Evening gentlemen, I'm trying to get my paws on a new internal transmission wiring harness but cant seem to locate one. From what I understand, it differs from the standard XK8. Dealer has no part listed and Mercedes claims they never sold the harness separate. Any ideas?

 

It is called a CONDUCTOR PLATE.
I just bought a 'kit' from FCP Euro that has the plate, filter, connector seal etc.

 

Thank you sir, I'll look into it.

 

Be warned: the connector plate needs to be MADE BY MERCEDES.

I made the mistake of replacing my perfectly good original connector plate (just because it was 20 years old and “I was already there replacing the filter, etc.) with a generic aftermarket plate.

The connector plate contains the transmission temperature sender.

Now I have random “HIGH TRANS TEMP” warnings due to the shoddy quality of the Chinese manufactured part. Even sometimes when the engine is stone-cold. UGH ! Of course that never happened with the original plate, which was tossed long ago.

Save yourself some aggravation and don’t settle for less than the genuine Mercedes part. They are still available from some vendors.


Z

PS: the 4.0 liter XKR’s have a completely different transmission than the 4.0 liter XK8’s.
The 4.0 liter XKR’s use the made by Mercedes 722.6 transmission. It takes a specific fluid. Plenty of info on this forum on what ATF to use. It’s a very good transmission when properly maintained.

 

l don't disagree with the general Chinese quality verses original rule.
However, l had a gearbox issue some time back which led to the replacement of the conductor plate but the issue still remained. I eventually tracked the real culprit down to a plug on firewall not pushed all the way home, probably legacy of engine out by previous owner.
luckily l'm a horder so still have the original MB conductor plate as spare, but the Chinese replacement has not missed a beat in around 6 years motoring.

 

You are luckier, and smarter than I. But compared to many of the complicated issues I see posted here, I still have a degree of good fortune with these cars, when I leave well enough alone.


Z

 

Hahaha. That's my motto, benign neglect.

 

^^^^ that’s it !

Since the XKR (2002) is my daily driver I’m trying to get it to benefit from my natural obsessive compulsive nature. I practically double up on the simple maintenance items in my naive / primitive beliefs that by overcompensating on the simple things the car god(s) will give me a pass on the complex issues.

Can a person believe in science yet still practice superstition ? If so, that’s me.

Z

 

......And this is exactly my issue. Intermittent "HIGH TRANS TEMP", oddly enough no one mentioned its a conductor plate.....they (the shop/tech) all refer to it as a wiring harness so I was a little confused. Thank you all for clearing things up.

 

If you have a good code reader you can check the actual transmission fluid temperature, but only when the car is in R or D. A service bulletin explains why that’s the case. Upon checking, mine has always been normal despite what warning says. That’s one thing I don’t understand; how can the transmission temp sender provide the correct information to the code reader, but faulty information to the dash display ???

since I’m too lazy and too cheap, at this time, to buy another conductor plate my usual plan “B” is to wait a few seconds and the warning goes away on its own. A couple of times, as an experiment, I tried just restarting the car, which also clears it.

The extraneous HIGH TRANS TEMP warning hasn’t come on in a very long time. Maybe a
year or longer. So possibly the demon has moved on.

As far as shifting goes, my cars transmission is perfect. So I’m trying to stay calm about the whole non-issue issue.

Z

 

Jaguar issued a TSB to us when I worked at the dealer years ago.
If you look at the electrical guide, you will see a switch in series with the gearbox temp sensor.
The sensor is only connected in D or R.

 

^^^^^ this !

even though I had printed that TSB and gave it to my transmission tech, he insisted that his scanner could read transmission in Park or Neutral. Later, when I picked up the car he was uncharacteristically silent ….. lol

Z

 

Thank you for all the information guys, much appreciated.