Alwhite00

iTrader: (1)

using lt1swap.com instructions for modifying a 2000 truck harness - I have a #42 pin in the Blue PCM connector for fan but not sure if it is supplying a ground or 12v for the relay.

also #9 in the Red PCM connector for the fuel pump - Same deal - is this supplying ground or 12V?

Thanks

76larkman

pin 42 will go to a relay if you use a electric fan. relay will require you to run a ground. 12v positive from battery, your 42 wire, then wire from relay to fan(4 prong relay).-----pin 9 in red goes to fuel pump relay as signal wire. (4 prong relay)relay requires a ground, 12v positive from battery, your #9 signal wire and then a wire run to pump. I put fuse links in both fan and pump positives. Lt1Swap.com has you wiring fuses in the 4 place fuse block if you did as he did.

Alwhite00

iTrader: (1)

So they are both supplying voltage to trigger the relay, correct?

Thanks a bunch.

76larkman

yes both are trigger wires for relays. I run my grounds from relay to back of engine with other grounds as they all be same place. no searching for them later if together.

BP Automotive

iTrader: (3)

No. The PCM provides a ground signal for the fan relay and a positive signal for the fuel pump relay. Hope this helps!

Bill

76larkman

well thats how mine are and it runs fine, my wrong on fan, sorry.

Alwhite00

iTrader: (1)

Thank you.