SOLVED: Crappy Hard Accel Shifts and Bouncy Cruise Control Tach
07-04-2010, 12:29 PM
#1
Super Member
Thread Starter
SOLVED: Crappy Hard Accel Shifts and Bouncy Cruise Control Tach
Can you guess what was wrong? Glorious Mercedes wiring. 
The more I work on this car, the more I realize: only a distinct few items are plagued with the crappy wiring, as the other half seem to be holding very well indeed (assuming the owner before me didn't replace those already). To be honest, it genuinely surprises me my ECU isn't fried by now.
It seems like the insulation formula was excellent for some wires, but incredibly shabby for for the most important stuff.
This time it is the transmission wiring harness. Notably, this harness also runs the 12+ power to the starter.
I started out looking for an ASR\CC\ISC wiring harness flaw but after 5 minutes of taking plastic off, it became apparent very quickly I found something that definitely and immediately needed fixing. This is pretty much a heads up\recall to all those reading owning a (95-96 ?) C36. You need to go out there and check this immediately.
Supplies for repair:
For the energetic and the willing (such as myself), this fix is no longer than a day old, even if you know absolutely nothing about pretty much anything:
The whole thing is very straightforward. The segment in question runs from right next to the ABS-actuator/proportioner, down and under the intake manifold, right above the crossmember and down the length of the transmission and around it, right along the exhaust hanger bracket.
Taking it all off in my case involved cutting a bunch of zipties and twomore things:
So just take the thing off, bring it home, draw the entire harness and measure each segment. Double check your work. Make sure each color is accounted for on both ends.
Front there it is cutting and soldering and zip-tying the thing along the way. One only tricky part is the 4-prong circular head transmission connector. It needs to be cracked open by force (crack off the top 'lid' portion of it), resoldered and sealed back together using Seal-All or something similar. This is an area that WILL get tons of moisture\water, so you really do not want to skip this step.
And now the part you all have been waiting for: the pictures. I was rather pissed so these did not turn out the best...
http://img15.imageshack.us/g/mercede...nsmission.jpg/
Before:
After:
The more I work on this car, the more I realize: only a distinct few items are plagued with the crappy wiring, as the other half seem to be holding very well indeed (assuming the owner before me didn't replace those already). To be honest, it genuinely surprises me my ECU isn't fried by now.
It seems like the insulation formula was excellent for some wires, but incredibly shabby for for the most important stuff.
This time it is the transmission wiring harness. Notably, this harness also runs the 12+ power to the starter.
I started out looking for an ASR\CC\ISC wiring harness flaw but after 5 minutes of taking plastic off, it became apparent very quickly I found something that definitely and immediately needed fixing. This is pretty much a heads up\recall to all those reading owning a (95-96 ?) C36. You need to go out there and check this immediately.
Supplies for repair:
- Exacto-knife
- Cardboard box cutter knife
- Adjustable wrench
- 13mm wrench (preferably the clicker closed end type)
- Allan socket set and a ratchet
- About $20 or more worth of wiring from NAPA (at least 16Ga and at least 6 different colors)
- Preferably some Seal-All or something else to pour as an anti-moisture fillant/insulant. Seal-all is great because its also gas and oil resistant
- Some soldering skills
- Tape measure
- Preferably wiring loom to guard from heat
For the energetic and the willing (such as myself), this fix is no longer than a day old, even if you know absolutely nothing about pretty much anything:
- Take old harness out: 1-1.5hrs
- Recraft the harness: 1-4hrs
- Put the harness back in: 1hr
The whole thing is very straightforward. The segment in question runs from right next to the ABS-actuator/proportioner, down and under the intake manifold, right above the crossmember and down the length of the transmission and around it, right along the exhaust hanger bracket.
Taking it all off in my case involved cutting a bunch of zipties and twomore things:
- The first exhaust hanging bracket needs to come off to undo the very last transmission connector
- The wiring is rucked under a hard metal line (AC or something hydraulic) which is being held by allan bolts
So just take the thing off, bring it home, draw the entire harness and measure each segment. Double check your work. Make sure each color is accounted for on both ends.
Front there it is cutting and soldering and zip-tying the thing along the way. One only tricky part is the 4-prong circular head transmission connector. It needs to be cracked open by force (crack off the top 'lid' portion of it), resoldered and sealed back together using Seal-All or something similar. This is an area that WILL get tons of moisture\water, so you really do not want to skip this step.
And now the part you all have been waiting for: the pictures. I was rather pissed so these did not turn out the best...
http://img15.imageshack.us/g/mercede...nsmission.jpg/
Before:
After:
07-04-2010, 04:20 PM
#2
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Join Date: Mar 2010
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12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG sold)
The C36's are harness problem makers. Sorry to hear and read that.
07-15-2010, 11:50 AM
#5
Super Member
Thread Starter
Ill try to remember next time I'm under the car.
Please rate the thread i f it is helpful.
I will also resize the pics for you guys.
EDIT: NVM, forgot how stupid these forums are. I cannot edit my own post.
Please rate the thread i f it is helpful.
I will also resize the pics for you guys.
EDIT: NVM, forgot how stupid these forums are. I cannot edit my own post.
