TheSamba.com :: View topic - Negative or Positive Ground Electrical System

Tue Jan 15, 2013 9:51 pm

Does a VW have a negative or positive ground electrical system? I'm guessing Negative? Thanks for the help

Tue Jan 15, 2013 10:00 pm

You guessed it, it's Negative

Tue Jan 15, 2013 10:31 pm

I'm positive it's negative.

Wed Jan 16, 2013 6:30 am

^^ =D>

Max

Wed Jan 16, 2013 7:33 am

That's a negative on the positive ground question.

Wed Jan 16, 2013 8:36 am

Just wanted to be sure. Thanks to all that responded.

Wed Jan 16, 2013 9:35 am

Since the original question has been answered conclusively, can I throw out a follow up question? I thought British cars were "positive" ground but my friend's TR6 is negative. Was there a point at which British cars converted? Or are some of them still "positive earth"?

Wed Jan 16, 2013 11:28 am

Well, never mind, I looked it up. British cars were "positive earth" up to the 1960's. But not now.

Wed Jan 16, 2013 11:52 am

My 1946 Farmall H was 6 V positive ground, but I changed it to 12 V negative ground and installed the Bosch 12V regulator.

Wed Jan 16, 2013 1:17 pm

Well you know it is not a British car like an MG which is a + ground.
German VW's are - negative ground.

Wed Jan 16, 2013 1:30 pm

Wed Jan 16, 2013 2:24 pm

Many vehicles over the years have been positive ground.

Ford - from 1928(Model A's) up into the '50's in the 6 volt systems. Model T Fords(1927 and earlier) that were starter equipped were negative ground. I have always wondered why the change to positive ground in 1928.

Chrysler - up into the '50's(6 volt).

British cars and many other makes no longer produced like Studebaker, Hudson, Packard, DeSoto, Nash, ...

Wed Jan 16, 2013 2:38 pm

79SuperVert wrote: Since the original question has been answered conclusively, can I throw out a follow up question? I thought British cars were "positive" ground but my friend's TR6 is negative. Was there a point at which British cars converted? Or are some of them still "positive earth"?

I think everyone started standardizing on negative ground around the time diode rectifier alternators were introduced. You can't easily switch between pos/neg ground like you can with a generator. Not having to worry about potentially mixing two systems up during jump starts/maintenance is a bonus.

Plus there's the argument that the positive battery terminal creates more corrosion in bare metal connected to it, like the body/chassis in a positive ground car, than when connected to the negative terminal. In a negative ground car, the wiring should corrode faster but then the insulation has gotten better since the old woven cotton.

I think there's also some benefit in avoiding radio static.

Thu Jan 17, 2013 8:45 am

IMO it was about the hole vs. electron theory of current flow. It was 'believed' current goes from - towards + (electron theory). The + was the logical choice for all of the 'used' electricity to go.

Fri Jan 18, 2013 8:08 am

They used to ground positive the vehicles, in order to avoid corrosion. Only for low voltage applications (5-6 volts).

12 volts and more should be grounded common negative.

Fri Jan 18, 2013 4:49 pm

The genius who rebuilt the engine last in my 67 Used a red cable for the chassis ground and a black cable for the cable to the starter. Always have to remind myself to hook it up reverse of the colors. Wired it up wrong once, Starter wasn't happy.

Fri Jan 18, 2013 5:53 pm

A67what wrote: The genius who rebuilt the engine last in my 67 Used a red cable for the chassis ground and a black cable for the cable to the starter. Always have to remind myself to hook it up reverse of the colors. Wired it up wrong once, Starter wasn't happy.

For God sake man, how hard can it be to reverse the PO's Screw up and make it right. after all your just perpetuating the PO's screw up. :D

Fri Jan 18, 2013 9:44 pm

lovethatconvertible wrote: A67what wrote: The genius who rebuilt the engine last in my 67 Used a red cable for the chassis ground and a black cable for the cable to the starter. Always have to remind myself to hook it up reverse of the colors. Wired it up wrong once, Starter wasn't happy.

For God sake man, how hard can it be to reverse the PO's Screw up and make it right. after all your just perpetuating the PO's screw up. :D
The starter wire is usually longer than the ground wire. He could wrap the red wire in black tape and black wire in red tape. Cheaper than replacing wires with the price of copper.