Need help with turn signals and more - PeachParts Mercedes-Benz Forum

eatont9999 · #1 01-27-2012, 08:17 PM

Hello all,

I recently purchased a 1983 300SD and I want to get it on the road ASAP. It needs a lot of work but one of the first things that needs to be fixed are the turn signals. All 4 hazard lights work and flash but the turn signals do not. I was able to get the driver side to blink after fiddling with the turn signal switch for a while but the passenger side won't blink at all. The switch lever seems nice and tight but I am thinking it is the cause of my problem. I am looking around for salvage yards that may have a 1981-1991 Benz that I could rob the turn signal switch from and see if that solves my issue. The fuses look good and I swapped around some relays in the fuse box but no luck.

Hopefully I can get to a salvage yard that has a Benz tomorrow and do some pulling.

It also looks like my passenger side reverse light is out (not the bulb, already checked that) glow plugs stopped working (it cranks but all I get is white smoke from the exhaust) but it starts on ether. I will also look at picking up a set of injectors as it has a haze of smoke when idling at temp. I'll look for a spare turbo as well because it could be a shaft seal leak in the turbo causing the smoke. Oil pressure seems low at idle. I get 1-2 idling and 3 if I give her fuel. Probably due for an oil change, too. I al so need a power steering pump since mine is leaking and needs a rebuild.

Thanks for any help or advice.

Yak · #2 01-28-2012, 10:13 AM

Quote:

Originally Posted by eatont9999

Hello all,

I recently purchased a 1983 300SD and I want to get it on the road ASAP. It needs a lot of work but one of the first things that needs to be fixed are the turn signals.

<<<>>>

glow plugs stopped working (it cranks but all I get is white smoke from the exhaust) but it starts on ether. I will also look at picking up a set of injectors as it has a haze of smoke when idling at temp. I'll look for a spare turbo as well because it could be a shaft seal leak in the turbo causing the smoke. Oil pressure seems low at idle. I get 1-2 idling and 3 if I give her fuel. Probably due for an oil change, too. I al so need a power steering pump since mine is leaking and needs a rebuild.

Thanks for any help or advice.

First: break out your separate issues and start different threads for advice.

For example, working turn signals are very nice, and the rest of us out on the road appreciate them when used correctly, and you do need them to pass an inspection in Texas, but starting a car on ether may be a little higher priority to get fixed.

If you don't have a voltmeter or digital multimeter, I'd get one.

Troubleshoot your GP relay. Find the 80A strip fuse and make sure that's okay. Possibly, even in Dallas, check your block heater and see if it'll work and then start with a warm block instead of ether.

A valve adjustment is probably in order.

Oil pressure sounds okay-ish, but the ranges as described are pretty large, so it's hard to say.

With a new-to-you car and symptoms you describe, a compression and leakdown test would probably be in order before you invest the time and money in a new turbo. If the motor isn't good to start with then you may need to shift priorities.

Sign up for EPC startek to have access to their tech resources.

charmalu · #3 01-28-2012, 11:40 AM

http://www.peachparts.com/shopforum/diesel-discussion/85676-ether-use-abuse-*flame-suit-*.html
Forget the earher, use WD-40 if you need something.

Replace the spinon fuel filter. fill it first with ATF, Diesel purge to the top, then screw it on, I mention ATF and DP, because you would be pouring it out of a clean container. (can,bottle) filling to the top will help lessen air into the system. then pump the primer pump a few times, and start the engine. If it stumbles, just hold the peddle down a little till the air is purged out and should smooth out.

Adjust the valves, really makes a difference with the running of these engines. needs to be done every 15K miles.

I wouldn`t worry about the Turbo being a problem. do the small thing first.

As YAK mentioned, check the Glow Plug relay for the strip fuse under the cover. but is an 80 amp. may look ok, but could have a hairline crack. held in with 2 screws.

Diesel Giant has a good how to do it writeup on trouble shooting the GP`s.
Mercedes Diesel Glow Plug Repair

Light bulbs could be burned out bulb, or corrosion in the bulb socket. also pull off the fuse box cover and check all the fuses. they get corrosion and or the brass contacts in the fuse box. the fuses are a cerramic material with an aluminum strip. some replacements are a plastic material with the aluminum strip. they can melt if a fuse get hot. also think the replacement original cerramic ones are now copper.

Nothing wrong with the oil pressure.
when cold and first starting the engine. it will peg at 3 Bars. then after it is warmed up and at an idle, it will hover around 1 to 2 bars. one bar is 15lbs.
reving the engine will peg it. that is normal.
the oil pressure is much higher than the 3 bars indicated on the gauge. twice that in reality.

Charlie

sethza · #4 01-28-2012, 01:03 PM

Dont start the car with ether, unless you need to take somebody to the emergency room or your escaping a tornado or something....

You can hotwire the gplugs in a pinch, but do it BEFORE the fuse. If you leave the glowplugs on too long you risk breaking the end off into the combustion chamber. When my glowplugs aren't working, it's time to pull out the Schwinn. I suggest you protect your investment..

Buy a cheap voltmeter, and see if your getting voltage to the plugs themselves. If you are, you know you have an open in one of your glowplugs or one of the resistors that go between the plugs. If not, your problem resides in the relay or the circuit, or even the fuse. That's a good place to start.

Careful of the resistors. I've "McGriddled" my hand pretty bad on them before.

eatont9999 · #5 01-28-2012, 08:24 PM

I went to the junk yard today and found an 83 300SD and I robbed a few things from it. I got the turn signal switch, PS pump, Injector lines, 4 Autolite glow plugs, electric antenna assembly.

The turn signals work now, so I just need to figure out that reverse light, battery and the glow plugs, then I can get it registered. The plugs worked fine when I bought the car but something happened recently. I'll try to find this fuse everyone talks about. Is it in that box that is on the front driver's side fender? Not the regular fuse box, right?

SD Blue · #6 01-28-2012, 08:43 PM

The fuse is actually a metallic strip inside the glow plug controller. Pop the cover off and it's between a couple of phillips screws.

However, I would suspect glow plug failure. Usually, what you come across is one or two fail and you get a rough stumbling start. Then, the third goes out and forget it. Then you can try to salvage one or two by going through some testing or you can buy an entire set of new ones and be good for 3-4+ yrs.

BTW, most will tell you to scrap the Autolite plugs as they have a short life and high failure rate. For better reliability, go with Bosch. The set I have are still working fine after 5 yrs.

charmalu · #7 01-28-2012, 08:49 PM

If you look in the Diesel giant link I posted, you will see the GP Relay fuse.

The Autolite GP`s are not known for a long life, maybe a 1/2 life.
But they should get you going. Be sure to put 12V to them before putting them in to see if they get bright hot on the ends.

Again look at Dieselgiant link, shows how to do it.

Good score at the JY.

Charlie

eatont9999 · #8 01-28-2012, 08:53 PM

I took another look at the GP relay box and my strip fuse had a hair line crack in it. Now I just need to source a new fuse and temporarily bypass the bad one.

I pushed down lightly on the crack in the fuse and it bent in. Seems like it is made of lead.

Yak · #9 01-28-2012, 09:39 PM

Quote:

Originally Posted by eatont9999

I took another look at the GP relay box and my strip fuse had a hair line crack in it. Now I just need to source a new fuse and temporarily bypass the bad one.

I pushed down lightly on the crack in the fuse and it bent in. Seems like it is made of lead.

They have been soldered. Not my recommendation for a permanent fix, but it'll get you going. You could join in a discussion on the electrical properties of the solder on the fuse and whether it increases or decreases the amperage, or whether it's the width or the length of the fuse that drive the amp limit. Or just solder yours as a tempo fix while you're sourcing some new ones.

eatont9999 · #10 01-28-2012, 10:06 PM

Quote:

Originally Posted by Yak

They have been soldered. Not my recommendation for a permanent fix, but it'll get you going. You could join in a discussion on the electrical properties of the solder on the fuse and whether it increases or decreases the amperage, or whether it's the width or the length of the fuse that drive the amp limit. Or just solder yours as a tempo fix while you're sourcing some new ones.

Well, I can tell you that the fuse is based on resistance. The resistance depends on the type of metal being used. The more resistance, the higher the temperature of the medium the electricity is passing through. Lead has a low melting point, which is probably why Mercedes decided to use it as a fuse metal. The more metal in the fuse, the longer the time is for heat to build up AKA: time before failure at x volts and x amps. Soldering the fuse with a lead and tin solder will not make a difference in the time and amperage before failure because, even though tin has less resistance, the soldered joint is still surrounded by metal with a lower time before failure and will retain its original fuse-type characteristics.

eatont9999 · #11 01-29-2012, 07:10 PM

Status update: I installed new fuel filters and rubber lines. I used 5/16" hose. I also found my reverse light issue to be a bad bulb. The filament had a hairline crack in it that I didn't see the first time. I also picked up an oil filter, some 15W40 and an air filter. I should be able to get it inspected and registered now. Now comes the fun of dealing with the tax office. I probably should put some insurance on it, too.

eatont9999 · #12 01-29-2012, 07:12 PM

Oh, I put a gator clip on the GP strip fuse and it seems to be working fine for now. I ordered 10 spare fuses for the future needs.

Yak · #13 01-29-2012, 07:21 PM

Quote:

Originally Posted by eatont9999

Status update: I installed new fuel filters and rubber lines. I used 5/16" hose. I also found my reverse light issue to be a bad bulb. The filament had a hairline crack in it that I didn't see the first time. I also picked up an oil filter, some 15W40 and an air filter. I should be able to get it inspected and registered now. Now comes the fun of dealing with the tax office. I probably should put some insurance on it, too.

Watch the wattage of the bulbs. I think brake and tail bulbs are the biggest culprits, not reverse, but a dual-filament HD brake bulb or the wrong taillight bulb can cause the sockets to melt.

1980sd · #14 01-29-2012, 08:06 PM

Quote:

Originally Posted by sethza

Dont start the car with ether, unless you need to take somebody to the emergency room or your escaping a tornado or something....

When did that become acceptable?

eatont9999 · #15 01-29-2012, 11:09 PM

Quote:

Originally Posted by Yak

Watch the wattage of the bulbs. I think brake and tail bulbs are the biggest culprits, not reverse, but a dual-filament HD brake bulb or the wrong taillight bulb can cause the sockets to melt.

Thanks for the heads up. I'll make sure I only buy bulbs with the same filament setup for the brake lights. The reverse lights are a single filament, so I that is what I will buy.