GM p30 PROBLEMS CRUISE CONTROL

[warrior90]

Hello Everybody

Winnebago, 6,2 L/Diesel , natural aspirated, P30 Chasis Year 1989/90

The Cruise Control does not work at all. I allready installed a new Vacuum Pump and new Vac Hoses. I have Vac on the system....also checked the air duct system..........and till here everything seems to be OK

Is there a check procedure or check list to trouble shoot the system, without driving the vehicle ?



Here are the pics.........









Yes this system is quiet old and I´m very
Anybody has an idear how to trouble shoot this mystery

Best Regards
Wolf

[87Rockwood]

Have you checked your brake light switch?

[warrior90]

Yes...........everything OK

Thanks for Your help......Since I allready did some research.....here some further considerations and questions with out answers:

What You see on pic Nº2 is the nob for MODE of CC in the center and the split part is for High and Low Beam. Pic Nº3 is the back of the transducer mounted on the engine. To orient You.......in the low right corner is the glow plug relais. The last pic is the inside of the transducer.

At this moment I´m trying to understand how this thing is working... wich means we have 2 electric components.........the switch for actuating the whole system and another switch related to the break pedal to deactivate the system. to that we have to add the mode knob and the set switch for memory.
All this together forms electrical signals that go to the transducer last pic., where we convert electrical signals to mecanical motion in form of vacuum. On the other side of the transducer we find a mecanical cable conduit going to the injection pump wich interacts with speedometer or transmission.
Eighter speedometer or transmision than confirm the electrical signal of the actuator /switch pic 1-2 by way of electrical signal to the transducer.

Breaking this down..........only one mecanic output of the transducer.....actuating on mecanic injection pump...........




but all other signals from and to the transducer are electric........so this is were the magic is happening..........since this is done by electrical wires.....each of this wires going in to the transducer come from a different component,.........actuator switch at steering wheel, breakswitch and speedometer/transmission.

If I got this correct so far, than each of the wires going to the transducer represent one of those components, wich should give us a posibility to check the components at the transducer for proper functioning.
On the other side hot wireing some of those wires should give us the posibility to override this components to see if the transducer works correct or gives us any reaction or reading.
On the pic of the transducer


Here a better pic see all the wires that go to the transducer............please also note the black and brown wires going to the other side of the transducer.
Also basics for manufactoring this unit,........there must be a proceedure for quality control.

That leads us to the following questions:
Who was the manufactorer of this system ?
How is it supposed to be serviced in case of failure ?
Is there any info on that in service manuals ....etc. ?

Also.... before I posted this thread on the forum.......... I did quiet some searching on the web and could find allmost nothing valuable.

So what is the mystery on this magic

Thanks for the help

Best Regards

Wolf

[Sprdtyf350]

Looks similar to the one I have.. Mine doesn't work either but i'm pretty sure you need to look for a box like the one in my picture. Mine had a blown fuse, maybe yours too..

[RubioRocket]

Has this resolved? I have a 91 Chieftain that sits on the same chassis. I had issues with he cruise control as well. Check the wiring running down he steering column. The wires on mine were small gauged and were crimped to connectors for larger wires. Re-seat and dab some dielectric grease on the tips of the male pins. The connector on my steering column is about half way down the column.

[warrior90]

Hello
and thanks for the reply.........to be honest, had no time to follow up on the subject due to other projects, but it is a question of time, because the problem has not dissapeared. Would be great and very helpfull if You Up Date Your adventure with the cruise control.
Do You have a wireing diagram for the CC............eaven that seems to be hard to come by.

Best Regards

[DAN L]

Originally Posted by warrior90

Hello
and thanks for the reply.........to be honest, had no time to follow up on the subject due to other projects, but it is a question of time, because the problem has not dissapeared. Would be great and very helpfull if You Up Date Your adventure with the cruise control.
Do You have a wireing diagram for the CC............eaven that seems to be hard to come by.

Best Regards

there is another current thread about cc problems on this site that i posted about the brake light/cruise control switch problem that i had.
for trouble shooting purposes, i built up the area on the brake actuating arm where the switch plunger rides with tape. that worked.
then i adjusted the switch about 1 1/2 turns longer.
i have more detailed posts in the archives of this forum.