Hello,
I just noticed that I have no brake lights on my 940T, and I also have no cruise control either however, the cruise has always been intermittent. Is this somehow related since they are both operated by the brake pedal? No blown fuse, and no bulb failure light either on the dash lights. I was hoping that the problem was a blown fuse, but no such luck. Shouldn't I have a bulb failure light, or some other indication? Thanks!

As I've written before, and is in the 700/900 FAQ, the cruise control imparts a small supervisory voltage on the brake light circuit, connecting to the brake light side of the switch. A bad brake light switch won't make the cruise control fail. Bad stop lamps will, but it is more likely to be a failure inside the the Bulb Failure Warning Sensor. It is the red cylindrical relay in the front left corner of the Central Electrical Unit.

Check your brake lamps first, and if they are good, remove the Bulb Failure Relay, and remove the cover. Look where the brake light circuit enters the relay on terminal 9 and follow the circuit. You'll find a spot that needs to be re-soldered. Sorry, I can't find a picture of the failure spot as I type this.

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john

Thanks boys! I have one or two of the red bulb failure sensors laying around,. I will troubleshoot with replacing it first, to see if it fixes the problem, and if it does, perform the repair that you speak of on the terminal #9 circuit. If that doesn't fix it, I will then go to the brake light switch, since it is more of a pain in tha @$$ to reach than the brake switch. Thanks again!

OK I used a spare bulb relay from a 240, and now I have a bulb trouble light on the dash, but I do have brake lights now. I had to break the little plastic guide pin off the 240 one to make it work, but it does have a different part#.

The one from the 240 is: 50KG 004 919-04

The one from the 940 is: the same, except the last two digits are 05. They appear identical in everyway, except the guide pin.

Are they interchangeable?

Bad brake light switch? I may be wrong but I seem to remember that if your brake light switch is bad your cruise will not work.

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95 855 GLT Sportwagon 214k, ex - 90 244 DL 300k