PSI Conversion Harness hookup

[PunishedC10]

I have been reading for some time and trying to find some answers. I have a PSI Conversion harness for a ls1/4l80e. For the wires coming out of the bulkhead connector off of my '85 C10, which of these do I tie to the harness?
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The middle wire says I can run to the 12v on my harness. But I need to make sure it has 12v when the key is in the cranking position.

[Jstock85]

The middle should be all you need. The rest should be in the harness. but there are other cats on this board who know a lot more than me and can tell you for sure.

[PunishedC10]

Originally Posted by Jstock85

The middle should be all you need. The rest should be in the harness. but there are other cats on this board who know a lot more than me and can tell you for sure.

Thanks for the reply!

[PunishedC10]

The PSI harness came with one wire from the relay to run to a switched 12v for the ignition relay. It came with 2 pins to add a switched or constant 12v wire for the fuel pump and a wire from the relay to the fuel pump, should I the switched or constant 12v wire to the same wire as the 12v ignition?

[Jstock85]

again don't take me for the gospel but the fuel pump should get the 12v switch power

[mongocanfly]

I used psi on mine..I used my switched on hot wire that went to my distibutor for my switch on hot..then you need a constant hot as well and the grounds..simple..
The fuel pump runs out of the psi fuse block

[PunishedC10]

Originally Posted by mongocanfly

I used psi on mine..I used my switched on hot wire that went to my distibutor for my switch on hot..then you need a constant hot as well and the grounds..simple..
The fuel pump runs out of the psi fuse block

PSI ran a wire out of your block for the fuel pump? On mine, the 12v wire to the fuse block relay for the pump is not there, neither is the wire to run to my pump. No big deal, but by the time I run those two wires, the two for 12v constant and switched and all the wiring for two efans, I could have just rebuilt the original harness and bought a 4l60e to 4l80e adapter and saved alot of money for almost the same amount of work.
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[mongocanfly]

There's no wire for the pump...in the fuse block there's a terminal and a relay for the fuel pump..it should be in your instructions on how to wire it

[mongocanfly]

Like this..

[PunishedC10]

Originally Posted by mongocanfly

There's no wire for the pump...in the fuse block there's a terminal and a relay for the fuel pump..it should be in your instructions on how to wire it

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Yessir, I found those two in the instructions. Did you wire in a TCC switch ?

[mongocanfly]

No tcc on mine...I'm running a manual behind mine...

[PunishedC10]

Lucky you haha! I think I have it figured out now. I just need an extra fuse box so I can add two fuses for my efans. I only have one spare fuse slot in the PSI fuse panel.
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[cagodinez]

What are you guys doing for the temperature gauge? I can't decide if to drill and tap the passenger side head or water pump. I'm going to be running 91 suburban gauge cluster on my 78. I can't find the thread where a guy just re threads the stock sender, also does any one know a part number for the stock sender? Oh and sorry I wasn't trying to hijack I just figured since your all talking about ls swaps.

[PunishedC10]

Originally Posted by cagodinez

What are you guys doing for the temperature gauge? I can't decide if to drill and tap the passenger side head or water pump. I'm going to be running 91 suburban gauge cluster on my 78. I can't find the thread where a guy just re threads the stock sender, also does any one know a part number for the stock sender? Oh and sorry I wasn't trying to hijack I just figured since your all talking about ls swaps.

No worries man! I was wondering about the same thing haha
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[mongocanfly]

On your fans your gonna need relays..I used the psi relay setup on mine..not cheap but it works great..there's control wires for your fans in the harness..you just hook those to the relays along with constant and switched power..
On the temp sender I drilled and tapped pass side head. I'm running mech gauges in mine though...water pumps are very thin and can't take much force

[mongocanfly]

Here's the thread cago. ..http://www.67-72chevytrucks.com/vboa...d.php?t=726700

[Rich84]

I brought my sender to a local auto machine shop. No delivery charge $10.00

For the fans.. The junkyard is your friend. Factory fan (I used an Escalade) and relays with all the proper connectors $50.00.

[Jstock85]

yes to relays for fans also. I'm scared to drill into a head. I know I have it all jacked up!! Id def try the water pump. If it doesn't go well it won't cost as much to replace. just my op.

[PunishedC10]

I am using 98-02 fbody fans and wiring in my own relays. The radiator and radiator mount are for the big blocks. It's a 4 core I had rebuilt. Check out my build thread if you want to
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