2nd Gen Non-Engine/Transmission 98 12 valve electrical problem

[Skydiver]

Need help,

Any ideas as to why this truck does the following.

Tach, alternater, transmission (Will not shift) & the Air cond. compressor stop working all at the same time, then they all start working fine. Seems to do this more in the morning.

Truck is:4x4 auto with 175k.

Thanks Tim

 

[jtwcummins]

They are all controlled by the PCM, computer. I would remove the 3 connectors on the PCM and used contact cleaner then plug back in. I have found the major cause of intermittent electrical problems on new vehicles is connectors and grounds.



Forgot this, could make problems worse if you don't:



Make sure the batteries are disconnected. If possible use diaelectric grease on connectors when plugging back in.

 

[vssman]

I agree with Jay. Make sure the PCM plugs have a god connection. Mine stop charging after I slightly moved the center connector. Removed the plug and plugged it back in and it was back to normal.

 

[Skydiver]

We tried cleaning the PCM connectors. No help.

.

What we have found to help is cleaning the crank angle sensor.

What are the symptoms of a failing crank angle sensor?

Also will the crank angle sensor give intermittent problems or will it stop working all together?

Thanks again Tim

 

[vssman]

The crank sensor tells the PCM that the truck is running. Check the gap - I'm not sure what it should be but probably something like . 060 set with a brass feeler gauge.

 

[Skydiver]

Latest news!

Since we took a hammer to it (crank sensor)we have had no more problems. It's fixed. No kidding!

Thanks for the replys.

Tim