I set up a relay to supply the choke with 12 volts and thought about setting one up for the fuel pump too. However, I’ve already got 14 gauge wire and battery voltage going to the pump on both the main and bypass circuits and both circuits are protected with fuse holders. The little cube pump ran on 3 amp fuses but the new quick fuel pump blew them instantly along with the 5 amp fuses i tried next. Currently it’s running on 7.5 amp fuses and i’ve got about 100 miles on them but with 14 gauge wire I recon i could still safely step up to 10 amps if necessary.

Otherwise I may need to remount the pump on rubber shock mounts or insulators because it’s pretty loud like i have it now bolted directly to the frame rail.

 

You could just parallel the choke with the fuel pump. If you have oil pressure, fuel pump runs. If you don't, the fuel pump doesn't run. You want the choke to work the same way. This would be a simple solution but would have one little problem. The fuel pump is powered during cranking. If the engine cranks right up, no problem with the choke being hooked with the pump. If the engine was stubborn and you keep cranking and cranking and messing around with it, the choke might start to pull off. Not sure if would be a real problem though.

 

As you found out that new pump draws more power / amps than the old one and why you want to use a relay as it will send more power to the pump.
I bet if you were to check the amps at the pump it might be even a little higher.
You could maybe run 12 ga wire as a cruch and the power drop would not be as bad.
Dave ----

 

The instructions that came with the pump said it would draw 5 amps so I’m not surprised it popped a 5 amp fuse. Otherwise the 7.5 amp fuses are holding while i make more miles. Should I just run 10 amp fuses now for a wider margin?

To run full voltage to the new carb ! used the factory choke wire as the signal wire when i set up the relay. As for the fuel pump, it came from the factory on a relay. The key on signal (or trigger) wire to the fuel pump relay is controlled by the oil pressure switch. The power wire is hot all the time to the fuel pump relay. It comes straight off the big hot lug of the starter solenoid, through the inertia switch, to the fuel pump relay. There it quietly waits for the signal to come through the oil pressure switch to close the relay switch and complete the circuit to the fuel pump. HOWEVER, there’s a resistor wire down stream in the factory wiring that reduces the voltage to the stock fuel pump(s). So when I installed the cube pump I cut the power wire coming off the relay (before it could get buried in the wiring harness) and ran a new wire straight back to the external pump.

That said, I found these really cool fused relays when I did the choke. They’re rated for 30 amp fuses, but I’m only running 10 as per the carb instructions. Anyway, I could definitely see swapping out the stock fuel pump relay with one of these fused relays. Doing away with the fuse holders I’m running in my wiring now would certainly clean things up. .

I did the AC. It’s done. I watched enough you tubes and went for it. I rented the manifold and vacuum vacuum pump from O’Reilleys and spent a long day fussing over PAG oil. where to put it and how much. The compressor, bottle of pag 46, o rings, and expansion valve all came as a kit. Tragedy averted when i managed to extract a broken Schrader valve.

Bad vibrations: See the tall bracket with the slider? that attaches to the AC. The sturdy base the AC sits on also has 2 sliders, and since I was able to achieve good belt tension with them I left the tall bracket off to allow more room for the AC filling process. Naturally I left if off for the first test drive and wouldn’t you know it. A weird vibration when decelerating from 1,500 to 1,000 rpm rolling to a stop. I could feel it in the brake pedal. Reinstalled tall bracket, no vibration.

Changed the oil and installed the cruise control today. Now all of my parts totes are empty.

Tech tip. Those ratcheting blue cutters are for plastic pipe. But they are also excellent for cutting rubber hose. My go to for radiator, heater, fuel, transmission, vacuum line, Nice, clean, cuts. .

 

I was always taught that fuses are for protecting the wire, not the device connected to it. 14g wire is rated for 15 amps, so you're fine with anything up to that.

 

Originally you also had a wire coming off the small "I" terminal of the starter relay, feeding the pump also. This runs the pump during cranking only. So you do not have to crank and crank, waiting for the oil pressure to build up from the starter turning the engine. If you just rebuilt the carb, or the truck has sat a long time and the carb is dry, just running the pump with the oil pressure activated relay can take a lot of cranking.

 

When I converted my truck to an electric fuel pump, I also added a momentary toggle switch to bypass the oil pressure switch. As the truck often sits unused for days at a time, the fuel evaporates from the carb. I simply hold the momentary switch for 5-10 seconds to replenish the carb's float chamber before hitting the starter. The engine fires right up with no extra wear and tear on the starter. I highly recommend this simple mod.