The B.B. in the title represents that this is from the archive of the late Bill Bently, who ran a flathead Q&A informational site before he passed away. All threads from this source will be titled using the B.B. identifier on this site. We’re archiving some of the threads, so that his work is not lost or forgotten and so they will continue to educate flathead enthusiasts for years to come.

TomG (Jan 1 2000 2:54PM) Charging system
Hello, I hope someone can help me. I’ve got a ’52 239 that’s been converted to a twelve volt generator system. I got to drive it about twenty miles today. This is the longest trip since I got it running. About ten miles into my trip, it started to miss and run rough. I noticed that my new amp gauge was showing a reading of ‘O’, right in middle .How do I find out what is causing the problem? I think the charging system is failing somewhere. I need to know were to start looking for the problem.

Rumble seat (Jan 1 2000 4:21PM) RE: Charging system
Tom G: The field circuit in a Ford generator has an internally grounded field (GM and MoPar don’t). Ford generator systems can be checked by grounding the field terminal either at the generator or the regulator. Grounding the field terminal either at the generator or the voltage regulator removes all regulation from the circuit and the generator will go to full charge. If it shows charge when the field is grounded, the regulator is defective. If it doesn’t show charge, the generator is defective (understand the generator could have ruined the regulator when it went bad or vice versa so both may be bad). An amp meter should show a slight charge (about 2-10 amps) in a system that is functioning properly and fully charged. If it doesn’t show a charge when grounding the field, check the wiring to make sure there isn’t wire broken or pulled loose from a wire connector… paying particular attention to the ground wire at the generator since they seem to break often at this point. When you were driving it and it began to run rough was your radio, heater, or lights on? Did turning them off cure the problem somewhat? If so, the battery itself was nearly discharged and the problem is either battery or charging system. If it didn’t make any difference when you turned them off, I think your problems are not in the charging or battery system. Check the spark at the plugs and at the high tension tower in the coil. It should jump a good 1/4 inch and be blue to yellow-blue in color. If it’s red, the distributor, coil, or condenser is bad. First thing I’d change would be the condenser since it’s easy to get to on an 8BA and condensers often quit when they get hot (I carry a spare). They won’t rpm and they’re hard to start when hot, but start good when cold. If the condenser change didn’t help, then change the coil. If the spark is good, then check the fuel for quantity and pressure. Emergency solution: I have ran a jumper wire from the field terminal to the inside of a flathead one time when coming home on leave and the voltage regulator went bad during the night. I’d ground the jumper wire to the bottom of the dash for about 10 minutes and then disconnect it for about 10-15 minutes. I drove all night doing this (sure helps keep one awake). Grounding the field terminal will cause the generator to burn up if grounded very long. Hope this helps….rumble seat

Comments

Bill M (Jan 1 2000 6:35PM) RE: Charging system
Another faster check is to wind the engine up to about 900 rpm, pull off a battery cable if engine keeps running generator is charging, regulator is probably bad, if engine dies generator is not putting out any current and is probably bad

Lars Brandow (Jan 2 2000 12:33PM) RE: Charging system
If you take a voltmeter, and messure between plus and minus on the battery posts. It should show 13,5 V or there about when the engine is running. If its lower it indicates a bad charging system. I think Rumble seat covered most of the bases anyway…

TomG (Jan 2 2000 8:35AM) rumble seat
Rumble seat Thanks for you help on my post ‘Charging system’. Once again I was off track as to what the problem was. But you were right on in your list of possible problems. I replaced the condenser, it’s even easier then the stock 8BA, because on the Mallory distributor it’s mounted on the outside of the housing. Thanks again for you time and help.