Slow starting / Glowplug system?

My wife told me yesterday that her car has started to not start as fast as is used too. Last night when I took it to the store I noticed that the glow plug light didn't come on. Thinking this was a little odd, I opened the door and recyled the key. I didn't here the "click" that the GP relay normally makes. WHat are some other things to check out? The GP's are new as of last summer. So it shouldn't be that. If it is the GP relay, where is it, can i test it, and how much does a new one cost. Would a junk yard part be just as good as a new part?

Thanks fo the help.

[Brian Carlton]

The glow plug relay is on the driver's fenderwell, forward side. It is a rectangular box, approximately 2" x 4" x 4" deep.

Connect a voltmeter to one of the glow plugs. Turn the key to the #2 position. See if you have 12V at the plug. If you do have 12V, then one of the plugs is suspect.

If you do not have 12V, check the 80A fuse that is underneath the cover of the rectangular box. It is a copper? plate that sits between two large phillips screws. Sometimes this cracks with age. Sometimes you cannot see the crack. Take it out and look it over carefully. If you have any doubts about it, replace it.

If the fuse is good, then the relay is suspect. A junk part will function as good as a new one, however, the new one will last longer.

Originally Posted by Brian Carlton

The glow plug relay is on the driver's fenderwell, forward side. It is a rectangular box, approximately 2" x 4" x 4" deep.

Connect a voltmeter to one of the glow plugs. Turn the key to the #2 position. See if you have 12V at the plug. If you do have 12V, then one of the plugs is suspect.

If you do not have 12V, check the 80A fuse that is underneath the cover of the rectangular box. It is a copper? plate that sits between two large phillips screws. Sometimes this cracks with age. Sometimes you cannot see the crack. Take it out and look it over carefully. If you have any doubts about it, replace it.

If the fuse is good, then the relay is suspect. A junk part will function as good as a new one, however, the new one will last longer.

I read in a thread here recently that the dash glow light will not come on if two or more GP's are not working. With only one bad GP, the dash glow light will still come on. Chances of two recently new GP's failing isn't likely, and as Brian has already mention, the fuse inside the GP relay box may be blown, or have corroded too! Hopefully it is corroded because if it is blown there is a reason for that such as the relay it's self going bad! BB

Thanks for the replies. I will be checking the fuse ya'll are talking about when I get home this evening. It shouldn't be the GP's as I replaced them all lass than a year ago.

I don't know if it's a realted problem or not, you know how these MB's can be. The car is a wagon. Last week my wife calls me at work to tell me that the rear cargo light is on and it won't turn off, no matter what she does to it. She finally had to remove the bulb. Is this a tattle tale for something or is this an unrelated problem?

I was pokeing around last night under the hood and have a couple of questions. I found two boxes on the drivers side that are approx 4x4x2. One of them has two fuses inside of it and I can't tell were the wires go too. It's mounted on the top of the wheel well. THe other one is mounted vertically on the side up close to the headlight. I can trace out the wires leaving it, and they go directoly to the glow plugs. I have a feeling that this is the box that's being referred to above. Is the 80A fuse inside of this box?

Also, On the passenger side mounted to the fender is a little metal box. Approx 3"x3"x4". It has a bunch of holes in it and has what looks like some springs (or coils) inside of it. I think this is the little device that used to click when the GP's where activated. But right now I don't get anything.

Please shead some light on this for me.
Thanks,
Chris

[Brian Carlton]

Originally Posted by cmichalik

THe other one is mounted vertically on the side up close to the headlight. I can trace out the wires leaving it, and they go directoly to the glow plugs. I have a feeling that this is the box that's being referred to above. Is the 80A fuse inside of this box?

Also, On the passenger side mounted to the fender is a little metal box. Approx 3"x3"x4". It has a bunch of holes in it and has what looks like some springs (or coils) inside of it.

That's the glow plug relay. Slide the cover off to reveal the 80A fuse.

That is the resistor bank for the fan motor that moves air for the climate control system. When you run the fan at any speed less than full speed, some of those coils are in series with the fan and cut down the voltage to the fan.