The value of an ALT/BAT switch

[cranetruck]

Constantly in search for low cost projects to keep me busy, being able to switch off the alternator entered my mind. Particularly useful when a truck like the deuce can run without batteries.
Case in point, when we picked up my son's deuce last year from GL, it had no batteries, but was jump started with external batteries. When the jumpers were removed, the alternator regulator instantly gave up the ghost.
If there had been an "ALT/BAT" switch on the dash, the field to the alternator could have been switched off, saving the alternator.

Yesterday, I installed such a switch on the 8x8, I have another reason for it also, with the (remote) possibility of a thermal runaway in one of the NiCd cells, I want to be able to switch off the alternator to terminate it (the thermal runaway).

 

[orren]

Good idea. Also, might be useful when fording just in case the alternator doesn't
like salty or dirty water.

 

[gimpyrobb]

I put a switch between my batteries and frame ground, and found it a wonderful tool. I might have to add an alt switch too.

 

[cranetruck]

I put a switch between my batteries and frame ground, and found it a wonderful tool. I might have to add an alt switch too.

Switching batteries and/or alternator off and on may create regulator failure under the "right" circumstances.
The alternator is always "on" after the accessory switch has been turned on and can be turned off with the engine running using that same accessory switch.
In the scenario in the OP (deuce picked up from GL..), the accessory switch could have been used to save the alternator...just an afterthought...

My "ALT/BAT" switch only adds the option of turning off the alternator by itself and still have battery power to fuel pump, instruments etc.

 

[gimpyrobb]

I understand, I use my switch for when I work on the truck and need to disconnect the batts, I just twist the switch. Same for leaving the truck on display, truck no start. Each switch will have a different purpose.

 

[NightOwl]

I had a battery switch installed by Dave Newman's guys up in Philly at Eastern Supply. It works great. I use it to prevent theft and to keep from draining the batteries by mistake. I keep a coke can over it to make it harder to find. The pre-heater is the only thing not connected to the switch. My