Electrical Help - No lights, horn, etc. (1930)

[Mikeyworks]

(Long time lurker...first time caller )
Good morning, I recently purchased a 1930 Model A from an old friend that decided he couldn't care for it anymore.

I've chased down a few issues, but my lingering one is the electrical system.

The car drives and runs, but I don't believe it's charging.
I also don't have any functional electrical accessories (lights, horn, etc.).

I'm going to start chasing things with a multimeter, but I was wondering if anyone had any recommendations on where I should look in particular. I'm new to the Model A world!

Thanks!
Mike in MD

 

[Gary WA]

Start at battery work your way thru! One item at a time! Like oil? Do you have a fuse? Welcome to Ford Barn! There will be many suggestions coming!

 

[Tom Endy]

Start at the battery ground cable where it attaches to the frame. It is the most neglected electrical connection on a Model A. Remove the cable and sand the boss on the frame until it is bright shiny metal, Wire wheel both end of the cable.

Tom Endy

 

[dj]

check the wire at the generator thats what powers up the lights and horn
Dennis

 

[J Franklin]

Nice car, did you get any literature with the car? An owners manual gives lots of good info. I think it even has a wiring diagram.

 

[nkaminar]

All about the stock wiring is here: https://www.mafca.com/downloads/Seminars/2018%20Reno%20Electrical%20System%20Alex%20Janke.pdf

A most common change is the ignition switch wiring where a modern switch is wired to supply power to the coil. Another common change is the substitution of an alternator for the generator. And some cars have a 12 volt system with negative ground for the battery.

In addition to making sure the ground to the frame is good, add an additional ground to the engine, such as to a transmission bolt.

Use the DC voltage setting on your multi meter to measure the battery voltage when the car is off and when it is at a fast idle. You can measure the battery voltage at the lug on the starter switch and at a good ground point without having to take the floor boards out. For a 6 volt system the battery voltage should be about 6.3 volts with the engine off and about 7 volts with the engine at a fast idle. For a 12 volt system, double these numbers.

 

[Gary WA]

check the wire at the generator thats what powers up the lights and horn
Dennis

Also make sure that the two wires on the cutout if thats what you have is not touching the cut out needs a insulated washer between cut out and wires.

 

[Badpuppy]

Lights, horn and battery all connect at the same point on the cutout. You should get lights/horn without engine running. Check fuse on starter, if you have one. May be generator not charging or cutout not working. The ammeter will tell you if it's charging or not. Also generator begins to charge only when engine is well above idle speed.

 

[jrelliott]

If the vehicle has set for quite a while, you may need to polarize the generator. I would first do all the checks the others have suggested. If there are no shorts, polarize the generator and check to see if you get the car to charge at fast idle. The residual magnetism in the generator diminishes over time.

 

[Mikeyworks]

I appreciate the feedback team! Here’s my current wiring configuration as I got it when I got the car. I know it’s relatively simple and using the Model A bible really helps…
All of that said, I thought I would double down and show you what I currently have.

 

[Badpuppy]

Lights and horn are connected common with the battery (through ammeter) at the cutout and should work at all times. Check for blown bulbs and dirty horn button contact.

Wires on the cutoff switch appear too small for 6V starter. Safer to relocate to ground side (with larger cables).

 

[Rob Doe]

Mike, X2 on post #11. The car may be 12 volt - neg ground, which uses lighter gauge cables. If so, there are several different requirements, such as bulbs, starter and generator, wire positions at the ammeter, and coil, etc.

Please look under the floor mat and identify the battery and its connections as 6 volt positive ground or 12 volt negative ground and report back. You could remove the floor board and upload a picture of the battery.