slicknapier Posted April 19, 2009 Report Posted April 19, 2009 So I'm looking at a diagram of the wiring system for my 51. As I'm looking at it I realize that my 6 volt battery is in backwards. The way my car is now the negative is going to ground and the positive is going to my starter solenoid. Everything seems to work heater, generator, wipers etc...Do I need to reverse my battery? Has any harm been done to the car by the previous owner running like this? thanks Quote
Plymouthy Adams Posted April 19, 2009 Report Posted April 19, 2009 only if you had a radio would something get damaged...the electric motors could care less as they are not pernament magnet devices...the only real thing in the ignition is what side of the points will get the sacrafice metal... Quote
grey beard Posted April 19, 2009 Report Posted April 19, 2009 Voltage regulators usually don't like having their polarity reversed, unless whomever reversed the battery also changed the generator and regulator to negative ground. You'll need to do some research on your part numbers to find out. If it was a positive ground system and someone installed the battery backwards, plan on buying a new regulator. JMHO Quote
dezeldoc Posted April 19, 2009 Report Posted April 19, 2009 That and the gauges will be backwords. Quote
Plymouthy Adams Posted April 19, 2009 Report Posted April 19, 2009 As he stated everything was working in fine it was assumed that the PO had polarized the regulator and reversed the ammeter..more that not at one time he was running a negative ground accessory that warranted the reversal.. Quote
slicknapier Posted April 19, 2009 Author Report Posted April 19, 2009 What do you guys think I should do? Put in back in like it was or how it should be? Quote
Plymouthy Adams Posted April 19, 2009 Report Posted April 19, 2009 if you are not installing a factory style positive ground radio..you may just want to let a sleeping dog lie..but then..that is again your choice...if in the future your regulator or generator go out..you could make the change at that time back to original as thus flash the new charging system as stock... Quote
slicknapier Posted April 20, 2009 Author Report Posted April 20, 2009 can I flash it now and reverse it? I would like it to be how it should be. If so, how do i flash it? Quote
TodFitch Posted April 20, 2009 Report Posted April 20, 2009 It is the generator that needs to be flashed not the regulator. Just turns out the easiest place to get to the wires for flashing the generator is at the regulator. There is not enough iron in the regulator to hold a residual magnetic field. There is enough in the generator and that residual field is what the generator uses to get itself started generating. And you need the correct polarity on that residual field in the iron core to get the correct polarity electricity out of the generator. On a stock car the coil and points work better on the correct polarity and the ammeter needs to be wired correctly. Other than that most things (field coil type DC motors, light bulbs, etc.) are, as stated earlier, insensitive to polarity. If you have a modern permanent magnet DC motor then that will be voltage polarity sensitive. So a modern heater motor or electric wiper motor retrofitted into the car might care. But the stock stuff doesn't care. Quote
slicknapier Posted April 21, 2009 Author Report Posted April 21, 2009 I think I'm just going to leave it alone. Everything is working properly, so I don't want screw something up that is already working. Quote
DigmyP18 Posted July 4, 2009 Report Posted July 4, 2009 I have pretty much the same question about reversing the battery. My 49 P-18 has the battery installed with the Negative going to ground and my headlight and dash lights and brake lights don't work. My Amp meter says that my system is charging but my voltage doesn't go up with engine RPM's. What am I missing? Any ideas. Have service manual on the way but I'm trying to drive it today. Quote
DigmyP18 Posted July 4, 2009 Report Posted July 4, 2009 Well they did work for a short while with the battery this way but now I have nothing. Is there a fuse I'm overlooking? Running lights do work though Quote
48mirage Posted July 5, 2009 Report Posted July 5, 2009 Confusing question from a lurker. Let's say the battery is in backwards and the system is discharging, which way would the ammeter read in the original configuration? Quote
Don Coatney Posted July 5, 2009 Report Posted July 5, 2009 Confusing question from a lurker. Let's say the battery is in backwards and the system is discharging, which way would the ammeter read in the original configuration? If the charging system is working correctly the needle should point slightly to the (+) side after the vehicle has been running for 10 minutes or so and the RPM's are above idle speed. If the polarity is reversed the needle will point slightly to the (-) side after the vehicle has been running for 10 minutes or so and the RPM's are above idle speed. Quote
Reg Evans Posted July 7, 2009 Report Posted July 7, 2009 One of the old trucks I dragged home years ago had a new 6 volt battery installed backwards by the p.o. It would start and run just fine but the amp gauge showed a neg charge when running. I reversed the cables and all was well. I don't think it had been this way very long though. Quote
DigmyP18 Posted July 9, 2009 Report Posted July 9, 2009 Forgetting about the backwards or not for a moment, how about this? On your personal 6 volt system (either ground ok) What is your Battery Voltage at rest and what is it while running? At idle? Maybe rev it a bit? What range of Voltage do you see? Fire away. Quote
BobT-47P15 Posted July 10, 2009 Report Posted July 10, 2009 This has really nothing to do with an answer for the question at hand......but it involves a backward battery. A guy who bought a P15 coupe from me back in the 70s installed his new batter backwards. I recall he said he had to replace something - maybe voltage regulator. Whatever it was, I thought it was poetic justice --- as he had given me this big story about being the last old car he would probably buy, etc, etc.......then he turned around and put it for sale in Hemmings. For notably more money, of course. I had given him some off my price as I fell for his story. He was an older guy. Which goes to show a.....holes come in all ages. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.