Fuse Strip ? Glow plug timer ?
 

Here goes. An 85 300SD I recently inherited from my Dad. It has sat for awhile and I am getting reacquainted with this excellent car. As I go through and bring all the services up to date I am gonna have more than a few questions and have been doing searches in the archives of other sites as well.
Here goes my latest ???.
1. My Dad had a new set of Bosch glow plugs in a bag in the trunk along with a
notched metallic strip in a small parts bag.
2. The bag says Fuse strip and has a few different part numbers on it
178 3186 N17 125 3
3. The plugs are Bosch 80006
4. Currently the dash light for the plugs does not light and I do not hear a click
as in from the timer. The car starts immediately though ( I wait 30-40 seconds after the dash lights up anyway though).
5. There is a spot under the hood on the drivers side inner fenderwell that looks like something was mounted there at some point but is no longer there.

So what is this Fuse strip, where does it go, does this car have a timer for the plugs and where is it what does it look like ?
The ARS light in the dash came on while driving this to my home and as I thought all the belts were very loose so I am replacing them. The battery is 2 weeks old. I am hoping that with the belts done the ARS will go out and the dash glow plug light will come on. Any thoughts while I putter with this are appreciated.

There is a strip fuse on the relay, it's probably an 80 amp. Yet your plugs seem to be working, in that case, so would the fuse. Check the glow plugs with an ohm meter. Not hearing a click after 30-40 seconds doesn't fit in tho. It does have a timer, that is the four prong part, the five are for the glow plugs.
Inspect the pad sensor wires on the front wheel hubs, this may be causing the ARS (ABS?) light to stay on. It may be broken or the pads need replacing.

Thanks for the quick response and the photo. Where is this relay located I had read somewhere it is on an inner fender well ? I am going to replace the glow plugs anyway since I have them. Also going to rebuild the injectors and am not certain when the valves were last adjusted. My Dad had some declining health issues and is not too helpful as to when these were done. This car was meticulously maintained until 5-7 years ago and has been garage kept. It was his pride and joy and special gift he bought after retiring from the USMC after
31 years. I may pick your brain from time to time if that is okay. I noticed you live in central VA. Where ? I live in Ashburn near Dulles airport.
Alan

Generally, located on the front of the driver's fenderwell, but you should be able to follow the wiring harness back from the glow plugs to the relay.

First, when you find the relay, there's a wire that goes to the dash light. Apply +12V to pin #3 on the four-pin plug and make sure the light works. It probably does. You may have only a single glow plug out. The relay module has a comparator circuit in it that measures the #1 glow plug against the sum of the rest of the plugs. Check #1 first, and if it isn't right, replace it and see if the light comes on then. If it does then save the rest of the glow plugs for issues further down the road. If it doesn't, replace them all. They're probably due.

Also remove the fuse, inspect it for a crack in the middle (it happens) and re-install it if it looks good. Keep the strip fuse in the glove box just in case.

My regards to your father for his service.

Again , it is always great to get fast responses from the members here. I went back before reading your post and found the relay ( cheated and went to Peachparts site and looked for the relay and used there pics plus the one sent by toomanybnzs and found it. The relay does not appear to be broken however it does appear bent in the middle so I will remove an check ( it might be a small hairline break) also the one plug cap does not appear to be seated fully so I will clean and recheck once I have all the belts back on. As a long time owner of german cars using the bullet fuses I know they can look fine but are corroded where you can not see and thus to not allow proper operation. I will be changing all the fuses out. As for my Dad. He is still kicking but has dimentia with a touch of alzheimers thrown in. He has moments of great clarity at the most unexpected times. On the 4th at my parents home he thanked me for getting his Mercedes squared away for him since he wanted to take a drive and
see some of his friends ( all buried at Arlington National Cemetery)
I will update and add more questions as I proceed thanks again.
Alan

Along the same line. Just below the ABS pump and to the left of the timer relay is a flat preformed mount with a bolt hole on the middle. It shows a slight ring of rust where possibly a washer rubbed. There is nothing mounted there but it sure seems as though something is missing. My Mom had this at a shop that was not specifically one that works on MB's let alone a Diesel. I did not feel comfortable with them but they were polite to Mom so she used them. I am
suspicious. Any thoughts as to what was mounted there. I try to take a photo
here later.
Again thanks
Alan:confused:

I have a similar spot, haven't the foggiest of what was there. I don't have ABS on my 83.

Same location but mine is an actual formed/ bent sheet metal piece that the ABS pump is mounted above and there is a flat vertical surface where something was attached. My daughter has the digital camera at her grandmothers house for a couple of days so I cannot post a photo. It may not be important but I am :confused:very curious about it.
Alan

The Glow Plug Relay Fuse is supposed to have that bent down dished area. That Bend helps keep it from breaking due to expansion and contraction.

The new Strip Fuse is flat. When you instll the new Strip Fuse leave the screws a little loose and use one of your Fingers to apply just enough pressure to slighly bend the Strip Fuse. Hold it there and tighten the Strip Fuse Retaining Fuse.

Just out of the other pic is a bracket of some sort, doesn't seem anything was ever attached on mine.

Took a while to get back to this issue with the car ( had to replace a window regulator) however today I finally put my meter on the plugs and they are all good and the voltage climbs. I did finally hear the GP timer come on it was fairly quiet. I have brand new GP's in the trunk so I am going to install them anyway
the dash light still does not come on. I will take the advice from an earlier reply to this thread and trace it back to the dash and hope it is a wire. Otherwise
how bad is it to remove the dash on this and replace the bulb or can it be reached from below.
Thanks
Alan:)

I finally had a few minutes and started to change out the glow plugs this afternoon. I quickly realized that I had all the tools I needed.........at my parents home. So I started into it anyway and as I removed the first one it did not look bad at all except for a thin coat of black almost crystalline like substance at the tip. I changed it out and promptly dropped the nut for the power lead and down it went. Looked and looked etc. finally sprayed some brake cleaner in the area that it fell and then shot some compressed air as well
( after placing a large SS catch tray under the car and ping there it fell.
I placed the lead on and tightened everything down. by now I saw it was going to take longer than expected without the proper tools so I started putting my tools away. When done I thought I would go ahead and see if it had affected the non functioning dashpod GP timer light. As I turned the key it flashed on and quickly went out. I tried again but no go. I pulled the key and did it again and bang the light came on and promptly went out. Anyway I will change the remaining plugs Monday and see what happens. The GP's get power and the timer gets power and you can hear the relay click and it has a brand new correct battery ( another thread). The only issue is no GP light and having to cycle the GP's 4-5 times when the temp drops below 69 degrees or so. I will update.
Alan

The GP timer needs a working temperature sensor. Have you measured the sensor? It looks a bit like the GP timer/relay thinks the engine is at operating temperature all the time..

If you want to get a longer life out of the new Glow Plugs you should clean the Carbon out of the Glow Plug Holes.
There is a Glow Plug Reamer made for that our you can used one of the other methods from the DIY Section.
DIY Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82

http://www.peachparts.com/Wikka/DoItYourSelf

ES, So the GP timer takes readings from what sources to determine glow time ?
Also how to check the associated sensors ? Does it read from the sensor at the thermostat housing ? Block ? Any help would be appreciated. I am going over to pick up my tools to make this job easier ( I just do not want to pull hard fuel lines at the injectors but is that what everyone else does ?)
Thanks
Alan

I don't know about the sensor, but if your plugs need changing, go ahead and do so.

I have swapped out glow plugs both with the metal fuel lines off and on. Off is much easier, but it can be done either way.

Hey Bob ! How are things going. I was going to PM you with a few questions but have gotten busy getting my 03 Suburban ready for Winter. My wife works at a Hospital in Washington D.C. and also at National aka Reagan National Airport. Both jobs the only excuse for not making it in to work even with bad weather is Death. Anyway as I posted before I got no light at all but I do hear the relay click. I checked before and was getting 11+ volts at each plug while the timer cycled. The light came on for the first time in many years. If you turn the key to the preglow position it comes on and promptly goes off in a split second. I am going to do the other plugs regardless ( what a pain to get to,
those crazy Krauts. First they give the world Lederhosen and then barely accessible recurring maintenance parts) But ES had a good comment earlier.
Where does the GP relay get the information to glow or not and for how long.
It is hard to start in the a.m. when it gets a little cool but is pretty much okay when it is hot out. I know the valves need adjusting ( still have not gotten around to it) and it has gotten slower as well. When it starts in the a.m. there is a large cloud of white smoke ( fuel unburnt ?) and very rough idle so much that i have to feather the pedal to keep it running and then it smooths out some. I also believe I need new injector nozzles( in a few weeks)
Also the mileage is down. I did find fuel weeping from around the banjo bolt on the valve cover side of the IP. It is the clear line that goes from the spin on fuel filter top ( return line ?) I snugged it up and will watch it to see if it stops. Ideas ?
Thanks
Alan

I don't know where the sensor is located on the OM617 engine (despite having one myself..), but I guess there isn't that many on the engine. I guess there is two - one for the temperature gauge in the instrument cluster and one for the glow plug system. Just pull one and see if the dash gauge reacts, maybe? If so, then it's the other one.. ;)

See how the dash light reacts once new plugs are in.

Some smoke at start up is normal.

If the local fuel station uses a winter blend, you may get lower mileage, less energy, more anti-gelling compound.

That leak is in an unusual place. That fuel bypass valve has metal seal rings, or crush washers, so unless disturbed there isn't much of a chance to leak.

If snugging them up doesn't help, replace them.

The timer uses ambient air temp measured internally. At least that's the way it is on the USA versions.

Update
 

Okay it has gotten kinda busy around here on weekends so I have not had a block of time to finish everything but here goes. I replaced 3 of the 5 GP's and will replace the 2 most difficult to reach today. I did leave the fuel lines in place, will not make that mistake again ! Now the interesting part, with these 3 new plugs the car starts on a 32 degree morning with the GP relay cycle albeit somewhat rough but warms up and smooths out at idle quickly. The Inop GP light on the dash has started working but still kinda odd. It glows for about 14 seconds so I still wait to hear the relay click before starting. I am hoping the last 2 GP'S will solve that problem. Second on another thread I noted the issue with the battery being the minimum spec for this car and that I was able to exchange it and pay the difference ( $26.00) to get the Monster large and called for battery for this vehicle. I noticed this a.m. with the cold temp and did not have the car plugged in over night that the engine cranked easily and started up pretty well. Next step is to fix antilock light in dash / ABS inop at the moment. Also do front brakes and rotors and flush system. I believe the constantly on Antilock light is a broken sensor wire. Anyway I need to do a valve check/adjust and that will probable come before anything else. The car seems to be lacking power and I do not believe that the turbo is kicking in. I pulled air cleaner and housing and found 2 things- the air cleaner housing mount is almost brand new and that some one took a shortcut when they did the oil return tube "O" ring replacement, they just shoved another one on and it was not in the correct groove so oil has been coming out of there. The turbo spins easily with my finger and does not wobble seem bound up in any way ( I know this is without oil pressure) I also made sure there were no mice nest's in the air intake and all is clear. I need to see if enough exhaust is getting to the turbine. Heat works perfectly. A whining sound coming from the rear possibly driveshaft support bearing ?
Again sorry to ramble but thanks to all for your help I will update again.

Properly mount the drain tube "O" ring.

The turbo isn't bound up, good. Check the banjo fitting on the intake manifold. If it's clogged up, the ALDA won't get the proper signal and too little fuel will get to the engine.

Change the rear end fluid, this may change the rear end whine.

Good luck and keep us posted.

Toomany MBZ, Yeah today I have to go meet with a lawyer about some issues but am going to try to work on it in the afternoon. There were 2 "O" rings on the piece of the tubing that comes out of the air filter housing bottom but neither one of them was in the proper place and were just pushed up to the bottom of the housing. As I wrote earlier it looks as though that is where the oil was coming from. There was very little oil in the bottom of the filter housing in fact it was barely even wet with any oil. I just get the feeling that a valve adjustment would help the overall performance. Another issue I mentioned before was that when I installed the correct exhaust hangars a thrumming vibration started and you can see that the 2 rear pipes at the bumper are canted quite a bit and I believe that I need to loosen the attachment point for the entire underside exhaust pipes and get it to hang correctly ( on a lift) the original install and zip tie hangars were all done at the same shop so I suspect they did not bother to hang it right so long as it did not leak. Is it correct that the turbo should spool up ( with everything stock) at around 2200-2300 rpm's ?
I am also considering doing the EGR delete mod and the BB in the vac line trick ( did it to my 79 BMW 302i) The question for you Toomany MBZ is this.
When the egr is bypassed/removed does this effect the additional fuel that would be kicked in and necessary for the turbo to be effective ? I am going to do a quick search for a decent vacuum diagram as it relates to the turbo so I can better understand it. Also I might have a exhaust leak or exhaust bypassing the turbo via a dump valve or an over pressure system ?
Sorry for throwing all of this in but while I am finishing the last 2 GP's and am under the hood I may as well. As for the banjo bolt at the rear intk manifold I did clean it out all the way to the switch on the firewall and also disconnected that and cleaned it well. Do you know a good source for an assortment of the appropriate sized and various elbows for the vacuum lines in the engine bay ?
Thanks
Alan

The exhaust should not be canted, much, anyway. If all your hangers are now of the stock variety, something was improperly done, as you mention. The only item not welded to the underside, is located, I'm guessing, near the front, as it's referred to as a "front exhaust pipe suspension", so good luck with that. See if you have the proper muffler too.

That's about right for the turbo to engage, maybe a bit low rpm.

I couldn't remember if you'd cleaned out the banjo fitting and lines, you have, good.

The egr delete will not have an impact on fuel as far as the IP is concerned, you MIGHT get better mileage, that's all.

I would think you can click on the "buy parts" button and find all the rubber connectors you need. They are mostly the same size.

Your muffler looks new . the rear and center resonator on this were replaced and then not driven much. All MBZ OEm , I bought from Tom Hansen before he left Caliber Motors and went to the classic center in Cali. They appear to be good. This car has one of the center units that has two chambers on either side of the car. I am trying to get some lift time tuesday and see what I can see. as i said it could be that when I put the correct hangars on I may have put a little too much a$$ behind my lifting and twisting and loosened a connection that was already incorrectly made. The car just does not seem as powerful as 1.5months ago off the line or when kicked down. The tranny kicks down but I just do not think the turbo is spooling up correctly. Any good diagrams on the various turbo connections and such ? I am about to go outside and install the last 2 GP's and if enough time before I pick up one of my kids I will pull the aircleaner box again and see whats up. Is the wastegate visible from above ( sorry for a simple ?)
Thanks
Alan

If you have access to a boost gauge, hook that up to the line going to the ALDA. 10 to 11 psi was from the factory. If you get significantly less, some detective work is in order.

The waste gate has arrows drawn to it in the first pic and follow the wrap around hose to it in the second.

That muffler is just over three years old.

Double post, sorry.

The glow plug light always goes out before the relay clicks off. Under ideal conditions, it should be on long enough to get the car started. Just one of those things. Be Zen about it. Change the last 2 GPs so all five are new, and keep the two as spares.