Hi,

I am trying to help a friend with his truck. I gave him my answer, but I could be incorrect.

Here is his question:

I need to know if my 6 Cyl 3100 55 Chevy truck is Pos. or Neg. ground. All the original parts are there but there is no wiring except for the battery cables. From the looks of the cables it looks like it could have been positive ground. The truck is a second generation body style. Thanks in advance for any help

negative ground

All Chevrolets are negative ground.

Thanks for the responses.

He has a wiring diagram for a '55 Truck and he tells me it shows the (+) positive post battery cable going to ground.

Thanks again.

Nope...negative ground. He might want to look at his wiring diagram again to make sure he is reading it correctly. I looked at my 1955 wiring diagram and it shows the negative battery cable going to ground as it should.

AND JUNKYARD DOG'S ARE SMART!

Junkyard Dog,

Do you have the ability to scan that portion of the wiring diagram and email it to me? I would like to have a copy when I talk to him about his truck.

Thanks

Sorry, I don't have a scanner. However, you can probably find a wiring diagram on line.

OK, thanks just the same.

I can find one for ALL MODEL passenger cars, but can't for a TRUCK application.

He did send me the wiring diagram that he has and it does show the + Positive going to Ground. BUT it is not for CHEVROLET, in my opinion of what I saw.

Thanks for all of the responses.

GMC's had positive ground, not sure how many years though

I bet that he has a wiring diagram for a GMC.




Thanks

...That could be...GMCs had a positive ground 6 volt system, when they changed to negative ground I don't know.....

I was thinking the exact same thing.

Just a dummy here, but I thought that all 12 volts systems were negative ground regardless of manufacture of vehicle and as the 55 second generation mentioned above would be 12 volt, thus negative ground???

Correct me if I am wrong on my first question please.

Jim.

1955 GMC trucks were still 6-volt and positive ground.

If the wiring diagram is not for Chevrolet then there is the answer since all Chevrolets were negative ground, not positive ground.

Thanks Ray.

Jim.

I tried to tell my friend that it was NEG ground. He now believes me because I have been sending him the replies to my original question.

Thanks for all of the replies.

I am still in-search for a 1955 2nd series Truck wiring diagram if anyone can help.

The Filling Station has truck wiring diagrams.

Contact your friend and inform him that you were mistaken and that it is POSITIVE ground and 6-volt.

Here is the original question from Chevykid's friend:



Since Chevykid's friend apparently owns a Chevrolet truck and not a GMC Chevykid gave his friend the correct answer.....negative ground.

If I misread his post, then it is a Chevrolet and not a GMC, so it would be as you suggested, a negative ground.

My bad.

There are a few 12 volt positive ground vehicles out there... The 1955 Packard comes to mind. They were 6v positive ground in 1954, 12v positive ground in 1955 only, and switched to 12v negative ground for 1956.

A funny story comes to mind. Classmate of mine had a 70 Chevelle that he had bought from some hack. He goes off and buys some $800 Stereo with big subwoofers and such. The guy he bought the car from didn't pay much attention to color codes on battery cables. The car was still Neg. Ground, but, he used a black cable on the + and Red on the - Classmate destroyed 3/4 of his new stereo cause he didn't check out the actual posts of the battery. Oops!

That is interesting. Yesterday I was going to attach a battery charger to a '51 Chevy that I recently purchased. One cable was black and the other blue. Something told me to double check before hooking up the clamps. Yup, the blue one was bolted to the engine block and the black one went to the starter. Good to always check to be sure before you mess up something, like your face from an exploding battery.

Thanks for the response sticknover.

Jim.