Factory Battery Ground Location?

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Topic author
spjohnson1031
Posts: 20
Joined: Mon Jun 21, 2021 7:59 pm

Factory Battery Ground Location?

Post by spjohnson1031 »

Hey all,

I recently acquired a 1970 Wagoneer with MANY electrical gremlins. The previous owner has the wagon grounded from the battery to the bracket supporting the heater hoses (into the intake) and then a secondary ground running to the side of the heater box. There are also remnants of what USED to be a ground still partially connected to the motor mount. However, what's left connected to the motor mount is way too short to have ever reached the factory battery location. Where should I be attaching my battery ground?

Thanks in advance!

Scott
~Scott

1970 Jeep Wagoneer
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tgreese
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Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: Factory Battery Ground Location?

Post by tgreese »

Usually the battery ground goes to somewhere on the engine, and then there is a jumper from the engine to the frame. There can also be a wire (like 10 or 12 gauge) going directly to the body sheet metal.

The jumper is sometimes flat wire braid, or regular stranded wire could be used. I believe the flat braid is used because of the vibration and movement between the frame and the engine. The battery ground cable is long and made of finely stranded cable, and can withstand the movement.

Replacement braids are available https://www.custombatterycables.com/bra ... nd-cables/ likely lots of other places too.

Short cables with eyes on each end would work - https://www.rockauto.com/en/tools/elect ... cable,2500

I think you'll need to see another Jeep of the same year and equipment to put it back to exactly the original condition. Really, all it need to be is sufficient grounded or better. Body - frame - engine.
Tim Reese
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rocklaurence
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Re: Factory Battery Ground Location?

Post by rocklaurence »

Im not certain of the Pre-'80s FSJs but the post ones had the grd going to the AC compressor bracket. The small one on the motor mount is to jump over the rubber isolator back to the frame--these fail over time or are left off after replacing the motor mounts. I run s heavy cable to the AC bracket and then another to the body fender and from the fender grd to the frame bellow the battery. I once burnt off the 10awg from the battery to the body because the motor mount jumper wire rotted off.

Triumph215
Posts: 215
Joined: Thu Jan 07, 2021 8:42 pm
Location: Monterey, Ca

Re: Factory Battery Ground Location?

Post by Triumph215 »

I have a '77. Mine goes from the battery to a bolt directly under the head on the passenger side behind the alternator and from there the the motor mount on the passenger side. I've researched this and this seems to be the 'correct' set up but the guys are right that you just need good grounds to engine, frame and body. Mine all seemed fine but I was still having a voltage loss problem so I replaced them and that fixed 90% of the problems.
1964 Triumph TR4 with 1964 Olds 215 heart transplant
1977 Wagoneer
2009 BMW GS1200

Topic author
spjohnson1031
Posts: 20
Joined: Mon Jun 21, 2021 7:59 pm

Re: Factory Battery Ground Location?

Post by spjohnson1031 »

Thanks, all!

I regrounded my battery to the motor mount and ran a strap from the motor to the firewall. Thanks for the help.
~Scott

1970 Jeep Wagoneer
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