Battery wire gauge mis match . ok?

[gdizzle]

I am replacing battery cables, was able to replace the Ground side without issue. However the hot side currently has 4g heading directly to starter, but also has a 8g heading to the starter relay (mounted on the firewall).
The issue is buying a replacement cable, has the 4g, then has a pig-tail which is only 10g.

Is it safe/acceptable to run a 10g wire to the starter relay, instead of the current 8g?
Or is it safe to use my current 8g (old)wire, cut it and splice it to the 10g pig-tail from the battery terminal?

 

[71Scamper]

I am replacing battery cables, was able to replace the Ground side without issue. However the hot side currently has 4g heading directly to starter, but also has a 8g heading to the starter relay (mounted on the firewall).
The issue is buying a replacement cable, has the 4g, then has a pig-tail which is only 10g.

Is it safe/acceptable to run a 10g wire to the starter relay, instead of the current 8g?
Or is it safe to use my current 8g (old)wire, cut it and splice it to the 10g pig-tail from the battery terminal?

run the replacement wire. You have to remember that the standards today for wiring is better than the 70's and also the quality of the copper alone is better as well. Also, that 8g wire only sends power down to the starter solenoid that throws out the starter pinion gear. It's not a lot of amperage to make that plunger move.

 

[Pete in NH]

You didn't mention what car this is on but, many times the entire electrical load current for the car flows through this wire, not just the starter solenoid current. I would prefer to keep it the 8 gauge wire. I would get a new piece of 8 gauge and crimp the proper size ring terminals on each end. Connect one end to the starter relay battery stud and the other directly under the clamp bolt of the positive battery terminal. That way you have a straight run of new wire with no splices, which can be a problem if not done right at high currents.

 

[jos51700]

I always wire the entire car with red 0g just to be safe. Even my Dr Crankenstein AM/FM cassette radio.

 

[67Dart273]

run the replacement wire. You have to remember that the standards today for wiring is better than the 70's and also the quality of the copper alone is better as well. Also, that 8g wire only sends power down to the starter solenoid that throws out the starter pinion gear. It's not a lot of amperage to make that plunger move.

If believe this is incorrect. I believe he's talking about the STARTER cable from battery to starter and then the main supply from the starter "big stud" back up to the relay battery stud, IE power supply for 'rest of the car' and also charging wire from alternator.

easiest way to deal with this is buy a "ring to ring" starter cable of appropriate length, and run from starter back up to relay.


Copper is better in modern times? Not sure I believe that, either.

 

[gdizzle]

Sorry for confusion, this is on the 66 dd running 6 slanted pistons.
the current wire it old. It goes from my battery + direct to the starter. Then there is also a pigtail, actually it is just a smaller gauge wire that has been mashed in with the Starter wire and screwed down at the battery terminal. This smaller gauge is 8g, it heads directly to the firewall-mounted relay lug, where it site beneath 2 other ring connections. So I assume everything is running through this wire when the car is running? Maybe I can find a new battery terminal that will allow for 2 connections? one for the 4g and the other for the 8g? Then I can just buy new 8g wire and run it and crimp on a new ring connector for the relay.?
I have not seen this type of terminal at my local stores, though.

 

[71Scamper]

If believe this is incorrect. I believe he's talking about the STARTER cable from battery to starter and then the main supply from the starter "big stud" back up to the relay battery stud, IE power supply for 'rest of the car' and also charging wire from alternator.

easiest way to deal with this is buy a "ring to ring" starter cable of appropriate length, and run from starter back up to relay.


Copper is better in modern times? Not sure I believe that, either.

I read it wrong. I thought he was talking about the wire from the safety solenoid to the starter solenoid.

Yes believe it or not, copper wire today is far better quality than that of the 60's/70's. I bet if he compared the strand size and quantity the newer wire would still have more stands. The electrons flow on the outside of the copper wire. This is why welders run fine stand wire, handles far more current than large stranded wire.

To the OP, if you have any upgrades or extra loads on your electrical system run the same gauge wire as before. The newer wire will handle more load than your previous. Just a little insurance.

 

[67Dart273]

. The electrons flow on the outside of the copper wire..

This is only true for AC, and higher frequency AC. It's known as skin effect, and has no bearing for DC circuits. As a radio amateur, I'm well aware of skin effect