correct way to run battery cables????

I've always been told there are two ways to run you negative battery cable
1. from the negative post on the battery all the way to a starter mounting bolt or
2.from the negative post to the frame, a ground strap from the starter to the frame

whats best??
Thanks

 

Generally any part of the engine (including the starter).

 

May seem like overkill (and not so purty), but where possible, I run two, the clamped one to the engine, and a double eye one (of the same gague) through the clamp bolt to a good body source on the firewall, such as a hood hinge bolt. A pic would explain this better, sorry.

 

Grounding to the frame works fine (at least it has in all the race cars and hot rods I've built in the last 35 years). What IS important is that all grounds are clean, i.e., free of paint, grease, and corrosion. Make certain that the engine is grounded to the frame, and that the body is grounded to the frame, too (especially if you have rubber or other non-conductive body mounts). If you ground to the starter/engine area, still run a ground to the frame, and the body to the frame. What grounding to the frame really does is save having to run a ground cable from a remotely located battery (trunk, behind seat, etc.) to the engine compartment). Saves $$, andis cleaner. Just my .02 vic

 

I the battery is in the front I run the battery ground to the engine block. Also I run a heavy ground strap from the engine to the body to make sure all of the lights and accesories have a good ground. If I mount the battery in the trunk then I'll run the ground to the frame then run a ground strap from the frame to a bellhousing or starter bolt and another one from the frame to the body. Rubber engine and ****** mounts dont make good conductors.

 

By adding the 2 mechanical connections when running it to the frame, you add 2 potential places for a bad connection. I welded a stud to the frame to eliminate that...right... wrong. It gave me fits. I moved the ground cable from the frame to the tail housing bolt on the trans and the problems went away.

When I build a car I figure on keeping it for a long time. I plan on servicing it down the road. You'll get lots of people that will say a jumper ground will work just fine and it will, but will they help you clean the ground terminals when they corrode?

Neither way is "correct" but running it to the crankcase or trans case eliminates 2 potential problems. If you check the cars in the parking lot, most all of them will have the ground go dirrectly to the engine.

 

The only load that needs a "battery cable" sized ground is the starter. The more directly you ground the starter, the better.

It's not always possible, but I like to run all grounds to common posts that are in turn connected together by #12's, in other words I use wire for grounding, not depending on the ch***is at all.

 

2 ga..minimum. Ground cable to the block. I like to attach mine at one of bellhousing bolts, close to the starter. Ground strap from the motor to the frame. Smaller ground strap(s) from the firewall to the engine.

 

A good ground to the body is very important. I have seen the tube on a manual temp gage turn red hot acting as a ground from the dash to the engine due to lack of body ground cable. Brian

 

We just ground to the frame. Just be sure you got clean metal when grounding.

 

If you have the Battery in the trunk ground to the frame. Reason is voltage drop with two cables is alot higher with two cables verses one to the frame. There is resistence per foot by area and the frame is a lot bigger than a two gauge or larger cable. Just make sure the frame area is clean of rust or paint at the ground points. If the battery is up front by all means go directly to the engine as close to the starter as possible. Starting a car is the largest amp draw on a battery so the less resistence you have the faster your engine will spin and the higher voltage you will have for the ignition to fire.

 

I can tell you where NOT to connect to! When I bought my '37 the PO had the negative cable grounded at the engine to transmission bolt. Electrolysis had corroded it so bad that the bolt snapped when I tried to remove it. Then to add insult to injury I ened up cracking the ear off the trans trying to separate them.

 

Thanks for the info-I'm going to "try" and get my A started this weekend
only 37 days to the roundup

 

I guess it all depends on where your batter is. You want to run a ground cable as short as possible. so if your battery is in the trunk your best bet is to the ch***is.

 

Interesting..I was ust reading a old Rodder's Digest and a artical on grounding..Feb. 1993..Vol 12..Number 51..Anyway..If battery is in the rear, run your ground to the engine, and a ground from the engine to the frame.Got good starter action with this grounding..No hot wires..
Duane..

 

Steel (frame, uni-body) does not conduct as well as copper (battery cable). Therefore, the ultimate would be a battery cable ground to a starter bolt.

However, most rods do not see cold weather, and we tend to over-battery as it is, so a frame ground should work well.

Do NOT fail to ground the engine AND the body with auxiliary cables. Running current through universal joints WILL piss you off. If your car is tupperware, only ground if painted in a metallic color .

And, lastly, remember that any weird electrical problem in a car is usually a ground problem.

Cosmo