1990 240DL dies now

Eric Kropp · Post by **Eric Kropp** » 17 Oct 2010, 20:36

So I have had this on going thing with my daughters 1990 240DL station wagon. I pulled the instrument cluster some time back. long story short, when I put in back the right turn arrow did not work, the dash lights that dim with the head lights didn't work the cruise control didn't work and the speedometer was way out of wack. I have slowly been restoring all the things that I screwed up. I had it to the point that the only thing wrong was the cruise control. I found that I had the white and red wire plugged in to the cluster that is for a car with a tach. That was responsible for the speedo-wackness and maybe popping some bulbs. Since then I changed the cruise/turn signal/dimmer switch with one from an '86 model, because it fell apart. I thought it would work so I wired it in. Shortly after that my daughter said the car started dying as she drives down the road. Do you guys think this could be because I wired the wrong cruise control switch into the car and smoked something in the delicate electronics, or do you think this is unrelated and coincidental, and I should look elsewhere? It ran a long time with the white and red tach wire plugged in...so my guess is that shouldn't have cooked anything, but so far not much I've done has been right according to my guesses.

Eric

Post by **billofdurham** » 18 Oct 2010, 11:58

Which model was the '86 as I can't find a reference to cruise control on the 240 of that year? I was checking wiring diagrams for the '90 and the '86 to see if there had been a change of wiring colours. I have also checked the specs for the '86 and no cruise is mentioned.

As you say, the thing was wired up wrong for a long time so if electronics were going to fry it would have been sooner rather than later. Has it thrown any fault codes since the current problem started?

I have a full check sequence for the cruise control which tests the ECU, switch, vacuum pump and lines. If you think it would be useful let me know and I'll put it on.

Bill.

Eric Kropp · Post by **Eric Kropp** » 18 Oct 2010, 15:51

Haven't checked any fault codes. It ( the cruise control ) was not wired up for a long time, just over night and the next day until I clipped them hoping it would all be better...not so. That white wire with the red stripe on it that goes to the tach was plugged in for quite a while. I think it all kinds of affect on things like the instrument lights speedometer and cruise control, but never affected the running of the vehicle. My wife said it died on here at least 2 out of 4 times she let off the throttle to slow down. I found the cruise schematics for 83 to 85 then 86 to 89 then 90 to 93 in the manual I have. It is not a Chiltons or Clymer, I think it is a Bennetts (?) manual.

Thanks,
Eric