So I have a 66 F100, thanks to the awesome people on this site I got my battery issue fixed. So to start our I will say right now that this truck was running with the battery cable on backwards, this came thru confusion of color wires and well just a mess, So i understand I might have some issues so I am looking to hammer them out as I go. So here we go. The battery and connection issues have been fixed. So I installed a new volt gauge due to the previous one melting. Here is my new issue. I get in the truck to start it, with the key in the on position it reads 12-14 volts on the gauge, but no lights or anything, the truck doesnt crank either. I tested the battery and got 12.4 volts, i tested from battery to started solenoid and it reads 12.3v now i check the connections from the solenoid to starter with the key turned to start and get 0v, I am able to bypass the solenoid with a screwdriver and get the motor to crank, my determination is a faulty solenoid, i bought one, but havent replaced it yet, i still have no lights on in the truck when set to on, the weird part is the volt gauge will read zero with the truck completely off, but if i pull the headlight switch the gauge reads 12-14v, but the headlights dont ever come on, and goes back to zero when i turn the lights switch off, so apparently the switch is getting power, and all the fuses are ok none are blown, unless their are more fuses then the ones under the dash. so dam confusing!!! someone mentioned voltage regulator but idk what that even does or how to check it, so what can i check next? where do i need to go from here? I have a volt meter and ready to dive in, but I really dont know what to check next since i get nothing when i turn the key, please if someone can help Im so lost when it comes to electrical, im trying to get this running for my step son it was a gift from his grandpa, but it was a really neglected truck it basically sat for 5 years. any help would be appreciated. thank you

 

Some people do not pay attention when replacing the battery. They buy an AMC/GM/Chryco battery that has the terminals reversed.

Then they unknowingly hook the battery up backwards and wonder why the amp gauge needle shows a discharge, or the amp idiot light comes on and stays on.

 

Hi again. Are you saying you get no headlights even without the key in the ignition?

And based on your other topic (the one with the photos):

1) You now have the red cable hooked to the +battery terminal going to the +solenoid, and the black cable hooked to the -battery terminal and going to the engine block down by the alternator?

2) These connections are all tight and clean?

 

That is correct, no light even with no key at all. I have not changed the wires. According to the pics I have connected the black to the + terminal that connects to the solenoid. The red is still connected to the block and connected to the - terminal. I have not switched them but will after I narrow down the issue. Yes all connections are good and tight.

 

My battery is turned around from yours, but it doesn't matter as long as the POS and NEG are correct from the battery.

Make sure the cables go this way: The POS cable goes from the alternator to the front of the solenoid then a RED battery cable from the front terminal on the solenoid POS terminal then to the battery terminal.

NOTE: there is a connection that goes to the lights and other components from the front solenoid connection, POS.

The NEG cable goes from the NEG battery terminal to the block. Make sure the engine is grounded to the firewall with a ground wire.

The rear cable from the solenoid goes to the starter. It doesn't matter what color the cable is as long as it fits. Mine is a black cable which I think is the correct color.

On the solenoid there are 2 smaller wires that plug into the solenoid. On mine the front one is RED, make sure they are not mixed up. if the wires are correct try this to see if the solenoid is bad, pull the front small wire off and jump the little terminal with a screwdriver to the big terminal on the solenoid, this should spin the starter. Make sure it's in park or neutral. This is one of the old ways thieves would hot wire a ford they use this method to start without a key.

Assuming your alternator is wired correctly and the regulator is working it should fire up. If I remember correctly it should start and run with a bad regulator but it won't charge. It may be prudent to replace the regulator anyway so you don't get stuck on the road at a later date.

Fords used to be POSITIVE GROUND years ago, I think they switched to NEGATIVE GROUND sometime in the 50's if I remember correctly. I'm sure another member may be more familiar with the exact year. Some models of Ford's had alternators starting in 63 and I think by 64 they were all equipped with alternators but I'm going by the T-Birds, 63 and up.

It's not fun to chase down electrical problems and if you have one wire where it shouldn't be you release a lot of smelly smoke.

Hope that works for you, good luck.

 

Larry he needs to jump the solenoid small terminal to the battery pos. not to the starter. If it cranks the solenoid is fine, it should be fine reversed polarity on a coil makes no difference as long as one end is ground and the other coil end is positive it will work, headlight switch sounds like a chassis ground, headlights get there ground from the body, he might want to run a couple 10ga from the negative to the fender well.

 

That's right, I had another senior moment
I fixed it!
Thanks form catching that blunder.

It wouldn't be a bad idea to add a ground cable from the frame to the bed also.

 

Ford went to negative ground in 1956, previous years were positive ground.

1963 Thunderbird was the first FoMoCo vehicle to come w/an alternator as standard equipment.

All the other FoMoCo vehicles came standard equipment w/an alternator beginning in model year 1965 (1965 Mustang's from 8/17/1964).

 

On my 64 t-bird, when the solenoid went (and I went through a couple until I replaced everything in the starting/charging system), I had exactly the same symptoms--no lights or power.

Put the new solenoid in and perhaps carry a spare. I never tore one of these apart, but I suspect when it blew, there was a dead short in the solenoid somewhere.

Different platform, but similar system. Here's the whole story: Vintage Thunderbird Club International ? View topic - 64 is eating starter solenoids

~Steve

 

I don't see how the truck would be different from my Mustang. Once by mistake put a 24F in the Mustang. Took a whole 5 seconds to realize something was wrong the moment a wire off the solenoid started to melt the insulation. Then I realize a 24F had the terminals reversed.

 

check your fuseable links, I believe they are yellow wires. You probably melted them when you reversed the batt connections.
I don't have a diagram in front of me, they may be black with a yellow tracer.