Correct/recommended ground wires in engine bay?
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Joined: Jun 2007
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Correct/recommended ground wires in engine bay?
I have one main ground wires in my engine bay - that goes from the block to the negative terminal on the battery - there are smaller ones that ground the lights, ww pump, etc, but I am primarily talking about the main ground wires. Should there be a couple more? Block to chassis? Chassis to firewall? Block to firewall?
I recently installed a new wiring harness and believe I have some grounding issues. My main concern right now is the alternator is not charging. Had it tested twice and it tests good. Multimeter shows 12.5V on the battery when engine is off and when running.
I recently installed a new wiring harness and believe I have some grounding issues. My main concern right now is the alternator is not charging. Had it tested twice and it tests good. Multimeter shows 12.5V on the battery when engine is off and when running.
Senior User
Joined: Jul 2011
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defently a great question, my 390 has a large bolt going into side of block just behid alternator, I think it is 11/16 or 3/4, battery cables are 1/2 inch, I trying to drill to enlarge I think it will break the cable terminal end.
is there a down sized lug that might bolt into the block and allow a down size to bolt bable end to?
is there a down sized lug that might bolt into the block and allow a down size to bolt bable end to?
Posting Guru
Joined: Dec 2009
Posts: 2,134
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From: Mississippi
defently a great question, my 390 has a large bolt going into side of block just behid alternator, I think it is 11/16 or 3/4, battery cables are 1/2 inch, I trying to drill to enlarge I think it will break the cable terminal end.
is there a down sized lug that might bolt into the block and allow a down size to bolt bable end to?
is there a down sized lug that might bolt into the block and allow a down size to bolt bable end to?
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Joined: Jul 2011
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Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
The factory was kind of weak when it came to grounds. Besides the neg. battery cable to block, there was a block to firewall, and an alternator to regulator/rad. support ground. There was also a hood to firewall ground but that was to increase the ground plane for the radio antenna.
Like mark a said, you can never have too many grounds.
Besides the three above, I've added a starter to frame and a rad. support to frame on my project. And when I get the cab and bed back on I'm going to add ground to frame straps on them too.
Like mark a said, you can never have too many grounds.
Besides the three above, I've added a starter to frame and a rad. support to frame on my project. And when I get the cab and bed back on I'm going to add ground to frame straps on them too.
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Lead Driver
Joined: Jul 2017
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From: San Jose, CA
If you’re not doing a concourse restoration, it doesn’t matter that you place the ground straps precisely where Ford did it. Just ground the cab to the body anywhere that is convenient (and won’t cause a rust problem) and go to town.
Logistics Pro
Joined: Mar 2002
Posts: 3,881
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From: Wake Forest, NC
I think it's a weenie one that's clips from the cab mount bracket to a piece of sheet metal. A dedicated one at the block to the frame would be an improvement.
Hotshot
Joined: Feb 2004
Posts: 10,726
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From: The Shenandoah Valley
I'd do
- each door to cab at front of door
- hood to cab cowl / firewall
- each splash panel to the frame
- cab to floor, likely twice
- bed to frame.
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