Hey guys just curious if anyone could help me out with testing my crank sensor and pcm. I recenlty had the batteries out of my truck for a few days to change the rad thermostat and block heater when i finished up i went to jump her and now ive got not tach no speedo the trans wont shift normally and no od lock up and the alternator doesnt seem to be charging. Ive read alot that the cps (crank position sensor) is notorious for causing these issues but have no way to test without forking over the hundred for a new sensor Up front. I have a decent multimeter but dont know how to test the sensor. Shes a 96 2500hd 12 valve cclb little help would be greatly appreciated

 

I've never done this myself, but I found an article that might help:

Part 5 -The Basics of Crank and Cam Sensors and How to Test Them

Hopefully someone with more experience than I will jump in. Good luck!

 

thanks ill take a look. im nervous because most times ive seen people comment about crank sensor issues they talk about sporadic tach and speedos but mine just completely dead the oil pressure gauge seems to be working and the temp sensor and fuel gauge seems fine. oh and the o/d off switch no longer lights up when depressed.

 

I do not believe there is a crank sensor... the small "sensor" at the crank is a magnetic pickup that runs the tachometer.... should be set at around .052 clearance from the vibration dampner... all it does is send a signal to make your tach know the engine speed...