I am TRYING to replace the engine wiring harness on my 1995 C280. I started at the end on the passenger (right) side, have done the engine top, and am moving on to the engine front and toward the final connector on the driver's side in front of the wheelwell. That last connector on the harness is a long multipin device and I can not see how to remove it. I did discover what I believe is a slide-out lock at its base in the rear, but with it slid out the plug is still in there tight. It has to be lifted from the rear, where the wires enter, in order to come out, but I am afraid there is still something holding it. Can someone give me guidance here?

Also, on the same final connector, my new harness has one bundle of wires entering the housing while the old harness appears to have two bundles of wires going into the connector. Since I can't get it out, I can't see what the situation is on that. Both harnesses have the same part number. Any ideas?

And another thing, I cracked the housing of something trying to get another connector off. It is located on the head at the front of the driver's side (left) camshaft housing, is attached by two allen key bolts, and my guess is that it may be the tach sensor. Can someone indentify this for me?

Any help is appreciated. Thanks.

Starting fresh this morning, and with better light, I was able to solve the riddle of the connector. If anybody else needs to know, there is a U shaped slide around the plug, with the closed end at the front of the car. Two pegs on each side of the plug (at its base) fit into diagonal slots on the slide. Using a screwdriver at the closed end of the U, you can GENTLY work it toward the front of the car, which raises the plug up out of the socket as the pegs slide up in the diagonal slots. I believe the pull-out clip at the rear of the base serves as a lock.

Furthermore, there are indeed two bundles of wire coming out of this plug, and only one comes with the new harness. The second bundle is from another harness and goes to a separate plug which you must move from the old plug into the new one. This is easy, since it just slides out the open end of the old plug and you can see how it fits into the empty slot in the new plug.

hi there, I'm looking into replacing the wiring harness on my c280 as well... how much did your harness cost and where did you get it from? What is the p/n of the harness?
thanks in advance!

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95 M3 (US)
94 318is (EURO)
87 190E 2.6

The engine harness part number for '95 C280 is 202 540 40 32. I bought mine from BMA Importers in CA for $535. Local dealer quotes were $600 and $620, and would have sales tax added on. BMA's phone is 818-240-1223. I called several suppliers before them and was told the part is only available through a dealer.

It took me 10 hours over 2 days to do it, but I work slowly and carefully. What took the most time was figuring how to properly remove the harness coverings and some plugs without damaging anything.

Most of the plug layout is intuitive. Just start with the plug under the cover at the rear on the air filter side and work your way along. I would advise making a diagram or marking the plug positions at the front of the engine because they could be hooked up several wrong ways. Also in the front, you will have to remove a vacuum device to reach the plug behind it. When you do, be careful not to break the long brittle plastic line that leads around to the throtle actuator--I did, and had to splice it with rubber tubing.

Be careful removing the round plug on the "thing" at the right front side of the head on the camshaft housing (seen facing the engine from the front). It's housing is made of thin plastic and the back can break off pulling on the plug. Mine did and I just glued it back.

Last tip: the plug that goes down on the oil pan has another wire in the same bundle, and that wire goes on to make a connection at the starter. God knows how you are supposed to put that thing on without removing the starter, so I just left the old one in place and spliced the new one to it. Unprofessional, but VERY practical.

Good luck.

thanks for the info... I called up BMA, but unfortunatelly it seems that based on the VIN # for my car the wiring harness is different... p/n 202 440 79 05 - $760.00 it seems I have a newer version c280... anyhow, I'm trying to confirm the part # before I decide to order.... can you please tell me where to look in the engine bay for it... I lifted the computer cover up, but I'm not sure where the engine cover plus into as there are 4 big harness plugs.... any pics would help a lot, thanks again...

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95 M3 (US)
94 318is (EURO)
87 190E 2.6

>I lifted the computer cover up, but I'm not sure where the >engine cover plus into as there are 4 big harness plugs.... any >pics would help a lot, thanks again...

Sorry, I can't do pics for you because I traded the car in today on a 2001 C240. (I know--they have their problems too, but I liked it.) The throttle actuator was going fast, plus it needed lower control arm bushings, etc., so I bailed rather than put $3K into it. Had it for 7 years and hated to see it go, though.

Anyway, on my harness the tag with the part number was on the ground wire branching off from the main engine harness bundle coming into the compartment where you saw those 4 big plugs. (Under the cover at the left rear corner of the engine bay, as you stand facing the engine.) The engine harness plug is the one at the back right corner of that compartment. Look at that plug and you can see that the wiring from it leads out at the back right corner of the compartment, into a black plastic cover (that is a devil to get off) attached to the top of the firewall behind the engine, then emerges from the cover in a loop and goes over to the engine head. Now go back and look where the harness enters the compartment. You will see a wire branching off and following the wall of the compartment forward toward the front of the car and then around to the left where there is a ground lug in the front left corner. The tag is about 6 inches back from the lug.

got it, thanks... unfortunately this just confirmed the p/n BMA gave me I think I might trade it in too

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95 M3 (US)
94 318is (EURO)
87 190E 2.6