# 12 Volt positive ground **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [September 22, 2012, 11:28pm UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647 "2012-09-22T23:28:54Z")\ **Posts on this page:** 13\ **Page:** 2
**Author:** ![RemcoW](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/remcow/32/2471_2.png) [@RemcoW](https://community.cartalk.com/u/RemcoW)\ **Post date:** [September 23, 2012, 5:28pm UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/21 "2012-09-23T17:28:18Z")
@MG1952: “dramatic warning light” - that’s funny. ---
**Author:** ![euryale1](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@euryale1](https://community.cartalk.com/u/euryale1)\ **Post date:** [September 23, 2012, 6:43pm UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/22 "2012-09-23T18:43:45Z")
Hey Stevef, Sorry to hurt your tender feelings. I am wrong all the time but tend to get over it. As to electronics I am often correct. I never say I know it all. ---
**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\ **Post date:** [September 24, 2012, 12:54am UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/23 "2012-09-24T00:54:10Z")
To satisfy my curiosity I just connected this fuel pump [http://www.autozone.com/autozone/accessories/Airtex-Products-2-5-to-4-PSI-25-to-30-GPH-electric-fuel-pump-for-vintage-classic-carbureted-applications/](http://www.autozone.com/autozone/accessories/Airtex-Products-2-5-to-4-PSI-25-to-30-GPH-electric-fuel-pump-for-vintage-classic-carbureted-applications/)_/N-25jp?itemIdentifier=963381\_0\_0_ correctly and incorrectly and it failed to operate unless the polarity was correct. Honestly, I thought it would work either way. ---
**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\ **Post date:** [September 24, 2012, 1:05am UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/24 "2012-09-24T01:05:03Z")
I need clarification. Why not install the pos of the battery to the pos cable for the car, which coincidentally should go to ground? Wont the Terminals not allow you to incorrectly install the battery. The biggest danger I see would be in jumping the car if metal bumpers are touching. Confused! edit Sorry I thought the guy meant reversing the polarity of the battery. ---
**Author:** ![MTraveler](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@MTraveler](https://community.cartalk.com/u/MTraveler)\ **Post date:** [September 24, 2012, 7:35pm UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/25 "2012-09-24T19:35:44Z")
Speculation without specific information about the pump is a losing proposition. Google is a wonderful tool for answering these types of questions. This online vendor has specific instructions for installing its product, all of which are listed as -ground, in +ground applications: [https://www.pegasusautoracing.com/document.asp?DocID=TECH00072](https://www.pegasusautoracing.com/document.asp?DocID=TECH00072) The Airtex E8902 mentioned by RN will work in a +ground application, but is 6v. > **[6 VOLT FUEL PUMP OR PRIMER PUMP 2.5-4psi POSITIVE NEGATIVE GROUND PRIMER FUEL...](https://ezautoparts.ecrater.com/p/14510889/6-volt-fuel-pump-or-primer-25-4psi)** > > 6 VOLT FUEL PUMP 2.5psi-4psi 25gph-30gph Inlet Outlet 5/16 Free Flow POSITIVE or NEGATIVE GROUND ALSO CAN BE USED WITH EXISTING PUMP IN PLACE AS A PRI The Airtex E84259 12v works in a +ground application. It looks a little over sized to me. [http://www.oreillyauto.com/site/c/detail/AIX0/E84259/N2261.oap?ck=Search\_N2261\_-1\_-1&pt=N2261&ppt=C1980](http://www.oreillyauto.com/site/c/detail/AIX0/E84259/N2261.oap?ck=Search_N2261_-1_-1&pt=N2261&ppt=C1980) The OP should research his particular pump. Mr. Knox, Kudos for testing your theory, more so for reporting the results. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [September 24, 2012, 7:47pm UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/26 "2012-09-24T19:47:52Z")
@MTraveler - it also sounds like the output pressure is an issue for this car, not just positive vs. negative ground, is that addressed in those listings? ---
**Author:** ![MTraveler](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@MTraveler](https://community.cartalk.com/u/MTraveler)\ **Post date:** [September 24, 2012, 10:11pm UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/27 "2012-09-24T22:11:19Z")
Pegasus has listings for small carbureted engines. [https://www.pegasusautoracing.com/group.asp?GroupID=FUELPUMPLOW](https://www.pegasusautoracing.com/group.asp?GroupID=FUELPUMPLOW) Airtex also has recommendations, but isn’t as thorough about indicating what will work with a +ground. [http://www.airtexproducts.com/](http://www.airtexproducts.com/) The Airtex E8902 seems to have ideal specs., but is 6V. ---
**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\ **Post date:** [September 25, 2012, 12:35am UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/28 "2012-09-25T00:35:03Z")
It works fine at 12 volts. I have used it to pump down fuel tanks for many years, most recently I emptied an 18 gallon tank on a boat. When rebuilding carburetors I can bench test the float setting. ---
**Author:** ![researcher](https://avatars.discourse-cdn.com/v4/letter/r/edb3f5/32.png) [@researcher](https://community.cartalk.com/u/researcher)\ **Post date:** [September 27, 2012, 2:19am UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/29 "2012-09-27T02:19:17Z")
Looks like “MoMini” has left the room and left us in suspense. ---
**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\ **Post date:** [September 27, 2012, 2:39am UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/30 "2012-09-27T02:39:04Z")
Do not attempt to isolate the pump body from ground. The body must be properly grouded to prevent the possibility of a static discharge. And I strongly recommend against reversing polarity. Just as the electrode in your hot water tank at home functions based on flow in a particular direction, so does your pump assembly. And you also might inadvertantly create a “hot” circuit through the gasoline that you’d be better off without. I strongly suspect that the pump is designed to not compromise the grounding of the tank…don’t play games with this one. Return this and get the proper pump. The kid at the counter made some assumptions based upon some basic DC motor theory. But I don;t recommend that you make ANY assumptions when dealing aith a tank of gas. ---
**Author:** ![MoMini](https://avatars.discourse-cdn.com/v4/letter/m/85f322/32.png) [@MoMini](https://community.cartalk.com/u/MoMini)\ **Post date:** [September 27, 2012, 9:09am UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/31 "2012-09-27T09:09:46Z")
Thank you all. The manufacturer recommended I return the pump. I remembered an article about changing polarity for positive ground british cars to negative ground and looked it up. It is really quite simple (I have not done it yet) and will allow any negative ground accessory to be used. It should take about 5 minutes. I think that will be my solution rather than buy a $150 pump. ---
**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\ **Post date:** [September 27, 2012, 9:22am UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/32 "2012-09-27T09:22:27Z")
Changing the system over to negative ground is not that difficult except for the radio, if so equipped… ---
**Author:** ![MG-McAnick](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mg-mcanick/32/188_2.png) [@MG-McAnick](https://community.cartalk.com/u/MG-McAnick)\ **Post date:** [September 28, 2012, 8:18am UTC](https://community.cartalk.com/t/12-volt-positive-ground/74647/33 "2012-09-28T08:18:39Z")
Perhaps the Autozone guy meant that you could switch the polarity on your car. Naaahh, probably not. He’s probably not aware that you can do such a thing. Take a look at this online article. [http://www.ndmmcc.org/negconv.htm](http://www.ndmmcc.org/negconv.htm) Follow the directions, and Bob’s your uncle. Sorry I got here late. [Previous page](https://community.cartalk.com/t/12-volt-positive-ground/74647.md?page=1)