The Stovebolt Site Forums The Shop Area The Electrical Bay Grounding Strap (engine to frame) - none on my 51 GMC

Hey Guys,

I have an interesting one for you. The other day, I was looking for an electrical part for my `51 GMC 281-22 series. On the website's page, they had pictures and descriptions of their parts. As I was scrolling down, I came across an engine to frame grounding strap--those flat, braided, metallic straps. Then it hit me: I don't have any on the truck. Previous owner(s) must have let them fall off or took them off.

So, just how serious is that? And, if I bought some, how many would I need? Where exactly do they mount?

Thanks!
Mike

On my 250-22, the strap mounts to the passenger frame from the bolt that holds the starter linkage to the bell housing.

Most all modern cars have them. When the engine mounts all started going to non conductive bushing and other assorted non conductive hookups the "engine metal" lost its circuit to negative and ground.
Therefore ye ole ground strap was needed. in theory they can be anywhere from engine clean metal to frame, body clean metal.
Most put them behind the engine to cab body to get them out of the way. Braided strap (used for flex and less likely to break when moved) or even copper wire will work(which i use because it more more like original wiring);

Do you need them ? Well only if you have mounts and other items that are allowing the engine to not have a very good circuit. But it sure does not hurt to have them.
If your going for a true restoration and where they go then consult the manuals or ask some of the true restoration guys.

Thanks guys for the input! Guess I have some more shopping to do!

My '57 2 ton LCF has what I think are the original ground straps. One from the negative battery terminal to the firewall, one from low on the firewall/toe board to the bellhousing/starter bolt. I also have a negative cable from the battery to the front of the engine.

Chevy used short braided ground straps because the company bean counters took the "baby chicken" approach to electrical systems. (CHEEP- - -CHEEP- - - -CHEEP!) You'll be much better off to run a HEAVY ground cable (like #0 or bigger) from the battery to anywhere on the engine block or bell housing, and run smaller grounds (#6 or #8) from the engine to the body, frame, and bed. The starter and charging system need the most current flow- - - -everything else such as lights, heater, instruments, etc. have much lower current draw, and they can use a lighter gauge ground. Braided ground straps are notorious for getting corrosion between the braid and the end terminals and causing lots of voltage drop and low cranking speed and/or a weak spark.
Jerry

Mike...
On my 54 3100 6v I run 00 cable from battery hot to the starter and 00 from battery ground to the bellhousing. Then a regular automotive ground cable from the bellhousing to the frame and a lawn tractor ground cable from the frame to the cab.
Sounds like overkill but a 6v system lives and dies by its ground connections.
If you need the strap for authentic appearances then hide a good ground where it won't show.

Kind of like the old saying... You never have too much ammunition.

Good suggestions, especially for 6v systems. Clean them contact points as well.