190D eating glow plug relays - PeachParts Mercedes-Benz Forum

jaoneill · #1 12-04-2006, 03:22 PM

I could really use some help on this one; electrical problems are really not my forte.

Pre-glow timer (glow plug relay) on my '84 190D daily driver crapped out back in early November. Replaced it with one of the new and improved "upgrade" relays. It lasted less than a month, died last Friday. Borrowed the relay from my '85 190D, installed it Friday afternoon, all worked as it should. Have started the car maybe 15-20 times since and it now appears that this relay is cooked. Came out of a 2 hr lunch meeting today and had no glow light (or glow plug action; almost didn't start).

Can't imagine what is causing these things to fail, but fail they have. On Friday when I installed the latest relay in the '84 I also tried the two previously inop relays in the '85, with no results, so I am relatively certain that they are dead.

I have another relay on the way from Phil, but at $164 apiece I almost hate to install another one in the '84 if there is something else that may be causing these premature failures. Prior to this I have had no glow problems at all.

Saw a post by rrgrassi indicating that QC may be an issue with these relays but the last one the '84 cooked was not new and had been working just fine in the '85.

Any advise sincerely appreciated,
Jim

barry123400 · #2 12-04-2006, 06:32 PM

Easy stuff first. Check all the resistances of your glow plugs as one may be almost a dead short. That should have taken the strip fuse out though so is probably not a good candidate. Next I would find the relays ground leg. If this has some resistance it may be shunting more current through another circuit in the relay to attempt to complete a ground than it was designed to take. It may pay dividends to open up one of the now defunct ones and see what if anything has overheated and burnt out.. Thats where I would start first. It might give you a clue as to what is happening.

jaoneill · #3 12-04-2006, 06:44 PM

Thanks Barry,

Will open up one of the inops and see what there is to see. Will also check the plugs but, as you have indicated, they are probably ok, with one glow cycle it didn't spin a full turn this morning before it started (at ambient 11f).

Jim

jaoneill · #4 12-04-2006, 06:57 PM

Duh,

Hey Barry, your first easy thing was an excellent shot, I didn't get much further than getting an inop relay off the shelf. Strip fuse under the cover is blown. As you advised, next step glow plugs (and a new strip fuse).

Thanks a million, Jim

Samuel M. Ross · #5 12-05-2006, 10:20 AM

Quote:

Originally Posted by jaoneill

Duh,
Hey Barry, your first easy thing was an excellent shot, I didn't get much further than getting an inop relay off the shelf. Strip fuse under the cover is blown. As you advised, next step glow plugs (and a new strip fuse).
Thanks a million, Jim

Jim,
Your plight is exactly why IF/WHEN I face a relay/timer replacement, I'm going to retrofit my 240D with a manually powered GP system that merely has a pushbutton somewhere on/under the dash. As I see it this would also serve as a theft deterrent!

Be certain to let us know what you find... shorted GP, whatever!
Regards,

Parrot of Doom · #6 12-05-2006, 10:27 AM

Where can I buy the strip fuses from? I have an OM606 glow plug relay with a couple of these burnt out. I could replace them and sell it.

Samuel M. Ross · #7 12-05-2006, 11:54 AM

Quote:

Originally Posted by Parrot of Doom

Where can I buy the strip fuses from? I have an OM606 glow plug relay with a couple of these burnt out. I could replace them and sell it.

These should be less than $2 at a Dealer's parts counter so that makes more sense than mailordering it.
Regards,

jaoneill · #8 12-05-2006, 05:31 PM

Quote:

Originally Posted by Samuel M. Ross

These should be less than $2 at a Dealer's parts counter so that makes more sense than mailordering it.

Unless, like me, you are 150 miles from the nearest dealer (who seldom stocks what I need for 20+ year old cars). I will let you know the results as soon as I get to the project. My garage is unheated and it is currently 12 cold, damp degrees so I may not get to it tonight.

Regards,
Jim

Samuel M. Ross · #9 12-05-2006, 06:15 PM

Quote:

Originally Posted by jaoneill

Unless, like me, you are 150 miles from the nearest dealer (who seldom stocks what I need for 20+ year old cars). I will let you know the results as soon as I get to the project. My garage is unheated and it is currently 12 cold, damp degrees so I may not get to it tonight.
Regards,
Jim

Surely someone there in the N.E. could be convinced to mail one of these tiny, flat, fuses... let me see, I think Brian Carlton is from N.Y.
Come on NewEnglanders, someone arrange to send Jim one of these things... don't make him wait until he has enouth to make up a mailOrder order!
Regards,

jaoneill · #10 12-05-2006, 06:53 PM

Hey Sam, I appreciate your conern but I remembered that I had another older relay out in the parts shed, just went out and checked. Lo and behold, it has a good fuse in it, so I am golden. I will put the fuse in the '85 and drive that until the parts are assembled and then do the whole job on the '84 in one shot.

Am about to place an order for a few more strip fuses, a new set of glow plugs for the '84, and enough oil filters to make up an order (with the mileage I put on the MB's I change oil about every 3rd weekend, I can always use filters). If Phil has such an animal I will also get a new glow plug wire harness, just hate to do something halfway and then do it again when I can least afford the time (which is generally when something craps out).

Thanks again,
Jim

jaoneill · #11 12-11-2006, 09:05 AM

and related issues. Update: All parts gathered (new glow plugs, strip fuses, intake manifold gasket, relay - just in case). Pulled air box and intake manifold; checked resistance on gp's (all ok), installed new gp's (all came out uneventfully and clean), followed wire bundle back from engine and found the problem.

Wire bundle had been rerouted under power steering pump (not factory path) and had been rubbing on something. Braided wire loom was crispy, an 8" section was non-existent; wires were melted together, bare, some burned through. Repaired wiring, installed new section of wire loom, re-assembled air intake, installed updated relay. Elapsed time - 2 1/2 hrs. Started car several times - all appears to work as it should. It remains to be seen, but this may also solve the intermittant electrical issue that I have had with the parking lights for the past two years.

Thanks again for the help,
Jim

Samuel M. Ross · #12 12-11-2006, 10:37 AM

Quote:

Originally Posted by jaoneill

and related issues. Update: All parts gathered (new glow plugs, strip fuses, intake manifold gasket, relay - just in case). Pulled air box and intake manifold; checked resistance on gp's (all ok), installed new gp's (all came out uneventfully and clean), followed wire bundle back from engine and found the problem.

Wire bundle had been rerouted under power steering pump (not factory path) and had been rubbing on something. Braided wire loom was crispy, an 8" section was non-existent; wires were melted together, bare, some burned through. Repaired wiring, installed new section of wire loom, re-assembled air intake, installed updated relay. Elapsed time - 2 1/2 hrs. Started car several times - all appears to work as it should. It remains to be seen, but this may also solve the intermittent electrical issue that I have had with the parking lights for the past two years.
Thanks again for the help,
Jim

Jim,
Because I feel like I understand them more, I often try to help out on electrical related problems and in your case I have never looked under the hood of your MODEL MBz. So just now as I read your account and final report on the cause of your car's problems [thanks... a good, complete, report], I decided to take a look at the basic "specs" for your car which confirm what I think is the case:
Chassis.........Engine...........Model.......Years........HP......Weight
201.024.....102.985/I4 2.3L......190E.......1984-86......121......2745
AND this makes me realize that you have a light-weight, probably smaller in size, turbocharged MBz that in all likelihood is crowded under the hood in comparison to our two 1980(s) 240D & 300D without turbos.
In my mind, this explains such a meltdown going unnoticed! So for the rest of you readers out there, keep this in mind before you rush to purchase ANY car that is crowded under the "bonnet"!

This is why I'm a pickemUPtruck kind of guy... stuck in an uban center with little need for my favorite kind of vehicle! You should see the mint condition VW unibody diesel P/U a local independent shop owner has... what I would give for that!
Regards,

jaoneill · #13 12-11-2006, 08:34 PM

Quote:

Originally Posted by Samuel M. Ross

Jim,
Because I feel like I understand them more, I often try to help out on electrical related problems and in your case I have never looked under the hood of your MODEL MBz. So just now as I read your account and final report on the cause of your car's problems [thanks... a good, complete, report], I decided to take a look at the basic "specs" for your car which confirm what I think is the case:
Chassis.........Engine...........Model.......Years........HP......Weight
201.024.....102.985/I4 2.3L......190E.......1984-86......121......2745
AND this makes me realize that you have a light-weight, probably smaller in size, turbocharged MBz that in all likelihood is crowded under the hood in comparison to our two 1980(s) 240D & 300D without turbos.
In my mind, this explains such a meltdown going unnoticed! So for the rest of you readers out there, keep this in mind before you rush to purchase ANY car that is crowded under the "bonnet"!

This is why I'm a pickemUPtruck kind of guy... stuck in an uban center with little need for my favorite kind of vehicle! You should see the mint condition VW unibody diesel P/U a local independent shop owner has... what I would give for that!
Regards,

Sam,

Your reasoning is accurate. My 190D is a 2.2 NA diesel, but there is not much room on that side of the engine compartment. Air box / intake manifold / power steering pump / fuel filter all across the top. Only two or three inches between air box & fender well. This is why I removed the air box and manifold to change the gp's (also required to access IP, primary fuel filter, most fuel lines, etc, etc.). I must say though, removal and re-install is only a 10-20 minute job, small price to pay for 40+ mpg.

Jim