ok, changed the psom....not working....so i guess ill try the vss

 

Did you try this as I posted earlier ????

Also, check that fuse #8 and fuse #16 are seated into the fuse holder (in the cab) snugly. A loose fuse in a fuse holder will cause intermittant power.

Also, IIRC there was a TSB about the screws in the dome light assembly that could be causing your symptoms.

Bob

 

I hate to say it, but....I told you the other day it was not the PSOM causing your problem.

I see in your other thread the VSS was bad, a new one fixed the problem.

Happy to see you got your issue resolved.

 

You were right should of done that first but got psom for free that's why I did that. Anyways still having a tranny problem its not shifting into the last gear and it does NOT have over drive. Is there a shifting sensor somewhere on tranny?

 

So you are saying the truck does not have an E4OD 4 speed automatic overdrive transmission? I know of very few trucks with C6s in this vintage. If that is the cause you have a completely different non-electrical related issue. The C6 transmission is 100% mechanical/vacuum controlled.

 

How can I tell for sure? The D does not have a square around it, also there is no off button on shifter. It IS an automatic

 

That is one tell-tale sign right there.

You should also verify if the transmission has 17 or 20 pan bolts. The C6 has 17. Also take a look at the shape of the pan. Use this for reference:

 

Ok I do know its 4x4. Let me go check

 

Its the C-6 for sure....but it looks like someone put a heater in it. What's that for?

 

I assume you are referring a transmission cooler?



or this version perhaps?

 

Nope its a heater....gotta 110 plug. Its in the bottom of the pan

 

Do you know where your truck came from/history ?????........general geographic area is o.k.
And is there a 110 plug somewhere near or on the engine block ?????

Bob

 

I have never heard of anyone putting a heater in a transmission pan. Engine oil pan, yes.

 

I have heard of it in engine oil pan but not transmission pan. What lines to I need to check to find out why its not shifting?

 

The C6 transmission is controlled by the vacuum modulator located on the side of the transmission and the linkage/cable attached to the throttle. I am not that familiar with this setup on this vintage truck. I would suggest to start with the basics, i.e. check the fluid level, verify the modulator has vacuum running to it and make sure the linkage is attached.