Two Ground Straps?

[NewSixCoupe]

Doing a bit of detailing and wire management and noticed two braided ground straps going from the negative battery cable to ground on the chassis. You can see the one strap that is part of the cable connected to the ground, and the "extra" disconnected strap in my hand. It was also running from the negative cable to the ground. Do I really need it?

Thanks.

 

[HB Chris]

Len,

Your battery should have the negative terminal towards the front with the short braided ground strap to the fender. Your terminals are reversed. You need a second braided strap from under the rear carb/manifold to the firewall. This will prevent any damage to the wiring when you start the car and the current is searching for a good ground.

 

[HB Chris]

Here are two pics.

 

[NewSixCoupe]

Chris,

The short braided ground strap does run from the negative cable to the fender. The terminals do face the rear of the car, but this is how my mechanic installed this battery about five years ago. I'll check to see if there's a strap running from the rear carb/manifold to the firewall. If there is, do I need this second strap running from the negative cable to the fender? This seems redundant.

Thanks.

 

[NewSixCoupe]

Wait a minute, one of us (probably me) misinterpreted our photos. My negative terminal DOES face the front of the car like the photo you posted...

 

[NewSixCoupe]

I'll post a better photo...

 

[NewSixCoupe]

OK, the ground strap to the firewall is there just like in your photo. Here's a better shot of my battery.

 

[NewSixCoupe]

Don't know why these photos rotate like this!

 

[bmw art car]

my wire looks different... i have a wide strap maybe 2"
and a smaller strap maybe 1" one is maybe 6" inch long the other
12", guesstimated. so it's supposed to reach from the battery all the way to the firewall? or did i misread that?

 

[Bwana]

The negative on my car is towards the front. I bought a ground harness from a late '70's 5 series (can't remember which one) from the dealer. It has a mondo cable that goes to the oil filter bolt to ground the engine/starter and the braided one that goes to the fender.

 

[HB Chris]

My mistake Len, the pic was pretty small. If the big brown ground runs to the motor mount or nearby that is good. I think the motor also needs a ground, this was advise from Mesa. The draw from the starter can do weird things and damage other components without a good ground, maybe the alternator wires but I can't remember for sure. I would leave the braided ground as well, it won't hurt.

Q: does the `74 have those extra ground ground wires bundled and also tied to the fender bolt? My `73 does not but `74 wiring is different with fuses and relays.

 

[61porsche]

Wag

The wiring diagrams indicate connections for options. ( Headlight washers, fogs etc.) Certain Markets, Italy for example, show being wired differently.

Perhaps its from an option, or something added and removed by a previous owner/ dealer.

For CS, there were two grounds. For CSI, there were three. The third being from the valve cover stud near #1 cylinder to near the ballast resistor. All are shown in the manual- engine removal/ installation photos/ text.

Len- FYI, I have a short brown ground at the battery negative rather than the braided original too. Something on my long list to get to. If the wire isn't hooked up, hasn't been hooked up, never will be hooked up... it's your call.

When all the FI conversions started, it was discovered that sometimes adding the third ground solved many gremlins... it's a good idea.. in addition to going over 40 year old connections.

 

[NewSixCoupe]

Chris, yes I have the additional brown bundled wires going to the fender along with the integrated braided strap from the negative battery cable.

I never had any electrical problems with the extra braided strap attached from the negative battery cable to the fender, so I think I'll just reinstall it and leaves things as they were. Just seemed strange to me to have that redundancy.

You learn something new on this site every day.

Thanks everyone!