Hi all, new to the boards here, I just purchased a 1951 F-3, and it has several electrical issues, not least of which is that it isn't charging. The truck is still 6 volt, and I was hoping that someone here might have a wiring diagram/schematic for her so I can chase out the charging and lighting systems. I am going to fully re-wire the truck and convert to 12 volt in the future, but for now due to funding issues I have to keep the old 6 volt system alive, so I'd love to hear any tips or tricks anyone might have. Any help would be appreciated, thanks!

 

Good grounds and thick battery cables will be your best friends. Clean all of the connections.

 

Here's some odds and ends you can tuck away for reference:

I imagine you're aware of the quirks of generators? They don't put out current below approx. 1200 rpms so if you've only had the truck at idle speed it won't charge.....

Also, generators require longer runs to bring the battery up to full charge.

Also, the gauges in these trucks are woefully inaccurate.

Don't tighten belts like modern trucks/cars. Keep 3/4 - 1" deflection in the belt like the shop manual shows. Too tight will result in bearing problems in the generator, waterpumps and fan hub.

 

This is a very useful site, with all the electrical schematics you want. Not specifically for an F-3, but I can't think what differences there would be. Don't forget, these are POSITIVE ground vehicles!!

Ford Flathead Engines - VanPelt Parts & Service

 

Another thing that jacks folks up with generators is that if they forget to polarize the generator when they replace the battery, then the generator will not charge the battery.

I believe you need to jumper a wire from the positive on the battery to the positive pole on the generator. Don't leave it connected, just brush it briefly.

I am sure someone will correct me if I am wrong.

 

Polarization on early flatheads was with a jumper wire but not on these. This model you disconnect the field wire at the regulator and briefly touch it to the batt connection on the regulator. Light blue spark. Then reconnect and you're good to go.

 

Thanks for the info everybody, it's been a very long time since i've dealt with 6 volt stuff, so I was feeling a bit rusty. After spending the afternoon under the hood the issue has been traced to a stone-dead generator AND voltage regulator. On further inspection it was discovered that the brushes in the gen were so worn they might as well have not even been there. Luckily I was able to source replacements for the gen and regulator locally and will be installing them later tonight, should take care of that.

 

if your brushes are that bad, then the gen bearings are due to be replaced. also, the commutator should be cut on lathe so that brushes make full contact. failure to do this will have you po,ed when it won't fully charge and eats up those new brushes. (just my 2 cents)

 

Are you replacing the brushes or the whole generator?

Is there a re-builder in your area?

I had a starter on my Harley go out and instead of paying $300 for a new one I had it rebuilt at a local shop for $75.

 

$130 here to rebuild the generator in my 52.