ls swap water temp & fuel guage problem

[ncnichol]

so ive swaped a 2002 4.8 out of a p/u into a 98 p/u. i used all the 2002 pcm, harness & uhfb. started the truck today & all went well except the temp & fuel gauges dont work {kinda figured} i was going to put the 98 water sending unit in the pass side head and be simple but it doesnt come close to fitting in that little hole in the ls head so i teed the wire into the ls sender wire....doesnt work. next the fuel gauge just reads over full. i see the 2002 circuit has the sender ground returning to the pcm but in 98 it grounds to the frame, i left it grounded to the frame. i also read to move the sender sig to a new pin in the red pcm plug pin 38. i did this but my programer couldnt see how to program that so i put it back to the original pin. no luck. any info on this would be great. thanks guys.

 

[GaryCCR]

You have to tap the head to get your old temp sensor to fit. I'm using a 98-02 camaro v6 temp sensor in mine.

 

[ncnichol]

You have to tap the head to get your old temp sensor to fit. I'm using a 98-02 camaro v6 temp sensor in mine.

 

[ncnichol]

So i just watched a video on utube. Great solution, you use a stock water temp sender from a 98 camaro with the LS1. Goes in the stock location on the drivers side head. This is a 3 wire sender. Just cut off the 2 wire plug and hook the 2 top wires, gray to gray, black to yellow. That takes care off the computer then hook the third wire to the 98 truck green gauge wire. Easy peasy as they say. Thanks for your post.