Upgrading your fuel pump? Don't forget to upgrade the power supply lead to handle the added amperage load. Higher pressure means higher current loads to pump the fuel. Adding a Racetronix.com hotwire heavy duty power supply relay harness to your fuel system is a very good way to provide the amperage and voltage your new pump needs.
Read the text at the bottom of the Grand National harness for a better explaination as to why this update is important to do.
Buick Grand National hotwire kit
Racetronix - FPWH-006 - G7 Fuel Pump Wiring Harness=
Universal hotwire kit
Racetronix - FPWH-009 - Universal Relay Power Harness=
1999-2002 Camaro harness may be a PnP setup but not sure
Racetronix - FPWH-001 - F99 Fuel Pump Wiring Harness=
The installation of this kit is very simple and should take no more than two hours in a 99-2007 classic. We did this conversion on DamnYankee's truck in my driveway and we were both impressed on how simple the install went. Be sure to have as little fuel in the tank as possible when adding the new harness.
I have only used the Buick harness so these instructions are more specific to it. The universal harness may work just as well, just haven't tried installing one, yet.I like the GN harness because it puts the relay at the tank, out of the way of prying eyes and keeps the clutter out from under the hood.
Tools needed:
---Floor jack and jackstands.
---Wire cutters
---Wire crimper/stripper
---15mm socket, 12" extension and ratchet wrench.
---heat gun (do not use a flame/lighter around the fuel tank!)
---5/16" nut driver or ratchet wrench and socket
Supplies needed:
---(2) heat shrink style butt crimp connectors, red.
---Black electrical or Black Gorilla duct-style tape
---small 18-20 gauge black wire, about 12"
---(1) red 18-20 gauge ring eyelet style connector with 3/16" hole
---Racetronix.com Grand National hotwire or Universal hotwire kit
http://www.ls1truck.com/upload/files/20/0827071802.jpg
Standard kit does not come with the extra ground cable shown.
Step 1: Disconnect the battery.
Step 2: chock both tires on the right side of the vehicle.
Step 3: Jack up the left side of the vehicle, front and rear, and place jackstands under the truck to support the weight.
Step 4: From under the vehicle, take a 5/16" nutdriver and loosen the hose clamp holding the fuel fill hose to the fuel tank.
Step 5: Remove the fuel vapor vent hose from the box on the evap canister at the front of the tank.
Step 6: Support the fuel cell with a floor, transmission or motorcycle jack. Use a piece of plywood to protect the plastic tank if using the floor jack or if your jack has sharp corners.
Step 7: Remove two 15mm bolts holding the fuel tank straps in place and then remove the straps. They come of the truck by just lifting them up in their slots on the driveshaft side of the tank.
Step 8: Slowly lower the fuel tank and watch for anything hanging up. It should low easily. The cell has a couple notches in the top of it that fit around parts of the frame. The filler hose will have a liner hose that slides into the fuel tank and it will slide out with a little help. Lower the cell until you have easy access the the pump wiring harness.
Step 9: Take the tape off the wiring on the LH 4-pin connector exposing the grey power wire to the fuel pump. The three wire connection is the wrong one, FYI. You can verify which one is correct by putting the power back to the battery, put a test light or multimeter on the connector the grey wire goes to and then cycle the key on. The lead should have power for a few seconds and then turn off. After verifying you have the correct lead, cycle the key off and disconnect the battery.
Step 10: Cut the grey wire about 3" from the tank connector or midway up the length of the harness from where the harness "Y"s off.
Step 11: Strip about 1/4" of insulation off both ends of the cut wire.
Step 12: Prep the Racetronix Grand National harness for use:
---1.) cut the red(fuel pump lead), grey(fuel pump signal) and small black(ground) wires off the weather-pack connector(flat style). NOTE: DO NOT CUT THE WIRES AT THE RELAY END! Once the wires are cut you should be able to toss the weatherpack connectors in the trash.
---2.) Add about 12" of additional wire and the ring type ground lug terminal to the black ground lead.
---3.) Crimp one of the red butt connectors to the red lead and one butt connector to the grey lead
Step 13: Back at the truck, crimp the grey wire from the wiring harness opposite the fuel tank to the grey lead from the relay.
Step 14: Crimp the grey wire from the fuel pump connector to the red lead from the relay.
Step 15: Take the heat gun and shrink the heat shrink tubing down on the butt connectors.
Step 15: Connect the ground lead to a point on the frame. I use the same location the ground strap from the filler neck connects to the frame.
Step 16: Tape the leads going to the fuel pump back up. Tape the relay to the wiring harness. I prefer the black Gorilla tape for this operation.
Step 17: Reinstall fuel tank in reverse order of removal and remove jack.
Step 18: Reconnect the EVAP hose
Step 19: Route the power lead to the engine compartment following the original pump harness, use supplied zip ties to hold in place. Find a location to bundle the excess wiring up under the frame/cab area. You can shorten the lead if you like, Orielly has large gauge crimp connectors behind their counter that they sell by the piece for the main power lead if you decide to go that route.
Step 20: Connect the fused power lead to the alternator lug and find a suitable method to secure the fuse.
Step 21: Finish zip-tieing up the wires and any excess out of the way of heat and sharp edges.
Step 22: Remove vehicle from jack stands and remove wheel chocks.
Step 23: Connect the battery and start the vehicle.
Congrats, you're finished and now have a much better voltage supply for your fuel system.
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Originally Posted by RedHeartbeat
Slowest in Oklahoma...