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When wiring that oil pressure relay, how do you wire it so the fuel pump runs when starting, or if you want to prime the fuel lines? Do you just have a bypass switch to force the pump on?

John Mc wrote: ↑Sat Nov 25, 2023 5:36 am When wiring that oil pressure relay, how do you wire it so the fuel pump runs when starting, or if you want to prime the fuel lines? Do you just have a bypass switch to force the pump on?

Since the carb has a float bowl I'm going to have a momentary switch just for priming. I was going to run a wire from the switched side of the starter relay but the way they're designed it's an almost impossible task as there's no relay.

Here is what I did. Need a 3-way key switch.

The correct pressure sender and safety switch is installed..
- Utilized the T that was already there.
- Removed the mechanical gauge and 4" nipple.
- Removed the OEM tubing to the (incorrect) sender.
- Put the switch in place of the flared tube
- Used a 1" long 1/8" MIP nipple to lower the sender due to the new PS hoses at the OEM height of the sender.
- Need to fab a custom clamp/bracket as it wasn't there.
Wiring now...
You would think for a big truck there would be more room. Surprisingly it's so tightly packed in there.

Fuel pump complete, need to dress the wires.

Had the chance to pick up a set of 315/85r16 MT tires. Need to mount 2 at a time cause I only have 2 jack stands.
New flaps and radial tubes with the new tires. Not quite the order in which I wanted to do things but when the deals show up one has to go with it.

No pictures till the wires are dressed and all tires are on.

Rdinatal wrote: ↑Tue Feb 20, 2024 2:16 pmwhen the deals show up one has to go with it

Tell me about it.
Good to know the work keeps ongoing.

Mounted the fuel priming switch.

Found that the spider harness that supplies 24v to the gauges was on it's last leg (pun intended). Easy enough to fab a new one. Also found an intermittent connection in the oil pressure wire. Now all the gauges are working! Still need to replace the temp gauge so all are new.

Next up is the signals.

Got the signals figured out. The mil flasher and controller were toast.. swapped them out for a Signal Stat 900 and a 3 pin LED compatible flasher. Previous owner had two wires active when the brake switch is closed which screwed up the stop lamps. Wired and labled!

Took off the old mechanical fuel pump to head off diaphragm cracks and resulting vacuum leaks. Made a block off plate. Removed the intake vacuum line to the pump (no pump now). Added a vacuum test port in its place.
Found a missing bolt where the intake and exhaust manifolds join. Don't know if that was a problem or future headache?
All manifold nuts to block studs real loose. Torqued to specs.

Revisited the brakes. Adjusted front and rear.

Raining here but the want to drive around the lake is tempting. A 1.5hr drive would be great at 80deg.

Next question:
There are AC Delco R45 plugs in it now. The previous owner used regular wires from the .mil distributor.

The points have been changed to the Pertronix module. Any suggested change in plugs or gap?

Pertronix units don't like copper plug wires, so if you use the stock mil wires, resistor plugs are required. Those are hard to find, tho.

PoW