My 190d has the glow plug light staying on ,my idea is to replace the RELAY box with a junkyard piece .I had a look under my hood of my 300cd and the box looks very much the same .Can this be used instead of a 190d box.Id like to fix it before I ruin my new glugs Id just installed.

should be same. it's possible someone even upgraded to the afterglow relay they used in the 90's

They have different part numbers, 025 545 28 32 for the 190 and, see pic for the coupe.

Attached Thumbnails

 

__________________
83 SD

84 CD

One is for a 5 cyl 617 and the 190D is 4 cyl 2.2L. Physically the shape and the connectors 'may' be the same.

There may be one trick you can use. I thought about it before but never try it. You may be able to hook another GP to the spare 5cyl GP relay to trick it to think all 5 GP are there. You just look at the big connector and try to find the space pin and wire up a GP. It may work for the 190D. If you don't then the GP light may/may not come on with 1 GP missing.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Thanks ,Ill hook it up and give the result.

I made the modifications needed ,the piece mounts opposite of the original but theirs enough wire loose to remount it .Also thiers a extra plastic pin in one of the connections ,I just broke it off and whalla.The glow plug light goes off now after 5 secs, car starts right up after.This might be an easier pick in pull fix for those who cant find an original 2.2 pre glow module,just pull one from a 300d.

You mentioned the glow light is now on 5secs with the 300D relay. Can you recall how long it was on when the original GP relay was in good shape? The reason I ask is that my 2.2L 190D GP light only turns on for 1sec then goes off. I always thought it is too short but I have no way to know. I wait for a few sec and it always start first time.

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

The original 2.2 relay always stayed on ,so the module was bad ,the plugs were on all the time .With the new relay it goes for 5 secs and really seems to be ready to fire off with that amount of time .I do have another car ,300cd ,that a 1 sec light seems to happen ,Ill replace this one also and give you some feedback this weekend.