96 volvo 850R cruise control not working

[phils94850]

I had a ABS light on my dash so I decided to open up the module and re-solder the joints and I also ohm tested my wheel abs sensors and found my right rear sensor was bad. I replaced the rear sensors and no more ABS light .

But... my crusie control still isn't working, I was thinking after fixing the ABS problem would fix the cruise but it didn't.. any ideas where to start on this problem ??

[erikv11]

The issue may be the ABS module, but if not:

By far most common problem is that vacuum line under the battery tray, the rubber elbow rots out so it doesn't hold a vacuum. Then probably the brake switch, but it could be elsewhere too.

There is a terrific troubleshooting guide in the Volvo manual, to systematically test each component. It is a 95 manual so you can't run the OBD box tests on your 96, but otherwise will be totally accurate for your car (e.g. jumper tests for the relay and the pump), download it from here:

https://www.matthewsvolvosite.com/downlo ... vo_850.zip

Once you unzip it there is a file called cruise control system.pdf, look there.

[mecheng]

Check that the rod ball joint is attracted to your gas pedal. My came off, 2 min fix

[erikv11]

That's a good tip, have never heard of that one!

[phils94850]

thanks guys... im gonna give it a good look over today

[phils94850]

ok.. i checked everything per the volvo repair manual.. i can remove the cruise control module and use a jumper wire and make the cruise control pump come on and suck down and hold my gas pedal so i know all that is working. I also checked the input and output of my cruise control switch and its working so im guessing the module is bad.

Is it often these modules go bad ??

[erikv11]

When I thought it was the module it wasn't, turned out to be a leaky vac line. But yours I can't figure.

I can send you a working module no charge, shoot me a PM if you want it.