Alternators

[Rranger]

I bought this. http://www.motorcityreman.com/deoe1111111136.html. Installed it on my 5.7L engine. Seller told me you hook one wire direct to positive on battery. No other wires including no ground. Did that and alternator gauge is in the red. Anyone else used one of these one wire units? Will be going to mechanics next week and he will test voltage but curious about other posters experience's with this. Thanks.

 

[alldodge]

I bought this. http://www.motorcityreman.com/deoe1111111136.html. Installed it on my 5.7L engine. Seller told me you hook one wire direct to positive on battery. No other wires including no ground. Did that and alternator gauge is in the red. Anyone else used one of these one wire units? Will be going to mechanics next week and he will test voltage but curious about other posters experience's with this. Thanks.

Just so we get a square footing before answering;
What year is the engine
Has there been any modifications done like, isolators, ACR, battery charger or other rewiring?
Did you use the original harness ALT wire or add another, if you added another where was it connected?

 

[Rranger]

88 engine, perko 2 battery switch is all. I added another wire from the alt to the battery. The old wires going to the old alternater are not being used.

 

[alldodge]

88 engine, perko 2 battery switch is all. I added another wire from the alt to the battery. The old wires going to the old alternater are not being used.

You should use the old ALT output wire, or if to small run another back to the starter post. From the starter post it goes back to your Perko switch. Doing it this way no matter which battery you have selected it will charge and (the important part) sense the battery state. Not seeing your wiring, I'm thinking the ALT is sensing the battery not connected so the voltage sky rockets.

The other two wires which went to the ALT (small purple and Purple/Red) will no longer be used.

The wire going to the starter post should be at least 10AWG. Now if the common post of your Perko switch does not go to the starter post this also needs to be fixed

 

[Rranger]

I've got two batteries one positive to perko battery one. Second battery positive to perko battery two. Starter cable from starter to perko common. I have another wire going back to starter already. I'd have to look tomorrow to see what color I believe it's purple with yellow stripe. It's Always live.
I have a red wire in the old alternator cluster that is live and wonder if that one should have gone to the starter?
Are you saying I need to run another smaller cable from the starter to the common or does the starter cable from the common on the perko to the starter do the job?

 

[alldodge]

the starter cable from the common on the perko to the starter do the job?

The cable already there will do the job

The wire coming from the ALT to starter is Orange