BenzWorld Junior Member
Date registered: Feb 2013
Vehicle: 1994 Mercedes C220, 1996 Chevrolet Tahoe LT
Location: Western Washington
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'94 C220 with new engine wiring harness won't start
This is my first post, although I have read through many, many threads on this site.
I have a 1994 C220 which I bought about a year ago with 88,000 miles on it. It has been very well cared for and it looks like it has had regular dealer service over the years. It has a couple issues but for the most part has been a great reliable car.
A few weeks ago I decided to replace the main engine wiring harness, since the insulation was seriously degraded in many spots. I took my time and did a very careful job over two weekends. However, when I got it all back together the car wouldn't start. It turns over and over and over but never catches, or even sounds like it wants to catch. Before I began the procedure it ran fine, starting every time with no trouble. While performing the harness replacement, I also replaced the coil harness.
I don't know if the problem is fuel or spark related, or if the engine management computer is preventing the engine from starting for some reason. I checked for spark at one of the plugs while cranking and there is none. I can't imagine that both coils would go out at the same time, but I am not sure if the computer will prevent the engine from starting if only one is malfunctioning.
I also changed out the OVP and the fuel pump relay and still nothing.
I have gone back through every connection in the entire engine harness and coil harness to double check that all connections are solid, and everything looks good.
I thought maybe it was an engine disabling security issue, but locking and unlocking the door with the key from the trunk and outside the driver's door didn't help.
I was very careful to be gentle with all the wiring near where I was working that I was not planning to replace, but I suppose it is possible that I inadvertently moved another wire with bad insulation that is now shorting out, although it seems unlikely to me.
I guess I could start replacing the crank sensor, maf, cam sensor, coils, etc, but I hate to just start throwing money at it if there is some simple solution that I am overlooking.
I also tried hooking up my ODBII scanner but for some reason it won't connect (it has in the past- I have pulled codes and reset the CEL a few times).
Is there anything that needs to be reset somewhere after disconnecting and reconnecting the battery?
Any help would be appreciated. Thanks!