Previous owner seems to have screwed up the starter/Battery wiring. The - cable from the battery is grounded to the chassis but there is another place for it to ground but I can't see where. The cable has 2 lugs.

The - cable should ground on the block.Usually up front near the fuel pump.But i relocat them to as close to the starter as i can.And having the cable also grounde to the chassis is a good idea.

On my '71 240Z the cable has two leads, one heavy and one small. The small one connects to a threaded hole on the firewall near the battery. The heavy lead connects to the upper of the two starter mounting bolts.

On my '71 240Z the cable has two leads, one heavy and one small. The small one connects to a threaded hole on the firewall near the battery. The heavy lead connects to the upper of the two starter mounting bolts.

Same as my'72.

Same on my '77 280Z.

Same as Arne, Gary and Kim.

When you connect to the firewall, try to sand down to bare metal and throw a little dielectric grease under the ring terminal when you bolt it on. Improves the connection and helps prevent future corrosion. Bad electrical ground can really drive you crazy trying to track down.

If you pefer a better looking Battery top, Run an 8 gauge wire from the same bolt as your ground wire mounting point, and connect the other end to the same point that your Engine harness is grounded. It's kinda like bolting your engine harness to the battery, but you get a cleaner look from the tranny bolt to the frame rail and along the harness to an existing ground bolt.

And just like Bart said, Fresh Grounded metal, dielectric grease and BOLT it down good an tight. then place a little more grease on the outer surface to protect it any further.

What most folks don't realize is that when you bolt your battery ground to the tranny, the engine is mounted to the frame with Rubber!!! The only real ground from the battery is the little wire from the battery clamp to the firewall, AND, that alternator ground to the engine harness and body at that one little point.

Dave

I have a good chassis ground but there is no engine ground. The cable I have will not reach so I'm headed to the parts store for a jumper.

I'm planning on bolting it to the top starter bolt. That sound good? I will run one end to the chassis ground or should I take it to the clamp?

Just run a good 4 gauge ground wire from the Neg post on the battery to the top starter bolt. And make sure it has a good lead wire on it to be bolted to the firewall near the battery. THEN run another wire (8 gauge) from the top starter bolt (bolted to the tranny) over to the ground wires on the engine harness.

That should do it.

Dave

When I replaced my battery this summer I bought a dual post battery. I used one #4 AWG cable to connect the top post of the negative side to the engine block, and a second #4 AWG cable to connect the side post of the negative side to a ground bar that I mounted on the firewall.

(I have several relay circuits that connect to ground so I needed the space.)

The ground bar was only about $3 at Lowes. It is rate to accept a #4 wire, but the opening is sized for a solid wire so a stranded #4 has to be trimmed slightly.

Just throwing out ideas.

Edited September 1, 201014 yr by Walter Moore
Corrected my grammer.

OK guys, I think we are good to go. Followed your advice..mostly. Ran the existing 2 gauge cable to the top starter bolt and also ran a 4 gauge from the top starter bolt to the chassis where the cable was connected before. Then I ran a 10 gauge wire from the neg terminal across to the engine wiring harness ground. Now the wires are not heating up during starting.

Currently the car is under plastic with a bug bomb inside and under the car. It will sit there until Thursday evening when I will add some gas and try to get it started.

Thanks and I will update Thursday