1966 C10 with an electrical gremlin- help

[TxGoats]

Howdy folks, long time member but I’ve been away a few years. I picked up a ‘66 C10 that had been sitting many years. Have it running great with a 350 Crate motor, new bed, suspension, cab seals, body mounts, new seat cover and flooring. It’s mostly rust free except the driver door rocker. I love it, I have also restored the old Clardy Jet Star under dash air but I have an electrical gremlin I can’t figure out. Here are the particulars:
63 amp one wire alternator
New battery, ignition switch, restored wiring from ignition to starter, new ground straps, new cables.
Issues:
Starter will intermittently not start regardless if it’s hot or cold when starting but will always start with a remote starter.
Voltage shows 14 volts at the fuse box when started and alternator excited but when I turn on my headlights it drops to 11.3 volts but the battery doesn’t drop but maybe a tenth of a volt and turning on the ac is worse. I’ve disconnected each fuse and no changes, disconnected the wiring to the back lights, no change.
Any idea where to go from here? Time to just rewire this old guy?
Thanks for any helpful advise.

[64 K10 Stepside Guy]

If it does crank slow or at least tries to turn, then the battery - although new - does not have the capacity to turn the engine and you should check the capacity of the battery - not just the voltage. Maybe missing water if not maintenance free...
If it does not do anything, check the ground wire and the wire to the starter - incl. connections to the battery. If the voltage drops to 11,3 when the engine is running, it would be the regulator to check.
If you pull all fuses without changing the situation, the wiring should not be the issue.

[TxGoats]

Starter cranks strong so battery is good. With the engine off and turning headlights on I get a drop from 12.3 volts to 9.3, same with the blower on the air conditioner. Battery voltage shows almost zero change when lights are turned on and engine is running it only effects the voltage at the fuse box. Thanks for your input

[bonehead]

Those types of problems are usually caused by poor or missing grounds. Make sure you have three solid grounds: engine to frame, frame to body, battery neg to body. Check them out first. Good luck, BH

[DPowers]

Run a hot wire from battery to the horn relay. Should take care of the intermittent no start.

[bhap]

Check out Madelectrical.com. They have an improved wiring diagram that will give you some good ideas for configuring relays for headlights and other big users of electricity. I would also check the connections in the fuse bix - are they clean or crusty? When I redid my wiring, I kept most of the stock connections, but used headlight switch to power a relay at a fron distribution bar so headlight switch only carried minimal amps - only enough to trigger relay.

[TxGoats]

Originally Posted by bhap

Check out Madelectrical.com. They have an improved wiring diagram that will give you some good ideas for configuring relays for headlights and other big users of electricity. I would also check the connections in the fuse bix - are they clean or crusty? When I redid my wiring, I kept most of the stock connections, but used headlight switch to power a relay at a fron distribution bar so headlight switch only carried minimal amps - only enough to trigger relay.

Thanks, this is probably my best solution. Thanks for the info.

[franken]

It sounds like you're describing a click or nothing from the solenoid issue w/o saying so. You might provide a description of what's happening.
Measure the voltage to ground from the solenoid S-terminal with the key in the start position when the problem happens.
Fixing a headlight issue won't solve a starter or solenoid issue.

[TxGoats]

The ignition switch does 3 things. Starts, clicks but continued tries and it will start dropping voltage to about 10 volts or it does nothing and volts drop off the gauge. In both cases when it clicks, I can hit the remote start, which is connected via clips to the starter, and it starts, same when there is nothing when I turn the key. The starter always works with the remote starter that’s why I ruled out solenoid issues.

[pdxhall]

Try checking the ignition switch. I had to change mine.