Intermittent Things: Cruise Control, Intermitent Wiper and Turn Signals - PeachParts Mercedes-Benz Forum

RobertFini · #1 03-27-2013, 03:54 PM

There are several functions that have lately begun working intermittently on my 1994 E320T.

The cruise control typically works perfectly, holding a very steady speed and keeping me out of the limelight when tooling down the highway. Unfortunately, it occasionally stops working for no apparent reason but will come right back to life when I turn the ignition off and then back on again (if on the highway, I'll do this while still rolling by kicking the car into neutral, turning the key off and then restarting right away). Once this happens and I "reboot," it's usually fine for the remainder of the trip.

The windshield wiper is another thing that's got me scratching my head: the intermittent setting sometimes works, sometimes doesn't (lately more not), but the two steady-on settings work just fine all the time.

Finally, the turn signals are acting up as well - sometimes working, sometimes not, with no apparent pattern. Thanks in advance for any insight.

I can't find any connection between these three issues, so they might be randomly unrelated, or maybe there is some common element that I'm not seeing.

Best Regards,
Rob

JamesDean · #2 03-27-2013, 04:05 PM

I would suggest cleaning connection points. Maybe you've got a wiring harness issue?

I was hoping I would be able to help out with your cruise problem but I believe the 94's cruise is integrated into another controller unlike the previous style of cruise controls

mbdoc · #3 03-27-2013, 04:17 PM

The wipers & turn signals are done by the combination relay in the rear of the fuse box.

Does the ABS light or the triangle light ever come on?

RobertFini · #4 03-27-2013, 04:54 PM

Quote:

Originally Posted by mbdoc

The wipers & turn signals are done by the combination relay in the rear of the fuse box.

Does the ABS light or the triangle light ever come on?

The ABS and ASR triangle lights only come on when they should - at startup and under slippy conditions.

RobertFini · #5 03-31-2013, 12:21 PM

I pulled out the combination relay and popped off the cover; a visual inspection revealed nothing obvious, so I reassembled it, cleaned off the contacts and put everything back together. Alas, nothing has changed, operation is still intermittent with no apparent pattern. I'm beginning to suspect the multi-switch, although it is possible that the relay is shot.

Is there any way to test the relay?

berryrice · #6 04-13-2013, 07:18 AM

Sorry I'm late to this discussion but here's a thread a while back that I posted a photo of that Combo Relay. You can actually fix it if you can solder bigger looking joints. My hazard, turn signals, and intermittent wipers ALL were on the fritz due to cracked/broken solder joints. The thread has the actually pics of the joints in question.

here's the link:
http://www.peachparts.com/shopforum/tech-help/313126-94-e320-intermitten-delay-wipers.html

Regarding you cruise control...sounds like it maybe your Throttle Actuator. It's the wiring insulation that goes belly up like the engine wiring harness...search for it and you'll find boat loads of info on it.

RobertFini · #7 04-19-2013, 01:16 PM

I purchased a new combination relay from Pelican Parts and it cured the problem - I will probably take a close look at the one I took out and see if it needs re-soldering, then hang onto it as a spare.

Thank you all for your help.

Best Regards,
Rob