Jseal52

I’m looking for where I can tie my electric fan relay into my ignition source in the fuse box? So that they don’t have power tell I turn my key on.
Also looking for a good source to power my afr and boost gauges in the cab. Preferably from the fuse box in the cab.
2003 gmc rcsb
Thank you

FFDP

iTrader: (2)

I always had to use power sources from the underhood fuse box because those were switched power sources. Atleast in my 2006 and 2012 trucks. I always use the radio fuse with an add-a-circuit and one of the o2 sensor circuits or similar.

The interior fuse block on the drivers side when only using a 10amp fuse, they were always power on even when the key was out.

Jseal52

My truck is a 2003 rcsb guess I shoulda put that in there.

madmann26

iTrader: (7)

For the gauges, get some mini-taps from Amazon.

Jseal52

Where do you hook it into?

MikeGyver

iTrader: (5)

You should be able to supply power to the relays full time if you are using the PCM with also maybe the A/C clutch to trigger the relays. Even if you are using an added on temperature control, the power for the fan relays doesn't need to be switched, only the power for the control wire needs switching.

Jseal52

That’s how I have it hook up right now. Just trying to find out where I can put my control wires for the thermostat to run the fan relays. I have the three relays tied together and just need to hook up the control wiring from the thermostat that runs the relays for the fans. Don’t want to wire into my pcm.

madmann26

iTrader: (7)

Mini-taps piggy back onto an existing fuse that is on when KO.

10 Pack - EPAuto 12V Car Add-a-circuit Fuse TAP Adapter Mini ATM APM Blade Fuse Holder