So I picked up a 55 f100 project and I am trying to sort out some of it's major problems. When I picked it up from the previous owner he stated the truck would start if some gas was dumped down the carb, so once i got home and threw a 6 volt battery on it ( positive ground) and I could get it to sparticly turn over and indeed got it to run for a few seconds on the gas that was dumped down the carb. So I assumed i had a fuel issue and an electrical issue (since I could not always get the starter to turn over). My fuel issue seems simple enough as once I pulled the pump apart there was a tear in the diaphragm, so i moved onto my electrical issue.... I started looking over the system and my first assumption was the starter solenoid since I could not even hear a click from it the times that I could not get the engine to turn over, but after looking at the solenoid I noticed it was a 12 volt unit which seemed strange but I replaced with a similar 12 volt unit anyway. Now I can get the solenoid to click every time I press the starter button but the truck never turns over... Once in the while when I press the starter button I also get a whining noise but I am not sure where it is coming from. Hooked everything up the same way I took apart, so why would it not turn over now? I have also been looking over some of the other parts of the electrical system and noticed there is a 12 volt coil installed with some type of box mounted next to it that I have never seen on a truck like this before so I'm not sure what it is... The generator does not have a tag on it so I am not sure if it is 6 or 12 volt, how can you tell them apart? I pulled a couple of light bulbs that I could get at easily to see if they were marked but none were... All of the front body panels of the truck are removed and the grille and headlights that came with the truck are off of a 56 so they should be 12 volts anyway so I cannot use them as an indicator. Any help on sorting out the electrical would be appreciated, I have never really messed with electrical systems and in general not a huge fan of working with electrical but I see this truck is going to test my electrical knowledge/abilities, and probably the knowlege/abilities of the others that I have helping me.
Test the bulbs on the 6 volt battery. If they are 12v, they will be barely glowing. I don't know if a 55 was 6 or 12 Start there, first. IMO
55 was the last year of the 6 volt system for Ford f100's (and i believe Ford in general), 56 started 12 volts.
Sometimes it's just easier to start over. Lots of $100+/- wiring kits out there to accomplish what you need. OR start with one wire and trace it from the point of origin to the point of termination. Meaning if it's for a starter/ignition switch go from the solenoid to the starter button or key switch. Make sure all the connections are cleand and tight. The starter needs a good solid Ground and make sure the terminals and the wires are fresh. Throw the old stuff away and start over when is comes to battery connections and the chasis grounds. This will ensure the starter will spin fast enough to start the truck 6 or 12 V and the light will be bright as they can be. If you think of electrical like this it'll make it easier. Comes out of the power source wether it be the wall or the battery down the lines like water to a resistor/use spot and back to the ground. This makes no difference wether it's your house or a car positive or negative ground. The difference is AC or DC but we don't need to get into that. Be patient and it'll pay off don't just start cutting wires unless you are going to replace them all. If somebody did make the truck 12V then go with it you'll be happier in the long run. But if it's 6 still it'll be just fine for now. Good luck and have fun, Tim
Like TERPU said above, you might be better off to get a basic kit and rewire the thing - I did that on mine and learned a ton in the process. The extra cost might prevent break downs later on the road... Good luck! Post us a pic of your project!!
There is nothing more fun than trying to figure out an electrical system that someone modified. If it has a 6 volt starter it will turn faster on 12 volt but you need to isolate the starter from anything that 12 volt could damage. On Ford starting systems, the first thing to check is cable connection at the starter. There are a number of solenoids that look like the regular Ford type but they can be wired differently. Some have one side of the solenoid coil powered by the battery cable and the other terminal has to be grounded through a starter button. Look at the voltage regulator and Generator for anything stamped into the case that might be a clue as to voltage.
That stuff drives me so crazy I'd rather tear it out and do it all myself from scratch. It's cleaner, easier, and cheaper. Last universal kit I bought was under $100 for 12 fuse block with relays, flasher, and wiring harness. Took me a day to wire it in, and I'd probably be troubleshooting crap wiring for 4 days!
when you look at the coil, which side is the small distributor wire going to? seams strange that someone would use a 12v solenoid and coil if it wasn't converted to 12v's.
When I come up against a mess like that I start over and make a new harness by wiring, testing and trouble shooting one circuit at a time (ignition, lighting, etc...) All the while, I route the wires together keeping everything neat so it's a nice clean harness when done. Everything gets labled along the way so later there is no problems adding stuff or trouble shooting. Otherwise it'd drive me nuts...
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