 2 amplifiers not one?

Alon

Antenna problem solved but I feel like a jerk. Went to the garage where my 93 is with intentions of pulling the antenna off, looked at it, and it was slightly different. Some %&$*# had installed an aftermarket non-power antenna on the 92. Good reason why it didn't work. Thanks for the advice on removing the antenna - next weekend job - I'm tired.

Only one amp on the 93 in the usual place. Did any 93's have two amps?? I think it's the head unit. BTW, my 93 is in super shape, except for the drivers door and the roof is caved in. Gray exterior and interior. Lots of good parts. Email if you need something. Guys on this forum are the best. Don

Don
If this has the right/left output on the back of the radio, you can swap them side to side to see if the problem switches to the other side (bad channel) or remains on the same side (speaker, amp, fader, etc).
MB actually offers a manual antenna for these and several others, for some owners it's a good compromise. Nice fit and finish.

Gilly

Hi Gilly. Tried swapping the back of the tuner speaker outputs; the no right output problem remained. Did swap the right speakers, both front and rear. Noticed you mentioned the amp as a psooible culprit - this is the only component I have not swapped out. But I thought the amp was just for the door sub speakers. Could the amp be killing the right side output? If so, no problem changing out since I have a readily available parts vehicle which was operating correctly before the accident.

Don
Well at least I'll admit if I'm not sure, and I'm not. The car might have the system called "Active Bass", then I'd agree it's a long shot it's the amp. It may not be this system though. I'd agree with the previous poster, be real careful about the fader switch, try to really inspect the harness between the radio and switch, may be butchered up at some point under the front of the console. I'm about to leave for work, I'd be willing to look at my diagrams tonight if you have the time. Another quick thought is if it has door speakers, maybe damaged wiring in the rubber conduit that leads the wires all in to the door.
Gilly

Radio/antenna Problems (Continued)
 

Still no right side audio; am looking for another CM2191 head unit even though it was working fine in the old benz. Continuity checks are fine, seems like everything I swap from my known working OEM 93 system (active bass, 93 to a 92 - sameo) doesn't work. Which brings up another problem.

Swapped out my known good power antenna - no up or down. The antenna I removed was an aftermarket non-power unit, but luckily the previous fool (I feel like the current fool) did not butcher the wiring, everything was intact. Swapped out and hooked everything back up to the OEM power antenna as normal. I know my blue wire in the head unit is connected, so what am I looking for on the OEM antenna blue wire when the radio is turned on to raise the antenna? GND or 12V? I see neither. It's parked in the DOWN position. I swear, swapping the engine and tranny was easier than fixing the electronics. Relay??

Checked all fuses and installed the correct amperage for all positions. They were not quite correct according to the cover, but only found one blown fuse, the aux fan fuse. Swapped all relays IN the fuse box, no help. Thought I might stumble across the antenna relay by doing this, but I'm not sure where it is. Where is it? This could be the problem?

Electrical problems remaining:

1. No right side audio out.
2. Antenna parked down.
3. One power window does not work, drivers side rear.
4. No console interior lights (Vent/AC buttons, etc). Dash cluster lights are fine, cigar lighter works also.

Anything common here? Many thanks for your help guys. Can't stand it when stuff is not working as it should......

Don

I may take a few posts to answer all this as I search my disc for individual problems.
On the sound system, it appears the amp would only cause a problem with the bass speakers in the doors, not the normal dash and hatshelf speakers, they run right out of the speaker. Can you use a substitute speaker to verify output from the radio? i have some tiny ones I use for checking channels, with MB radio connectors attached, may have a spare one. I am still rather suspicious of the fader or connections at the fader.
EDIT: To clarify it looks like the trunk amps ONLY output is to the door speaker, although inputs tee off from the radio outputs to each side - and +. Unless the amp is shorting out the channel. Try disconnecting the amp from the sound system as a test.

Gilly

Hey Gilly, thanks for the prompt reply. I have swapped all speakers at their locations (dash and rear deck) except the door subs, symptoms remain consistent. Have not tried plugging directly into the head unit, but my wiring continuity is fine, and have even changed out the fader pot. But I can do this, good idea. Antenna makes no sense either. This is driving me nuts. Time-wise, I'm nearing the time it took me to change out the motor and tranny. AAAAAAAAAARGH.......

Antenna checks:
red wire from fuse 13, hot at all times
blue wire from radio, hot when radio is on.
brown is a ground wire, check for good ground.

May also be a modification required if antenna is a newer replacement, not sure what is neccesary to modify the antenna anymore. Think it has something to do possibly with the antenna switch on the dash, antenna was changed so it's either all the way or down, no more length "trimming" possible. If your car doesn't have a seperate antenna switch on the dash, I'd say disregard the possiblity this is the problem.
EDIT: NO relay, all handled in the motor.
Gilly

On the window, especially the 201's are noted for wiring cracking in the conduit from the B post to the door itself. 1st step is to R&R the door panel and see if power is getting to the motor or not, DON'T touch anything, just TEST for power command to the motor. If no volts, THEN try gently pulling on the wires where they exit the conduit to see if one is obviously broken. If so, then I hope you're good with a soldering gun. I recommend putting in about a 12" patch through the conduit area as the wiring is already brittle, and making a repair that just ends up in the same bend point won't last. You want nice supple wiring inside the bend area again. Replace as many of them as you want, inspect for insulation cracking. You could of course also have a bad switch, power supply is OK if the right front works, as it's fused together (right front with left rear and vice-versa), a bad switch in the door will also make window quit fron the front switch. If power is getting through then of course it's the window motor.
OH and if no voltage and also apparent broken wire, you could still have a cracked wire but the insulation is still somewhat intact, may have to explore a bit more, loosen up conduit to inspect wire, you of course don't want to tug hard on the wiring trying to find a broken one ("careful what you wish for" policy I guess you'd say, as in "THERE, NOW you have a broken wire, dumass!" Fix the wire you just ruined, then you're back to step 1 trying to diagnose the problem. FUN let me tell ya. Does this sound like the voice of experience or what?).

Gilly

Illumination, I was kind of concentrating on a connector block called X5. Has power feed to it from the rheostat in the cluster and distributes variable power to these lights. Need a little more info on what does/doesn't work. You're saying nothing in the center console, such as the window switches and mirror switch, what about ash tray light, radio, climate control buttons, and any other switches near the radio and climate control (hazard flasher illumination, any other rocker switches?). I understand the lights in the cluster itself work, these don't tee off X5. Don't ask me where X5 is yet. I think it's behind the dash though attached to a crossmember, doesn't matter right now. OH, what about the switch for the sunroof and the outside temp indicator is fed off X5 also.
Get back to me on this and I'll see what my guess is.

Gilly

If it were easy, everyone would do it..........

Gilly

I just went through a radio update on the newly axquired 93 190e 2.6. Despite a series of hassles I could not figure out what in the $%# was wrong with getting sound to the right front and left rear.

Answer: Left rear and right front speakers were bad!

I should have trusted my scratch test (9v battery to each speaker)

Sounds great now.

Haasman

Thanks for the research Gilly. I'll reply in order:

1. Antenna: red wire from fuse 13, hot at all times (fuse 13 circuit is good; all other devices powered through this fuse work fine).
blue wire from radio, hot when radio is on. (this is never hot at the antenna. Will check output fm. radio, then at antenna. Suspect I may have an open in the harness, possibly affecting the radio too if it's on the same harness run).
brown is a ground wire, check for good ground. (All brown grounds at antenna look good and clean.) Glad to hear there's no relay, it's a wiring problem then. Side note: I have several Jeeps I maintain using factory service manuals; guess it's time to invest in one for the 190E. The Jeep manuals have paid for themselves many times over.

2. Rear driver dor window: Haven't dug into this too much except to replace the console panel switch. Have extra door switches, will try that next. Hopefully I can get by without the brittle wiring probs at the door flex tubing; haven't found any brittle wiring yet yet on this car. But I have extra window motors, switches, etc. It's good to have a complete parts car available. :~)

3. Console interior lighting: Only ash tray light and radio light are working. All rocker lights (climate control, windows, etc.) do not. Rheostat in cluster works for cluster illumination only; not for console, obviously because there are no night lights. While I had the console out working on the radio, I replaced all the console bulbs I saw; no help. Guess I have an open somewhere between the rheostat and the tie point for the cluster switches. Sunroof and outside temp indicator work normally.

Again Gilly many thanks for the help mate. Don

Thanks Hassman, but the first thing I did was to replace the speakers with known good ones - even swapped side-to-side, but no help. Got one whole side out which leads me to believe it's the head unit, even though it worked just fine in the previous 93 190E. &%(*&%$#

On the window, really the BEST first step is normally to pull the door panel and check for power/ground at the motor, that's really the "Y" in the road as far as where to proceed. I say "normally" because if you suspect a bad switch and have another to test with, you could try a switch replacement very quickly. Also try the switch in the door itself to see if that works, and see if the "opposite corner" window works, this actually quickly verifies the fuse is OK. You see these wires getting brittle and breaking just due to the door opening and closing, it's not an indicator that the whole wiring harness is shot, but other doors may follow suit.
On testing the radio output, what you can do is remove one of the front speakers (or if you have some more spares) and I believe these do have the same style round connector as what plugs in to the radio, so you can simply plug a speaker directly in to the radio output to test it. Simple.
On the antenna, sorry I don't have more specific info. I looked back at your posts, I see there is no switch for the antenna. Can you try bench-testing the antenna? That's where I'd go next I guess. Well, unless you are saying you get no signal from the radio. You can simply jump b+ from the red wire over to the blue wire, the stupid antenna doesn't REALLY know where the power is coming from. I don't know if the antenna will go down after you remove b+ though, so don't let the antenna go all the way up, may wreck it if you need to remove the antenna, of course you could remove the mast to do this. I'll see if the repair disc lists antenna diagnosis steps, I know MB does have a good set of books, one of which covers radio diagnosis, that's what you really need.
I'll look at the diagram and see if I see what the lighting problem may be, the more info I have on what doesn't work the better.
Gilly

Seems most everything is getting power from this X6 circuit 58d connector, the stuff that works as well as doesn't work. Maybe a loose screw at this connector (it's the kinds with the screw that holds the eyelets on the ends of the wires, there are supposed to be 2 screws on X6). I'll see if I can get a location, probably behind the cluster, looks like most if not all wires will be gray with a blue stripe. Look for hacked wires too. Grounds for these should be W1, the main ground connector behind the dash, ton's of brown wires, again look for hacked wires, the screw/screws should be tight, or else you'd have loads of other problems. Maybe hacked wires when radio was installed or de-installed? X6 looks like in the instrument cluster hole and to the right down low, hard to describe better than that. W1 I looked at, looks like actually 3 lugs, not 1, so examine all 3 screws for tightness. Won't be able to ID which ones would be for your cluster lights though, so look carefully at all of them. You can ID X6 because of the gray wires w/blue stripe, should be 2 lugs.

Gilly

Thanks Gilly. Spend the day cutting out a rotted battery tray/underbody and replacing it with the one from the 93. This is really the only rust I've found on the car so far. Brainless work I know, but I'm sick of electrical problems for the time being. I did order the W201 service manual CD though. As long as I have a schematic I can usually figure things out. I'm almost postivre all my problems are in the console area. The previous owner hacked and slashed wires in there installing an aftermarket head unit and I probably missed something patching things up. It all points there. Will hit it again when the CD comes in, prolly next weekend. Don

If you want to get an early start, I'd remove the upper console trim, around the radio, and also the shifter plate, and check all the grey with blue stripe wires you see. Maybe you'll find wires cut for the speakers and window too! And the antenna!

Gilly

Will do Gilly. Curses on these hackers and slashers with no plan. Here's another strange one maybe you can explain. Today, while I was rebuilding the battery tray, I swapped out the OVP relay since I had just installed a new one in the wrecked 93, and the old one was slightly acid wretched and corroded. No-brainer, right? Put everything back together, and when I started it up to go pick up my daughters this evening, I got an instant ABS light, and it idled like crap until it warmed up. This relay worked great in my 93, but the 92 didn't like it. Weird. Swapped the old OVP relay back in, and all is well. The old one was OEM Bosch, the new one was an aftermarket KAE unit. Electricals, I love it. Can not understand why the Germans can build the best power plants on earth, but are severely challanged on electronics. Must have caught it from the Brits. :~)

Checked the fuses in the supposed "good" one??
Also compare applications to see if they should be interchangeable.
Gilly

Fuses were okay, interchangibility is for all 2.6L engines (according to the specs). Should have worked.

Electrons Update
 

Gilly;

Been messing with it off and on, mostly off, but it's coming along.

Radio: The radio is working now; it was a combination of problems. I did have one cold solder joint in the rear speaker wiring when I rewired everything back to normal in the console, plus found both rear speakers were bad. The fader also had some dead spots; popped the cover and cleaned it out with contact cleaner. Smooth now. Oh, and the right side rear speaker pod wiring was pinched, effectively grounding out the right rear speaker. Wonder it didn't burn out the right side output power transistors on the head unit. The old CM2191 Alpine unit sounds like new now except the sub-woofers in the front doors. Have the amp from the 93 to swap in, hopefully that's all it is. Hard to tell when they are working anyhow.

Left rear door: Pulled the panel, removed the door switch, applied power directly to the motor, no go. Cable was off the track on top too, prolly that's what took out the motor. I pulled the motor from the wreck, but like a dumbass I took out only the motor by removing the cover and unwinding the cable from the spindle instead of pulling the whole unit (never had done it before), so now I have to go back and pull the regulator and figure out how to get the cables back on the spindle correctly. The boot over the wires has also slipped out of the centre post hole, but the wires look okay and are not grounded anywhere. At least I know where the problem is now. Any "how-to" instructions around for removing/replacing the rear door regulator??

Antenna: Need to pull the console again and check for 12V out on the blue wire when powering up the radio. Nothing at the antenna connector when radio is turned on, so antenna remains parked down. Not good for reception - AAAAARGH.

Vanity Sun Visors: 92 and 93 visors are different, different bulbs, micro switches, etc. BUT the center piece which contains the electronics will interchange from the 92 into the 93 housings. However, it won't work vice-versa because there is no cutout for the micro switch arm on the 92 housing. Used the 92 guts, bigger brighter bulbs, all is fine.

Electron things left:

a. The switch on the dash does not turn on the rear passenger light, works fine when opening either rear door. This normal??
b. Still no console lighting for the climate control rocker switches. Cigar lighter and it's illumination light works. Problem in the console or it's feed I'm sure. Good bulbs/fuses.
c. Swap out gauge cluster. Everything's working, except the trip meter and the temp LED has some UV damage on the readout, but it's readable and working. Besides, the 93 only has 50K miles on the clock!

Thanks for putting up with all this, but it helps me explaining what I'm doing, and later on when I get smarter I hope I can help others. Mechanically it runs as new. Hopefully if my better half doesn't put me to work as usual in the yard, I can knock out these niggling problems. Just bugs me when stuff doesn't work........

Don

Antenna Problems (Continued)
 

I bench tested the antenna as suggested in a previous post and it worked fine. Then I traced the single wire (separate from the 4-wire plug) which supplies the 12V feed when the radio id turned on. It dead-ended in the cell phone transmitter plug tucked up behind the cover. Found an ignition-switched 12V and connected it to the antenna, and the antenna works rises when I turn on the key, and retracts when I turn it off. Worked well for about a month; today it quit working agao\in, but I can still hear the motor running/cycling when I turn on the key. Trouble inside the antenna I suspect?? Stripped gear or something? Thanks; Don

either a broken gear or the cable ont he mast broke. you should be able to hook up that feed wire instead of using +12v on the ignintion hook it up to the antenna lead on the headunit itself. That way it will go up and or down whent he radio is turned on/off.

Alon

I believe your antenna has a belt that drives the gear. If you are so inclined ... take the cover off the antenna motor and see if the belt is broken.

So a search under my name, I posted a link in this section for an excellent source of antenna parts if you need them.

Haasman

Gilly,

Pulled the cluster this weekend and the long wire which is hardwired into the cluster and plugs into a male connector on the firewall was disconnected. Plugged it back it and everything works fine. Also found a broken nylon gear in my Hirschmann euta 6000 antenna. Purchased a gear repair kit, re-assembled, and it too is working. Left rear door problem was the regulator. Out in an aftermarket regulator assembly and it's working well. That about finishes all the little stuff; for now. Thanks for your help, and everyone else on this great forum.

Glad everything is working and you seem to be enjoying fixing up the 190.

Gilly