The Ford Barn

Will N · 05-02-2024, 10:22 AM

Was driving my Fordor the other day. It started and ran fine the whole trip, but a mile or so from home the ammeter suddenly showed a 15 amp discharge. It normally shows about a 4-6 amp charge when underway. I run a stock generator with a diode cutout. I have a fuse for the whole electric system mounted on the starter. I have signal stat turn signals installed, and no other accessories. When the discharge happened, there was no change in the way the engine ran, so I suspected maybe the brake light switch stuck. When I got home I checked the lights, and none were on. No turn signals were flashing. The fuse did not blow, so I don't think there's a dead-short anywhere. If I revved the engine the discharge would change from -15 amps to about -4 amps, so the generator is putting out a charge. It was a warm day- about 85F. I turned off the ignition and the ammeter went right to 0. I started the car the next day after it had cooled down and the ammeter showed a 4-6 amp charge at a fast idle. I didn't let it run long enough to get hot. Any suggestions on what my have caused the discharge?

05-02-2024, 10:22 AM	#1
Will N Senior Member Join Date: Jul 2010 Location: Pennsylvania Posts: 1,115	Ammeter showed a discharge Was driving my Fordor the other day. It started and ran fine the whole trip, but a mile or so from home the ammeter suddenly showed a 15 amp discharge. It normally shows about a 4-6 amp charge when underway. I run a stock generator with a diode cutout. I have a fuse for the whole electric system mounted on the starter. I have signal stat turn signals installed, and no other accessories. When the discharge happened, there was no change in the way the engine ran, so I suspected maybe the brake light switch stuck. When I got home I checked the lights, and none were on. No turn signals were flashing. The fuse did not blow, so I don't think there's a dead-short anywhere. If I revved the engine the discharge would change from -15 amps to about -4 amps, so the generator is putting out a charge. It was a warm day- about 85F. I turned off the ignition and the ammeter went right to 0. I started the car the next day after it had cooled down and the ammeter showed a 4-6 amp charge at a fast idle. I didn't let it run long enough to get hot. Any suggestions on what my have caused the discharge?