Searching for a short?

[wartmeister]

Got it all. Will get back in a week or so.

Cable from the solenoid to the starter is brand new, but I guess that doesn't mean a lot these days. It's also 4 feet long because I had to route it away and around the headers. It looks like it is in new condition, still.

[wartmeister]

1. I hot wired the battery to the starter and got the same click of death. I then tightened the starter lead and ground and got it to turn over and was able to start the engine several times. Conclusion: Starter eliminated as the problem.

2. I took the opportunity to do some more troubleshooting with the engine on... The dash voltmeter showed full deflection 12+V when the engine was in advanced rpm with the manual choke engaged. When I reduced choke and let the rpm back down to normal idle range, the voltage dropped to 5-6V. When I revved the engine, the voltmeter goes to 12, but goes right back down to 5-6V as soon as I let off the gas. As you said before, something is drawing heavy on the electrical system...a short somewhere.

3. Several questions about running each wire.
a. I pulled each fuse and noted that the voltmeter didn't budge/increase when any of them were removed. Can I conclude that all the associated systems can be eliminated as a cause?
b. If a particular system works properly...like the radio, can I eliminate that system.
c. Any idea what the most likely culprits are, so I can start there?
d. Can you give me an example how to check a wire...say the cigarette lighter? Where do i put the red voltmeter lead? The reason I say cigarette lighter is this all happened the first time I used the cigarette lighter to power a small GPS.

[wartmeister]

Progress note:
Assuming starter is not the problem, so did some trouble shooting beginning with the ignition switch.

Ignition Switch (2).jpg

The center post is to Accessories. Voltmeter: 12.5 V on the post with the key in the on position.
Red is battery voltage in, Purple is ignition, Pink is solenoid.
The Red wire was 12.5V coming in...I conclude there is no problem between the battery and ignition switch.

The brown/tan lead goes to the Brake warning light and has a lead from the pressure switch on the brake reservoir. When the pressure switch senses pressure differential, it closes the circuit and the light comes on. Particular to Ford truck.
in any case, this is the strange part...if I disconnect the brown lead and put the voltmeter to it, it reads 5.2V? You would think that it shouldn't have any current on it...it goes to the warning bulb with a wire going on to the pressure switch. I don't think its a coincidence that 5.2V is what might dash voltmeter reads when the key is on. Voltmeter applied to the brake warning light connection on the ignition switch is zero.

Does this create any clarity?

[wartmeister]

More information regarding the tan brake warning wire.

Brake Warning connector (2).jpg

At the top, the two tan wires...one comes from the ignition switch and the other goes to the brake pressure switch. The pink is battery-in. The actual light is on the other end of the connector.

OK, the battery-in line reads 12.5V. The tan lines read 5.2V. The bulb is in-between.

Electrical wiring for dummies question: Does the voltage drop because of the bulb resistance? If so, then the problem isn't here and i need to keep looking.

[wartmeister]

Last report. I am able to start the truck now...suspect the starter wasn't grounded quite good enough. The mount bolts were tight, but I tightened them some more. Also believe the dash voltmeter stopped working properly. It reads 12V across the terminals, but 5V on the gauge. Burned up the fuel gauge while testing (didn't have the voltage regulator grounded!). In any case, I have another issue that I will bring up under another string.

Thanks to all for inputs!

[67 short box]

im sure im wasting your time, but your ground strap from the motor to firewall is all good? we put head gaskets on a 460 once and didn't connect it back. it would do all kinds of weird things without it. spin over and not start, next time would not stop with key, then just click, ect….
just a thought

[67 short box]

sorry, missed last post

[wartmeister]

Turned out the voltmeter was good, too. It was an ammeter that had been modified to be a voltmeter. A little below half equates to 12.5V so it was OK. Appreciate the thought on the motor to body firewall ground strap, but I made sure it was solid metal on metal. I might have had a problem with the ground on the starter itself...hard to say for sure what did the trick. Now I can drive, but all the shows are cancelled. Doh!