Getting cruise control to work again

[hgeranium]

Howdy again everybody! 

 

For a good few years, my cruise control hasn't worked. It worked fine when I first got the truck, and randomly stopped working at some point.

 

I'm curious on where to start. The vacuum to the actual CC module is hooked up, although maybe the routing on the vacuum canister itself is messed up?

 

I imagine it could be the turn signal switch, but I do have a brand new one in there. A mechanic installed it back in 2022 so he may have made an error, but I hadn't had CC since before I replaced that part. I at least know he hooked something up wrong because I don't have high beams so it may be worth my time to take the wheel off and check it out regardless.

 

[eaglescout526]

Ahhh cruise control. 
 

It’s simple, yet complicated when first diving in. 
So the turn signal switch has nothing to do with cruise. The turn signal stalk with the cruise switches in it actually has a wire for those switches that runs down to a harness and that harness has other things plugged into it. 
 

There’s an inline fuse. I’d check that. 
The module isn’t know you exactly die but they are getting up there in age. 
Vacuum lines rot and crack, check the hardliners and rubber lines. 
The dump valve could’ve come out of adjustment. Located above the brake light switch. 
servos rarely die but they can. 

 

There’s some starting points. 

[hgeranium]

5 minutes ago, eaglescout526 said:

Ahhh cruise control. 
 

It’s simple, yet complicated when first diving in. 
So the turn signal switch has nothing to do with cruise. The turn signal stalk with the cruise switches in it actually has a wire for those switches that runs down to a harness and that harness has other things plugged into it. 
 

There’s an inline fuse. I’d check that. 
The module isn’t know you exactly die but they are getting up there in age. 
Vacuum lines rot and crack, check the hardliners and rubber lines. 
The dump valve could’ve come out of adjustment. Located above the brake light switch. 
servos rarely die but they can. 

 

There’s some starting points. 

Awesome. Thank you so much! May be a dumb question but where would I find that inline fuse? I know of one for sure in the engine bay but making sure that's the right one. I think it's right next to the battery.

[hgeranium]

https://naxja.org/threads/how-to-test-repair-renix-era-cruise-control.1160060/

 

Putting this here for myself and future viewers.

[hgeranium]

"The cruise control in these vehicles will NOT work if you have changed your brake lights to LED."

 

Found at least one of the causes.

[eaglescout526]

1 hour ago, hgeranium said:

Awesome. Thank you so much! May be a dumb question but where would I find that inline fuse? I know of one for sure in the engine bay but making sure that's the right one. I think it's right next to the battery.

So the fuse is connected to a white with black tracer in the fuse block. Follow it and it should have a 3 or 4 amp fuse in it. 
 

I can see LEDs being an issue. 

[pizzaman09]

4 hours ago, hgeranium said:

"The cruise control in these vehicles will NOT work if you have changed your brake lights to LED."

 

Found at least one of the causes.

That is interesting.  I changed one of my two brake lights on each side to LED.  The cruise still works.

[hgeranium]

5 minutes ago, pizzaman09 said:

That is interesting.  I changed one of my two brake lights on each side to LED.  The cruise still works.

Hmmm. I wonder if the guy in the thread I linked mentioned it anecdotally. 

[pizzaman09]

1 minute ago, hgeranium said:

Hmmm. I wonder if the guy in the thread I linked mentioned it anecdotally. 

Well I still have a set of incandescent bulbs in it too, so it really does still act like the original incandescent setup.

[AnotherOldJeepGuy]

23 hours ago, eaglescout526 said:

So the fuse is connected to a white with black tracer in the fuse block. Follow it and it should have a 3 or 4 amp fuse in it. 
 

I can see LEDs being an issue. 

If you locate the fuse, please post of picture to help locate it.  Mine doesn't work either, I have a brand new column switch, and no LED lights.  Would be nice if a fuse would fix it...

[eaglescout526]

47 minutes ago, AnotherOldJeepGuy said:

If you locate the fuse, please post of picture to help locate it.  Mine doesn't work either, I have a brand new column switch, and no LED lights.  Would be nice if a fuse would fix it...

It kinda varies on how tucked into the main harness it is. Best way I can say to locate it without going to my Jeep while im working is there’s a slot labeled “ign” on the fuse block itself. Should have a brown connector plugged into it that will be a black and white wire that should travel a short distance to a inline fuse connector with a fuse that should be pink in color. 

[pizzaman09]

My cruise had stopped working recently.  After going through the NAXJA thread and everything proved out.  But I had noticed that the pins on the connector looked crushed so I re-tensioned pins and now my cruise works flawlessly.  I suspect the pins became messed up when I was recently working on some stuff under the dash and had unplugged the cruise yellow box.  

 

Hopefully this helps someone when everything is checking out well.

[eaglescout526]

17 minutes ago, pizzaman09 said:

unplugged the cruise yellow box

At least we aren’t treating the connector and control module like a NES cartridge haha. 

[Tactical Bacon]

On 10/1/2025 at 3:25 PM, hgeranium said:

"The cruise control in these vehicles will NOT work if you have changed your brake lights to LED."

 

Found at least one of the causes.

Any idea if that's Renix only or HO, too?