too many ground wires?

H

hueyhoolihan

Well-known member
thoughts on running only one ground wire...from positive post of battery to one of the mounting bolts on the starter.

to test...

if successful, i should see the the temperature gauge on the dash working, meaning the block on the motor is grounded, and if the lights work, it means i'm getting a good ground to the body/frame. of course i could just run a few continuity tests, i guess.

and if either the lights or the temp gauge don't work, i'll be needing more ground wires.
 
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What is your purpose for eliminating grounds? It can come back to haunt you. Your engine/trans sits on somewhat insulating mounts. At least run a ground wire/strap from the engine to the body.
 
If original ground paths are clean and tight, resistance will be minimal. Even rubber cushion mountings generally have bolt to frame contact. If they originally had bonding straps then those should be maintained.
 
Usually, cars have the ground battery cable going from the battery to a starter mounting bolt and then a separate good size wire as the body ground, going from the engine to the firewall.

One of my first car's electrical lessons when I was 16 was, I mounted the battery in the trunk of a Mustang, like a '65 Shelby Mustang had. I ran heavy welding from the positive battery post to the starter solenoid, but then I mounted ground cable from the battery to the floor of the trunk. I went to start it; it cranked but smoke was coming from the choke cable. It never occurred to me that the starter current was flowing though my choke cable that's weird, dumbass me grabbed the choke cable and burned the crap out of my hand, it left a spiral burn pattern on my hand, I might as weel have placed my hand on a barbecue. Being young, that's when I learned that the engine has to have a large ground for the starter. I didn't think about the engine having rubber mounts, the trans had a rubber mount, the rearend set on springs with rubber mounts, everything in the drivetrain was isolated from the cars body by rubber. The only ground the electricity could find when I hit starter was the mechanical choke cable, not good, not good at all. So, I gave it a large ground from the engine to the body, and it was fine after that.
 
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Flathead Fever said:
Usually, cars have the ground battery cable going from the battery to a starter mounting bolt and then a separate good size wire as the body ground, going from the engine to the firewall.

One of my first car's electrical lessons when I was 16 was, I mounted the battery in the trunk of a Mustang, like a '65 Shelby Mustang had. I ran heavy welding from the positive battery post to the starter solenoid, but then I mounted ground cable from the battery to the floor of the trunk. I went to start it; it cranked but smoke was coming from the choke cable. It never occurred to me that the starter current was flowing though my choke cable that's weird, dumbass me grabbed the choke cable and burned the crap out of my hand, it left a spiral burn pattern on my hand, I might as weel have placed my hand on a barbecue. Being young, that's when I learned that the engine has to have a large ground for the starter. I didn't think about the engine having rubber mounts, the trans had a rubber mount, the rearend set on springs with rubber mounts, everything in the drivetrain was isolated from the cars body by rubber. The only ground the electricity could find when I hit starter was the mechanical choke cable, not good, not good at all. So, I gave it a large ground from the engine to the body, and it was fine after that.
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this is pretty much what i was thinking about, but plan on testing whether or not i really need the motor to firewall ground. like if the lights or maybe any of the gauges with sensors in the block, or the fuel level sensor that's grounded to the trunk floor don't work properly, i'll add one or two more.
 
Grounds are the forgotten devil and need to be appeased 1 they cant be to big 2 cant have to many bad earths cause so much drama and they must be able to handle the collective total of the system draw at any time [Most electrical failures can be attributed to bad or low capacity earths ] So in simple terms the bigger the better
 
If one of you grounds are removed and one is so so , you could damage your choke cable or worse a temp or oil gauge , speedo cable etc . Brings me back to a 20 yr old me , working as a mechanic and a gm product is pulled in on a wrecker . It would not shift out of gear . Auto trans , floor shift, new sears battery . Someone didn’t install the proper ground cable or had it loose , can’t remember. But it started by grounding through the auto trans shifter cable . Cable was welded and burnt , melted the internal nylon sheath.
 
Uncle Raeman taught me early when a farm truck or other old Ford came in with any problems, bring a ground to the problem. Lose rivets on frame joints are a nightmare. I use a heavy wire ground between block to frame and separately to car body. Clem
 
Had to weigh in here too.

I put my 3rd engine in my 1996 Tahoe back in 2018. Weird problem I began having was after the engine was hot and I shut it off I then could not get it to fire. It would crank but not run. I'd wait about 20 minutes for the engine to cool down and then I was able to crank it up again.

Then it happened outside a NAPA Parts store and one of the staff came out to lend a hand. He phoned his retired GM Electrical Engineer dad and put him on speaker. After listening to all the facts he said... 'Check the ground to frame connections... probably loose'. Well when we looked, not only were they lose, the connection to the block was not even fastened. Ground wire was dangling loose. The old engineer went on to explain that as the wires heated then so did the electrical resistance in the wire making the need for a good ground even more critical. He even suggested replacing any braided grounding straps with large gauge shielded wire. Did all that and now seven years later still no issues.

I have to say too that it does not fire up as quickly as my '35 Ford on 6-volts still... but it always does fire up. :)
 
ScubaChief60 said:
Had to weigh in here too.

I put my 3rd engine in my 1996 Tahoe back in 2018. Weird problem I began having was after the engine was hot and I shut it off I then could not get it to fire. It would crank but not run. I'd wait about 20 minutes for the engine to cool down and then I was able to crank it up again.

Then it happened outside a NAPA Parts store and one of the staff came out to lend a hand. He phoned his retired GM Electrical Engineer dad and put him on speaker. After listening to all the facts he said... 'Check the ground to frame connections... probably loose'. Well when we looked, not only were they lose, the connection to the block was not even fastened. Ground wire was dangling loose. The old engineer went on to explain that as the wires heated then so did the electrical resistance in the wire making the need for a good ground even more critical. He even suggested replacing any braided grounding straps with large gauge shielded wire. Did all that and now seven years later still no issues.

I have to say too that it does not fire up as quickly as my '35 Ford on 6-volts still... but it always does fire up. :)
Click to expand...

00 grounding strap ordered and on the way that will replace braided strap currently running from a nut on the rear of the engine block to the firewall. but will now run from the block to the frame. am currently waiting on another 00 wire that will be long enough to run from the solenoid to starter. the wire that is there now is much smaller in diameter.
 
Just my $0.02
Absolutely a frame ground BUTT a good body ground is in order also. With a fame only ground you depending on continuity between the frame and the body. The body is where most lighting and accessory grounding take place.
 
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