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Discussion Topic:
Charging System Question
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TomO |
06-25-2021 @ 8:06 AM
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Senior
Posts: 7256
Joined: Oct 2009
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You should check the generator grounding at the intake manifold. Clean the mounting surface of the generator and the intake manifold. If you don't have a grounding strap from the firewall to the engine, install one. The correct spot on a 39 Deluxe would be to a head stud, but in 1940 Ford changed to the intake manifold bolt and that is where I prefer it to be.
Tom
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39Fordfan |
06-24-2021 @ 10:54 AM
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Member
Posts: 202
Joined: Oct 2009
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TomO, Great stuff as usual. Thank-you. I'm going to find and pick up a meter with a needle. I've wondered why my digital meter never showed much on this car. Thanks for that tip. I used your trick to better ground the new regulator. It didn't help with the overcharge situation of the new regulator, but it did help to boost the charge for the old weaker regulator. Go figure, right? I took the new regulator out and I'm now driving with the old regulator since it does still charge and will charge higher at a higher rate of speed. The weaker charging seemed safer than to drive it and leave it overcharging. I'll leave it with this set up until I can get the car into the rebuild shop in a couple of weeks. Thanks!
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39Fordfan |
06-24-2021 @ 10:44 AM
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Member
Posts: 202
Joined: Oct 2009
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51woodie, I will be taking the car back to the rebuild shop with both the new overcharging regulator and the old underperforming regulator. Unfortunately they won't be able to take me until after the 4th of July. So I just took replaced the new regulator with the old one as it was definitely over charging. I just wasn't sure exactly which one to use until I could get it back to them. I decided the old regulator was strong enough so that's what's in the car until I can get it into the shop.
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39Fordfan |
06-24-2021 @ 10:38 AM
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Member
Posts: 202
Joined: Oct 2009
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1931 Flamingo, Thank-you for your reply. I did take both the regulator and the generator to the shop initially. They recommended a new regulator, which I got but it was overcharging. The part I neglected to mention is that they will not be able to look at my car until after the 4th of July. So I took the new regulator out because it was overcharging and put the old one back in until I can take them both in after the holiday to look it over. Thanks for your help!
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TomO |
06-22-2021 @ 8:53 AM
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Senior
Posts: 7256
Joined: Oct 2009
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I would check to make sure that your new voltage regulator is properly grounded. Connect your voltmeter COM lead to the base of the regulator and the + lead to the POS post of the battery. Start the car and let the engine idle, the voltmeter reading should be 0.1V or less. Increase engine speed to about 1,500 RPM and read the meter. It should read 0.1V or less. If the reading is higher, clean a spot under one of the mounting tabs and put a toothed washer between the mount and the firewall. If you do not have a meter, you can just try the washer. Next, I would connect the voltmeter COM lead to the BAT terminal of the voltage regulator. Start the engine and read the meter. At idle it should read about 6.2-6.4V. Increase the engine speed slowly to 1,500 rpm. The meter reading should increase to 7.2V-7.6V and stay there as the speed is increased. I would use a meter with a needle, not a digital meter for these tests. The digital meter is too sensitive to transient spikes and will b e hard to read.
Tom
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51woodie |
06-22-2021 @ 8:09 AM
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Senior
Posts: 516
Joined: Jan 2017
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When I took the generator from my '46 Coupe in for rebuild, the shop wanted my regulator as well, so they could be paired on their test setup. I was told, "No regulator, no guarantee". Installed, polarized, and operates perfect.
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1931 Flamingo |
06-22-2021 @ 6:20 AM
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Member
Posts: 388
Joined: Nov 2019
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When I had problems I took BOTH the generator and regulator to the repair shop. I would suggest you do the same (either take the parts or the car). The regulator should be able to be adjusted on the car if the shop is any good. JMO Paul in CT
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39Fordfan |
06-21-2021 @ 11:29 PM
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Member
Posts: 202
Joined: Oct 2009
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On my '39 Deluxe the engine bay and some of my electrical components got soaked by coolant awhile ago. (A different story.) I noticed the voltmeter gauge started showing that the system was on the low side of the N bar and I was getting other symptoms of low re-charging too. Then it would only charge to the bottom line well below the N Bar so that I seemed to be just running on battery. My battery is two years old and accepts and holds a charge just fine. I took the generator and the voltage regulator into a rebuild shop. They took the generator apart, cleaned it up, put in a new bearing and brushes in it and said it tested fine, but they were concerned about the voltage regulator and suggested a replacement eventually. I put them both back into the car and I saw a good improvement in the reading, back up to the the bottom of the N Bar, but still making me wonder about taking the car too far from home. I bought a new voltage regulator and installed it today. Now the voltmeter sails ABOVE the N Bar, even at idle. Now I am concerned about overcharging the system especially at highway speed. Do you share this concern? Are there tests I can run to determine if I'm over charging the battery now? Should I take the generator and new regulator back to the shop and have them recalibrate them together? Thanks!
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