Battery hooked up backwards and it ran????

[Guest Jeff_Miller]

I bought a 1936 Special that made it home July 2 and it is definetly full of surprises. The latest was that I was that when I began to investigate the week battery I found that it was connected backwards. Positive was going to the ground, and the negative headed off to the starter. Huh???? This thing started and ran in that configuration - how come?

Since the cables are questionable I plan to replace them but I am not sure what gauge to look for. The common 4 gauge is definetly too small but is 2 gauge good enough? If not, any suggestions on where to find 0 or 00 gauge? I have seen some on line but I sure would like to get this thing running again and hope to find something local.

Jeff

[Guest imported_JPIndusi]

Go to a local truck parts store if you cannot get heavy cables at NAPA or other auto parts store.

2 Gauge is marginal, 1 gauge will work if everything else is OK, 0 will be fine if there is no long run from the battery to the frame or starter.

Good luck.

Joe, BCA 33493

[Guest]

Of course it would run. All the engine needs is spark, compression and fuel. It dosen't care which way the electrons run. As soon as it was running it should have been obvious by looking at the ammeter that it was connected backwards. The ignition system is usually designed to operate better one way than the other but it would certainly supply spark either way.

[Guest Jeff_Miller]

I can understand that once the vehicle started it would keep running but shouldn't the starter have been turning the wrong way? I would imagine that the generator would have been doing bad things to the battery as well. Luckily it wasn't running for too long.

The local auto parts stores are pretty worthless but the truck supply might be just the ticket.

Thanks for the help.

Jeff

[Guest 1936buick]

Dave

You need to read a manual!

Most 6 volt cars are NEGATIVE not positive ground.While my relatively rare 1928 Packard is positive ground my 1930,35 and 36 Buicks are all negative ground.My 1936 Buick shop manual states "make certain the negative terminal is grounded."

Stan

[37_Roadmaster_C]

Hi Jeff,

I won't be much help but I will follow this for my own information. I have a 37 Roadmaster Convertible and it is like your 36 and is negative ground. My experience with the old Buicks is that the generator probably survived the backward battery, but may have been reverse polarized, if so it will need to be re-polarized properly. I don't remember the procedure but someone here on the forum will know I'm sure. To check this just correct the battery polarity, start her up and watch the amp meter on the dash. If it shows a charge then you are OK. I, like you, don't understand how the car could start (starter would run backward). If someone could explain this I would be grateful.

[ziegl1938]

Most starter motors will spin the correct direction regardless of polarity. I've converted a couple of cars from 6 volt positive ground to 12 volt negative ground without having any problems with the starter motor regarding either voltage or polarity. But any time the polarity is changed the charging system must be polarized to prevent damage to the regulator and/or generator. Some heater motors will run in opposite directions depending upon polarity, but not all of them. It depends on internal design. Electrical instruments will need the wiring connected properly or they will read backwards.