Attention: TDR Forum Junkies 
Shelby Griggs
TDR MEMBER
My cruise control has been acting up intermittently. It will sometimes cut out, sometimes seems to want accelerate beyond set point when trying to set, other times it works fine. It also seems affected somewhat by temperature, not sure if cabin temperature, outside temperature or engine temperature AND at least some times seems related to bumps in the road.
I haven't found too many old threads dealing with issues with the ALL electronic CC on the late 2nd gen trucks with manual transmission.
As I understand, all electronic with these inputs: wheel speed (ABS) sensor on rear differential, the steering wheel switches and the stop lamp switch. Am I missing any other controls?
I replaced the speed sensor on the rear differential housing with a Dorman aftermarket from Geno's (it had been replaced once before by a shop for ABS light on, also likely also aftermarket). I replaced the stop lamp switch with one from NAPA (and have an OEM on on backorder from Geno's). I have a set of used switches for the steering wheel, but haven't tackled that yet. Can't seem to find a new set of switches anywhere. At least this used set looks like way less miles than mine, all the lettering is still in like new condition.
Today I drove some short trips in the AM, about 50F outside and then around noon about an hour drive, all worked fine. Stopped for lunch for about an hour, then another hour home, after lunch it never did work correctly. Generally I have noticed first trip of day seems to work ok. Sometimes later in day works too. At first I though ABS sensor heating up or engine ECM, however these would be up to temperature way before things start acting up, so now leaning toward outside temperatures or cabin temperatures being warmer, today was around 80F after lunch.
Not always, BUT the cutting out or stuttering when hitting a bump leads me to believe something like the stop lamp switch and the peddle vibrating causing stop lamp switch movement, but with a new switch??? I had read someplace that ONLY the OEM switches worked reliably, but find it hard to believe an Echlin brand switch from NAPA wouldn't be up to spec.
Other theory's are intermittent wiring in the tilt column or a bad clock spring (it was replaced as a recall years ago, but still old now). I have 330K miles, BUT I never tilt the wheel unless I need to work on something in/on the dash, it probably hasn't had more than 100 cycles in 22 years, so I can't imagine wiring would have a break, but anything is possible.
No codes are set in the odometer, haven't hooked a scan tool to the OBD2 port. Would need to borrow one or take it to a shop.
I can continue throwing stuff at it, BUT any input appreciated, maybe there are other controlling inputs I am missing? There is the clutch switch, but I am unclear if that is an input or not, pushing the clutch (normally I think) disengages cruise, BUT I think that is due to rapid increase in engine RPM, not the switch? That switch normally doesn't engage and let starter operate until clutch is fully depressed.
This has me kind of baffled.
I haven't found too many old threads dealing with issues with the ALL electronic CC on the late 2nd gen trucks with manual transmission.
As I understand, all electronic with these inputs: wheel speed (ABS) sensor on rear differential, the steering wheel switches and the stop lamp switch. Am I missing any other controls?
I replaced the speed sensor on the rear differential housing with a Dorman aftermarket from Geno's (it had been replaced once before by a shop for ABS light on, also likely also aftermarket). I replaced the stop lamp switch with one from NAPA (and have an OEM on on backorder from Geno's). I have a set of used switches for the steering wheel, but haven't tackled that yet. Can't seem to find a new set of switches anywhere. At least this used set looks like way less miles than mine, all the lettering is still in like new condition.
Today I drove some short trips in the AM, about 50F outside and then around noon about an hour drive, all worked fine. Stopped for lunch for about an hour, then another hour home, after lunch it never did work correctly. Generally I have noticed first trip of day seems to work ok. Sometimes later in day works too. At first I though ABS sensor heating up or engine ECM, however these would be up to temperature way before things start acting up, so now leaning toward outside temperatures or cabin temperatures being warmer, today was around 80F after lunch.
Not always, BUT the cutting out or stuttering when hitting a bump leads me to believe something like the stop lamp switch and the peddle vibrating causing stop lamp switch movement, but with a new switch??? I had read someplace that ONLY the OEM switches worked reliably, but find it hard to believe an Echlin brand switch from NAPA wouldn't be up to spec.
Other theory's are intermittent wiring in the tilt column or a bad clock spring (it was replaced as a recall years ago, but still old now). I have 330K miles, BUT I never tilt the wheel unless I need to work on something in/on the dash, it probably hasn't had more than 100 cycles in 22 years, so I can't imagine wiring would have a break, but anything is possible.
No codes are set in the odometer, haven't hooked a scan tool to the OBD2 port. Would need to borrow one or take it to a shop.
I can continue throwing stuff at it, BUT any input appreciated, maybe there are other controlling inputs I am missing? There is the clutch switch, but I am unclear if that is an input or not, pushing the clutch (normally I think) disengages cruise, BUT I think that is due to rapid increase in engine RPM, not the switch? That switch normally doesn't engage and let starter operate until clutch is fully depressed.
This has me kind of baffled.
