1980 240d Glow plug relay source... - PeachParts Mercedes-Benz Forum

Keaner · #1 03-23-2009, 02:23 AM

So recently, My 240d has had a heck of a time starting up, taking a few minutes cranking before it'll catch.

I searched around here a bunch, and suspected the glow plug relay. I put in an order at the local napa for one, as well as glow plugs and a cleaner from mercedes source. I still haven't received the plugs, but they all ohmed out at about 1-2 ohm after I drove the car a while.

SO, I got the part from napa, and pulled the part that i suspected was the glow plug relay. It was a fairly large black box, right behind the driver side headlamp. However, teh NAPA relay doesn't look anything like it!

Did I get the wrong part, or are the glow plugs located somewher else? Where woudl I get the correct part?

Thanks!

toomany MBZ · #2 03-23-2009, 08:32 PM

Maybe, the early model gp relay is under the dash, a silver box, I think.
I understand 1980 was the transition year.
Click on the buy parts tab above for ordering info.

LAbioCars.com · #3 03-23-2009, 10:32 PM

Quote:

Originally Posted by toomany MBZ

Maybe, the early model gp relay is under the dash, a silver box, I think.
I understand 1980 was the transition year.
Click on the buy parts tab above for ordering info.

under the dash on the steering wheel

Diesel911 · #4 03-24-2009, 01:23 AM

I have not seen a good DIY write up yet on how to trouble shoot the "Silver Box" type of Glow Plug Relay.
I hope NAPA will let you return it.

brownrice78 · #5 03-24-2009, 10:47 AM

Some of the early 240s' have the sliver box under the dash. The later ones (most of them) have the black box next to the driver's side headlight assembly. Bosch makes the replacement black box glow plug relay. I actually just got one off a nice fella on ebay. It cost $40 shipped. Let me know if you want his email. I was having problems with the relay working when it wants to. Now, I just have to get around to using that glow plug reamer I got from Diesel911

Keaner · #6 03-25-2009, 02:34 AM

Thanks all for the replys!

I am troubleshooting a different starting issue now (key won't go into start), but while I was under the dash, I saw a similar looking silver-box under my dash. However, it has something like 12 smaller pins, isntead of 7 larger pins.

It was located on the left side of the car, under the dash. It was oriented so the long-way went with the car. However, I had traced the wires back from the glow plugs (at least i think so...) back to the box behind the headlight.

It is a little strange, it has two plugs, and a power cable on it. I had it out of the car at one point, which resulted in the car not starting at all (starter spun, but it was like there was no fuel). Is it possible that this controls fuel as well?

Sorry for being so dense on this topic, I bought this car to be a reliable daily driver, and didn't expect to have to do much work to it. I've been caught a bit unprepared.

If you could forward me the contact info of that gentleman with the black box source, Id be much oblidged!

EDIT TO ADD: I found the link on all parts express (i had searched before, and never found it): http://www.allpartsexpress.com/item.wws?sku=MBZ013124&itempk=57505&mfr=Stribel&weight=1.02
That image matches what I have exactly. Is this the one you got from your source?

brownrice78 · #7 03-25-2009, 01:22 PM

I PM'ed you the guy's email and phone #. Have you checked out the dieselgiant write-up regarding the glow plug

system?..http://dieselgiant.com/glowplugrepair.htm

does your car have the same set-up as the one shown? Or does it have the relay mentioned in this pictorial?

http://dieselgiant.com/mercedesdieselloopglowplugrepair.htm

Keaner · #8 03-25-2009, 02:52 PM

It has neither glow plug relay. It has the one from: http://www.allpartsexpress.com/item.wws?sku=MBZ013124&itempk=57505&mfr=Stribel&weight=1.02

As you can see, its very different than either of those.

I had looked at both of those, but neither seemed helpful.

brownrice78 · #9 03-25-2009, 05:39 PM

anyone have an idea what kind/type of relay that is???

thebenzbar · #10 03-25-2009, 07:33 PM

1980 models had the glow plug relay on the fender but it is a larger box than the ones seen 81-85 models... and much more expensive too (over $400).

Keaner · #11 03-25-2009, 07:35 PM

Quote:

Originally Posted by thebenzbar

1980 models had the glow plug relay on the fender but it is a larger box than the ones seen 81-85 models... and much more expensive too (over $400).

Yep, I've found that out the hard way! Napa wants 550 for one, so I was hoping some owner here had one by chance...

kerry · #12 03-25-2009, 08:07 PM

Now's the tmie to give serious thought to putting in a manual relay. Have you checked the plugs for voltage with the key in the glow position? In other words, what makes you think the relay is bad?

Keaner · #13 03-27-2009, 01:53 AM

I was giving serious thought into just piping the power cable right to the glow plugs through a dash switch.

I suspected the glow plug system because the car became really hard to start, which was consistent with a glow plug problem. I Ohm'ed all the plugs, and they were all about 1 ohm at max (after driving the car for a while). I read on here, that the relay was the most likely to fail.

My 240d has some sort of auto-timer for the glow plugs, so I don't think there is a specific 'glow plug' position, just the normal 'acc', 'on' and 'start', so testing it with the voltmeter becomes difficult. I ordered the relay, and some glow plugs anyway so I'll switch them out.

kerry · #14 03-27-2009, 09:48 AM

The glow position (acc position) should give you 20 or 30 seconds of glow, enough to get a voltage check to make sure it's working. It's easier if you have someone to turn the key to that position but not impossible to turn it then put the voltmeter on a plug. Glowplugs can ohm out fine but not be functional. I'd check both those things before installing a $400 part that might not be necessary. Glow plug relay failures are not that commonly reported here. Hard starts can also be caused by fuel or compression problems but more typically by bad glowplugs.

People who put in a a dash switch typically install a relay under the hood so that the full load doesn't have to come thru the dash switch. ForcedInduction's manual system is pictured on the forum here somewhere.

Keaner · #15 03-28-2009, 12:24 AM

Ok, cool! Thanks for the advice. If I cannot find the relay cheap, I'll try a manual system.

I'll replace the glow plugs anyway.