P32 Cruise control doesn't work

[gunterm]

My forum search only turned up W22 chassis answers and mine has the old Chevrolet 90s style cruise so I assume the troubleshooting process is different.

I did some testing of the stalk and suspected a bad switch so it was replaced with an exact GM part, still no cruise. I have no light on the dash so there's no way to tell if anything is working unless I go drive faster than 35 and try to SET.

I'm looking for the Cruise fuse next, beyond that I'm out of ideas...

[tomwalt]

See attached wire list.
Sheet 34 (pdf sheet 8 of 25) shows the fuse as #9. Sheet 10 (pdf sheet 3 of 25) shows fuse 9 also feeding the ABS.

Also on sheet 34 note the brake "stop light switch" off to the right of the cruise control module. There are 2 switches on the brake pedal arm that are easy to bump loose - check them too (check to see if your brake lights work correctly).
http://workhorse.navistar.com/workho...7_4_engine.pdf

[gunterm]

Cruise fuse is okay, however I figured out why my ABS light is on and won't go off. The BRAKE fuse is blown and re-blows every time it's replaced instantly after turning the key on so I fear my ABS module is fried. Since the cruise and ABS seems tied together this is evidently why it doesn't work.

Where can I start with the ABS system?

[56llama]

Before you going into the ABS system check out the main harness plug which is in the column by the steering wheel my cruise control didn't work two years ago and I took the plastic covers off by the steering wheel and it turned out to be a harness plug was separating on one end

[gunterm]

Shop fixed my ABS problem, they said it was the brake lamp switch wire, it had shorted somewhere and was causing the light. They cut and ran a whole new wire and fixed the light however still no cruise. I'm going to look for those 2 brake switches where are they on the pedal?

The main harness traces back OK.

[Full.Monte]

I would look for the permanent magnets that send the signal to the cruise control about drive shaft speed. Sometimes the glued-on magnets get loose and fly off. Also, the sender unit must be close enough to the magnets for them to energize the sender unit. I don't exactly remember where to tell you to look, but someone else may.

[gunterm]

Found two switches, one loose and I pulled it out for show. I stuffed a little pad in between the switch and that piece of wood so it's snug now. I'll try a test drive later to see if it's fixed.

[gunterm]

[bob_5297]

That is for the cruise control to shut off when you apply the breaks

[bob_5297]

They have nylon nuts that dry up and break. Just replaced my own. Both switched brake light switch and the other is a cruise control cancel switch

[gunterm]

Originally Posted by bob_5297

They have nylon nuts that dry up and break. Just replaced my own. Both switched brake light switch and the other is a cruise control cancel switch

You replaced the whole switch? Where can I get replacements?

[bob_5297]

i got them at my local parts store. when i first asked if they had one they said didn't have them so i took them both in and they cross referenced the GM numbers. they had both.

[CA Harts]

I had the same problem with the switch and the cruise control not working. I replaced the switch and works fine now.

[bob_5297]

Originally Posted by gunterm

Attachment 141941

It appears that yours was broken before from the nut that is still on it. That is not stock. And it looks like they might have put some wood behind it to help hold it in too.