2 Leads to the starter motor?

**Spyda** · 19-01-2009, 11:49 PM

I have just upgraded my "Big 3" in preperation for a big sub.
The "Big 3" is upgrading the wires from the alternator to battery, battery to chassi and chassie to engine block. (in my case upgraded from what i think was 8awg to 2awg)

When i was changing over the wire from the alt to the battery i noticed and extra wire going from the alt to the starter motor AND another wire from the battery to the starter motor.

Whats the point of this wire from the alt to the startermotor? Does the starter motor have a capacitor or a storage system built in to it. I thought the battery was suposta crank the starter motor and off you go.

If there is no point to this wire from the alternator to the starter motor is it safe to remove it?

Cheers

**moto** · 20-01-2009, 12:03 PM

If its the one I'm thinking of, the wire goes: alternator -> startmotor -> battery

In other words it is a dual purpose electrical route: the live feed from the alternator to the battery and the live feed from the battery to the starter.

The connection at the starter seems to degenerate leading to voltage drop between the alternator and the battery. Rather than removing either wire (which will cause big problems) its a good idea to make sure all the connections are very good.

**Spyda** · 20-01-2009, 01:28 PM

Originally Posted by moto

If its the one I'm thinking of, the wire goes: alternator -> startmotor -> battery

In other words it is a dual purpose electrical route: the live feed from the alternator to the battery and the live feed from the battery to the starter.

The connection at the starter seems to degenerate leading to voltage drop between the alternator and the battery. Rather than removing either wire (which will cause big problems) its a good idea to make sure all the connections are very good.

Yeah you are correct.

The wire goes: Alternator -> Startmotor -> battery
BUT
There is another wire the goes: Alternator -> Battery.

I have upgraded the Alternator -> Battery wire and the Battery -> Startermotor.
I don't see the point of having a wire from the Alternator -> Startermotor when there is already a wire conecting the alternator to the battery.

Is it safe to remove it? Anyone?

**moto** · 21-01-2009, 06:33 PM

I'd guess the additional wire (alternator to battery) is a modification someone has made to overcome the voltage drop through the starter motor.You could remove it and see what happens.

**h100vw** · 21-01-2009, 06:44 PM

The standard set up is the Alt to starter and then battery.

The reason being that during cranking any output from the alternator will assist in turning the starter.

Making sure all the connections are clean and bright before replacing cables is a good idea.

Checking the voltage drop between the battery and both the alt and starter is another sensible check.

Gavin

**Spyda** · 21-01-2009, 07:55 PM

Originally Posted by h100vw

The standard set up is the Alt to starter and then battery.

The reason being that during cranking any output from the alternator will assist in turning the starter.

Making sure all the connections are clean and bright before replacing cables is a good idea.

Checking the voltage drop between the battery and both the alt and starter is another sensible check.

Gavin

Cheers.

I don't suffer from voltage drops.....yet (MUhahaha 1000rms). Good and tight cables arnt going to make hte same difference as 2awg anyway.

I just want to know if i can remove it.

**h100vw** · 21-01-2009, 08:00 PM

Originally Posted by Spyda

Cheers.

I don't suffer from voltage drops.....yet (MUhahaha 1000rms). Good and tight cables arnt going to make hte same difference as 2awg anyway.

I just want to know if i can remove it.

I'd say yes.

Gavin