cruise control not intermittent to not working

[Ranger8867]

hello ive got a 88 ranger 2.9 manual it has cruise control and when I first got it. it would work but only with the headlights off and could not turn on the turn signals. also the coast button increased the speed. it worked like that for about a week then just stopped working all together. not sure where to even start to diagnose the issue. if you guys could point me in the right direction of what to check.

 

[superj]

Thats an odd problem. I wonder where the cc is grounded on the steering column, or should be grounded. Maybe its a broken ground, or someone accidentally hooked it to the wrong spot so it feeds through the lights now

 

[Ranger8867]

Could be haven’t looked into it a whole lot wanted to see where to start

 

[85_Ranger4x4]

Thats an odd problem. I wonder where the cc is grounded on the steering column, or should be grounded. Maybe its a broken ground, or someone accidentally hooked it to the wrong spot so it feeds through the lights now

Under the steering column, just inboard of the fuse block.

Electrical is part of it too, pretty much every issue I have had with my cruise was vacuum related.

Could be a broken cable too.

You are going to have to do some exploring.

 

[Ranger8867]

Ok and checked all my vacuum lines all are good there and grounds are good

 

[Ranger8867]

Cable is not broken either could it be the computer for the cruise control?

 

[RobbieD]

Sure is an odd issue, and the symptoms with other lights do make it sound like a ground problem.

Noted that "grounds are good"; specifically check G202 which is shown in the pages included. Make sure that the Lt Green brake input wire at the cruise amp is operating right: +12 volt brake on, and it HAS to have ground when the brake is off.
>>> Brake lights are filament style (incandescent) and working? LED bulbs don't play well with older cruise controls.

Check and clean the clockspring contacts (you'll have to pull the steering wheel). Cruise control switches use resisted ground signals via a single wire, and most trucks this age will have green crud on the contact tracks and pins. Use electrical contact cleaner, or rubbing alcohol, and a pencil eraser.

Check the servo throttle cable slack; spec is 6mm, or "as tight as possible without holding the throttle open" (see included page with Troubleshooting").

1988 EVTM cruise control pages follow; good luck!

 

[Ranger8867]

Oh man thank you so much and they are led rear bulbs so change them over as well as check the rest?

 

[RobbieD]

Oh man thank you so much and they are led rear bulbs so change them over as well as check the rest?

Yes, try putting original style rear stop/park bulbs in, see what the cruise will do afterward, and then take things from there.

Good luck!

 

[85_Ranger4x4]

There is also a vacuum dump valve on the brake pedal.

 

[Ranger8867]

Got it working! Can’t believe that it all because of the bulbs and think also the plug that goes into the computer one of the pins might have been falling out because when I unplugged it to test one wire fell out of the plug but it’s working perfectly even with the lights on thank you guys so much for the help

 

[RobbieD]

Good deal, and great work on your part.

Thank you for posting the resolution; it helps others down the road.