OEM diesel 4k tach
 

I need to know how to use this OEM tach from a v8 diesel truck into my p pump cummins to throw a curveball. I have the entire cluster with wiring harness with power, ground and a brown wire that goes to an unknown location.

This is a real GM diesel tach and there is practically NO info on how to use it. The cluster was a mechanical speedo 85-87 gmc 7000 with the detroit.

Anyone here have any idea how to use this 8 cyl tach with a 6 cylinder 12 valve?

Thanks

http://i29.photobucket.com/albums/c2...psgtumub7e.jpg

Re: OEM diesel 4k tach
 

Is that tach electric or mechanical? If it is electric, you'll need to figure out if they used a 4 pulse signal or not like the gas tachs are. If that is the case, you machine 2 more grooves in your vibration dampener and use the dodge pick up sensor. You have to solder in a 1k ohm resistor in between the hot and ground wires of the signal wires for the pick up to work. Ive read of it being done on 4btswaps. I have not done it on mine but am going to someday.

Re: OEM diesel 4k tach
 

It's an electric one. Thanks for some direction. I'll try and find some more info.

Re: OEM diesel 4k tach
 

Was this tach from a 8.2 Detroit?

Re: OEM diesel 4k tach
 

That's exactly where it came from

Re: OEM diesel 4k tach
 

I can't remember where they picked up off those. It's been a long while since I had to work on one. :LOL: I'll keep looking and try to help you find the signal specs.