starter fusible link

[Mark Maras]

A friend and I just ran into the oddity of the 1955 Packard using 12 volts and positive ground a few months back on his Packard Patrician. That one threw both of us into confusion until we dug deeper.

[SteveJ]

I once helped a young man who was trying to fix his 280ZX after he attempted to jump start his car with his father's Sunbeam Alpine. That young man quickly learned the hazards of connecting jumper cables to ground when one of the cars is positive ground. 

[Wally]

There are no letters on back of my alternator (at least i dont see any)

Before i cut the wire to add a new larger diameter connector for the B terminal let me make sure i understand. 

1) image 2793, its the "ground" and has 2 wires connected to it, one of which is the condensor body?

2) image 2795 is the wire coming of the condensor (with the fork) it goes to this "B terminal" for total of 2 wires there?

3) This wrong hookup....its likely its what burned up the fusible link on starter?

 

Steve, dont worry, i can 100% guarantee i will make another bonehead move...probably soon too.

[SteveJ]

56 minutes ago, Wally said:

There are no letters on back of my alternator (at least i dont see any)

Before i cut the wire to add a new larger diameter connector for the B terminal let me make sure i understand. 

1) image 2793, its the "ground" and has 2 wires connected to it, one of which is the condensor body?

2) image 2795 is the wire coming of the condensor (with the fork) it goes to this "B terminal" for total of 2 wires there?

3) This wrong hookup....its likely its what burned up the fusible link on starter?

 

Steve, dont worry, i can 100% guarantee i will make another bonehead move...probably soon too.

 

 

1. The condensor body does not have a wire. It has a metal bracket that bolts to the case of the alternator. In your photo, the ground wire is bolted to the case at the same point.
2. Yes, the wire coming out of the condensor goes to the B terminal of the alternator along with the white/red wire.
3. The black wire at the alternator is the ground for the alternator case. When you attached the white/red wire to the alternator case, you grounded it. That wire goes to the ammeter gauge, and there is a white wire on the other side of the ammeter gauge is a white wire. That goes down to the fusible link. I did a simplified diagram below. If the white/red wire is attached to the B terminal, it is not grounded to the case of the alternator.

[Wally]

Roger that. will an upgraded alternator cause an issue with the ammeter. I believe the gauge goes up to 45 and the new alternator ideally puts out 70+

[grannyknot]

6 hours ago, Wally said:

Roger that. will an upgraded alternator cause an issue with the ammeter. I believe the gauge goes up to 45 and the new alternator ideally puts out 70+

It may put out 70 amps but only if there is a 70amp draw, if your Z is basically stock you won't exceed the 45 setting and if it does it will just peg the needle until the draw changes.

[RJK]

Wally-your new alternator looks to be the same design as the one I have, from ZCarDepot.

I feel compelled to reiterate this: I also connected the + wire of the car to the ground of the alternator. Luckily, your fusible link worked; on mine, the wire maintained integrity, and burned off the insulation. The rub there: I think it's highly likely I have a short on the +wire to alternator that is hidden in the wire wrap. This seems to be a pretty serious safety hazard, especially if a fusible link doesn't blow. If I were you, knowing you definitely put those wires under a similar duress I put mine under, I'd check the sheathing on your alternator + and ground wires, at least with a DVM. (can anyone report back what an ideal impedance reading would be from battery harness + to alternator wire ground?)