I have a 1995 SL500. CEL came on - checked codes - MAF out of range. I did the following:
- Checked wiring harness for shorts/opens and intermittants - harness OK
- Cleaned MAF - Reset codes - Ran without CEL for a day - CEL on again
- Checked codes again - MAF out of range
- Ordered Bosch rebuilt AMM
- Car drove ok for a day or two with CEL on then began to stall. Disconnected MAF and the car ran great
- Replaced AMM - CEL went out - car ran great for two days
- After filling up my tank, the car stalled and would not start again
My question is, before I send the AMM back, is there something I sould look at.
I'm driving with the AMM disconnected and the car runs great.
Thanks

Wiring Harness issue; ALL
http://www.peachparts.com/shopforum/showthread.php?t=166883





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But he said he checked the harness and it was OK.

However, I have been fooled more than once by these biodegradable wire harness issues.

Here is how I tested the harness:
- Disconnected the MAF sensor
- Continuity check between each of the five wires and all the others-ok
- Continuity check between each of the wires and chassis - only one grounded as it should be-ok
- Disconnected the large connector next to X11-4
- Checked all five wires for continuity to the large plug -ok
Anything else to check? I don't want to rip the harness up to visually check the wires. Wiring to injectors & cam magnets new and in good shape. No codes for anything but MAF range.
I tried to twist the MAF connector and see if there was an intermittant problem but that is rather difficult to do and see. When the car stalled I also twisted the wire and connector with no results. When I disconnect the MAF sensor, car starts and runs well.
I'm going to re-install everything tonight and see if the problem is still there. Also going to check fuel pressure and get a new gas cap(127000mi). If the problem persists, I will return the AMM for another one. Does anyone know what OBDI code is set by a defective gas cap?
I am trying to find a wiring harness at a resonable price. I rufuse to pay $1600 for a harness when it should of been replaced at MB expense.

Turned out to be the MAF 5 pin connector. The internal O-Ring had deteriorated and kept the connector from seating properly.When I torqued the connector with some force the car would stall. I installed a new O-ring from my junk box - you can now torque the connector all day and it still makes a good connection. It's always the little things - Thanks all.

Are you serious - a new wiring harness now costs $1600? I bought one for a 119 motor less than two years ago for a little over $500.

Contempory Motor Cars - Only MB dealer in Erie PA - $1600. "Are you serious" was my reaction too. I ended up redoing the harness myself with good results. I would like to get a new harness and $500 is more like it. Where did you get yours?

Caliber Motors in LA @ 800-252-6877. Park Place in Dallas @ 214-526-8701 is another good mail order dealer. Let us know what you find.

Caliber Motors has them in stock - $550. I will have it tomorrow. Many Thanks.

We have this Forum, free, free, free. We only ask that you support us a little. I can't beleive you'd send our members to a Dealer and not to Fastlane
Thank you for the support....
That's how we pay to keep this Forum going 24/7

Partsman

Conventional wisdom - to which I subscribed - was that wiring harness is a dealer only item. Sorry, didn't know you had it.

Phil at FastLane has direct access to all Dealer parts, plus a HUGE list of components no longer offered by MB.

This is why I keep repeating; Call Phil first with parts questions.

Many people do not seem to notice this statement on the FastLane front page.

If you can't find what you need in our catalog
simply call or e-mail Phil for assistance.
Phil has access to MANY MORE PARTS than shown here!
Toll Free 1-888-333-4642 or philip@peachparts.com

NOTE:
Always mention that you are a mercedesshop forum member...

I am the one who requested the info - a member was kind enough to respond quickly and in good faith. I assumed everyone had the same opportunity. No matter, in the end I should have and gladly would have called Phil first - Please don't blame another member for my ignorance. I enjoy the forum and will always support it every way possible.