So I had asked a few weeks ago about using the good (but old and small) pump to drain the gas in the tank before I install the new upgraded racetronix set up. Couple people mentioned jumping the relay which in theory sounded like a simple plan. Now I'm actually ready to to it, but I admit, I don't actually know HOW to do it. I haven't looked at the actual relay too close yet. Do I need to use a clip like the ALDL jumper? A piece of wire to make the jumper? ....which wires am I jumping to bypass the relay?

FWIW - the entire pump set up is being replaced, wires and all. Racetronix hotwire kit/harness and Holley HP EFI. Gonna be all new. BUT....at this moment, it still sits bone stock.

 

Just jump the pump at the ALDL connector. Jump from +12 volt source to the fuel pump test pin at the ALDL connector. You won't need to have the key "on" provided you don't use an ignition source for the +12 volts. Here's a diagram of the ALDL connector. HTH!

 

Well that's pretty easy!

 

Just an FYI, you need the fuel pump relay present to pass the power from the ALDL terminal to the pump (normally closed contact on the relay). Here is a diagram showing the wiring. GL!

 

So I'm a novice at best when it comes to electrical. From the diagram, I see the red "fuel pump prime connector. Is that what connects to the ALDL port?

 

Yep, pin G on the ALDL connector. GL!

 

And for those not running a factory harness anymore all you'd need is to run a 12v source to the tan wire on the relay plug. That should feed the pump 12 volts and kick it off.

I don't have a factory harness anymore but I still have the relay wiring in place, and I'm using the LT1 Fuel Pump signal wire to drive the relay. Much like the stock TPI setup.

 

Thanks Bigal55.

...as for the Harness, I'm going to completely replace the factory wiring with Racetronix hotwire harness, and it'll be controlled by the Holley HP. Pretty straightforward. I think I'll wire in a crash switch/sensor too....but you get the idea.

 

I also need to drain old fuel from my tank. I want to make sure I understand this procedure correctly so as not to fry my Bosch fuel pump.
1. Connect lead from "Red" terminal on relay to the "G" on the aldl connector?
Do I also need to run 12v to the "G" terminal on the aldl?

Thanks

 

My understanding is ANY 12v source to the "G" terminal. ....the relay just needs to be in place to pass power to the pump. Without it, the "G" terminal doesn't go to the pump. It's not that you're getting power FROM the relay TO the "G". Rather Power to the "G", passes through the relay, and on to the pump.

 

Just drained the tank. OMG. Stupid easy!!!!!!!!!!

 

awww i was so looking forward to doing this right now, then I found the pin not there.

 

On some gm relays there is a red pigtail that can be powered up to bypass the relay.

 

Or power to pin e of the relay

 

Im looking at the wiring diagram, comparing to the truck relay. The trucks use labels such as 30, 85, 87, 87a, 86, 30. And the diagram on the relay has 30 constant power (grey), and 87(red)/87a switched.
So if red is going to the fuel pump then cool.

 

Wasnt red. Grey/orange is the way to go.