Been trying to start my 1951 F1, but seem to get nowhere. I'm still 6 volt. I just installed new plugs (flathead V8) and charged the battery. What is happening is that the wires going into the starter relay are getting so hot that the rubber sheathing is literally melting when trying to start. I'm converting to 12 volt this weekend, but really wanted to go for a drive today. What could be the cause of the hot wires? Is this normal?

 

There could be several causes for this. The most common and first to check would be bad grounds and a faulty starter. On a 6 volt system especially, the grounds MUST be clean, bright, and tight. Any rust, corrosion, or looseness whatsoever can add enough resistance to the circuit to draw high current through the cables but leak off enough voltage to cause the starter to not turn. Bad brushes or windings in the starter can cause this also.

 

Another common cause is using too small gauge cables for the 6 volt system. They really need 1 or 2/0 gauge cable. Otherwise, they will indeed get very hot.

Edit: Here's a link with some useful info. https://www.ford-trucks.com/forums/1...hat-to-do.html

Keep in mind that converting from 6 volt to 12 volt takes some work. There's quite a few things that have to modified/changed. I left mine at 6 volts, but I don't live in a big urban area with loads of traffic, strangers (who won't help you push, lol), etc.

 

I wouldn't rule out a starter that is shorted in one of the coils.

 

Suppose the starter is bad. What is the best place I can get a new 12 volt starter from?

 

Makes sense. The PO rewired the truck. I also did not notice a fuse panel. Did these old F1s ever come with fuse panels?

 

No, they have / had two circuit breakers behind the dash, a 30 amp and a 15 amp. I highly recommend installing modern fuses if you plan to rewire the truck.

 

No, they have a circuit breaker that will switch off and back on automatically.

I'd look first at the size of the cables. If they look like standard 12V cables, they're half the size they need to be. 6V cables generally are close to 1/2" or 5/8" in cross-section (given that the insulation/sheathing varies) That's where po's usually screw up first.

You could always tow it up and down the road. You don't need the starter for that.

 

You didn't say which wires going into the relay are melting or if the engine is even cranking over but assuming that you are getting the engine to turn over and that it is the "big wires" that are getting hot and that you are not cranking on it for long periods of time, like ALBUQ F-1 my bet would be on the starter, most likely dirt or corrosion if it has been a while since the engine was last started. When was this engine last run or don't you know? I would not convert to 12v unless you solve the problem(s) as you could be compounding the issue(s) with more issues. Everything that everyone has recommended so far is good advice. Are you sure that you put the plug wires back on in the right order? That is a quick check. If you are not sure how they should go there is lots of good info on this forum on that. If you can't find it let us know and we will steer you to it. Don't jump to replacing parts unless those parts test bad. If you do it will cost you $$$ particularly if you have multiple problems which often happens.

These flathead engines are pretty forgiving due to their low compression. They run when something is wrong that would stop other engines. If it isn't starting it has to be something(s) pretty obvious.

Also, make sure that your gas tank has gas in it (don't ask me how I know this)

Good luck and let us know what happens.

 

Great advice. The truck ran a week ago just fine. I've got new cables and will clean up the connections first. Is the starter easy to remove and clean?

 

It's not a hard job, BUT it will fall apart on you if you're not careful. The two bolts that mount it to the bellhousing also hold the starter casing together. You'll have to put two nuts on the other ends of the bolts to keep it from coming apart on you. IF you are going to do that, go ahead and take it to a reputable starter/alternator shop and have them check it out. You asked a question yesterday about 6 volt vs. 12 volt on the starters. Most people who switch to 12 volt systems keep the 6 volt starters. They'll hold up as long as you don't crank on them forever with the 12 volt battery.

 

There have been a couple of threads here indicating fit problems with some of the new 6v starters. I'd recommned calling around your area to see if there is a carburetor/electric shop that rebuilds starters, generators, and alternators.

Most of those shops have gone away with the advent of rebuilt starters off the shelf at chain auto stores, but there are a few old timers still around who will actually repair yours for you.

Dan

 

It isn't difficult but it depends upon your experience and tools. If you run into trouble you know where to get help (pictures help). I would check your plug wires first though. Also there is some great guidance in the link that Doc sent to you (https://www.ford-trucks.com/forums/1070867-starter-dont-know-what-to-do.html. Start with the basics and work your way inside.

 

Replaced the 4 gauge cables with 2 gauge and it started right up! My truck has a heartbeat.

 

Good job! Feels (and sounds) great doesn't it.