| |
Click on image for the lowdown. 
====
| | |
0 members (),
35
guests, and
3
robots. | | Key: Admin,
Global Mod,
Mod | | | Forums66 Topics128,014 Posts1,055,327 Members48,419 | | Most Online14,466
Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down
with Ads!  Again, thanks!
| | | | Joined: Dec 2006 Posts: 66 'Bolter | | 'Bolter Joined: Dec 2006 Posts: 66 | Can anyone tell me how to convert an old 58 Mack from positive ground to negative ground? Thank you, Scott | | | | | Joined: Feb 2004 Posts: 29,746 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,746 | What voltage? Are you running a generator or an alternator? The starter doesn't care what polarity it gets but a DC generator needs to be re-polarized to negative ground. it will probably be necessary to obtain a negative ground voltage regulator, since there are some internal wiring differences. The simplest approach will be to retrofit to a negative ground alternator if possible.
Does the truck have a series-parallel switch for starting on 24 volts? If so, that switch will probably have to be replaced with one for negative ground polarity.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | Scott,
If you are keeping the voltage the same, what is your reason for reversing the polarity? | | | | | Joined: Dec 2006 Posts: 66 'Bolter | | 'Bolter Joined: Dec 2006 Posts: 66 | I have to convert it because all of my trailers are wired for neg. ground. Also, electric brake box will not work with pos. ground. | | |
|
|
| |
