Questions and Answers

Volkswagen Bus Auxiliary Battery Q. My dad and I are trying to install an auxiliary battery in order to run a stereo, and lights and plug ins at night. We have a 90 amp, three terminal isolator, the alternator is 55 amps, and we know how to install it, but the only problem is that we can't find the charge wire between the alternator and the existing battery.

We've searched extensively through the three manuals I own, and can't seem to find a wiring diagram to solve our problem. We've tapped into a few wires with a test light, with no luck in finding which wire charges the battery. We think it's the heavy red wire running between the alternator and the starter, but the test light lights only momentarily when the starter is engaged. Can you help us?

• 1972 Volkswagen Bus Type II
• 1700cc engine
• Manual transmission

Thanks for your time!

A. I don't have a wiring diagram I can share with you, but you can probably get one at the local Public Library in the Reference Section. If they don't have it they can get it for you.

I did something similar in my youth. I had a Ford Country Squire station wagon that I put a bed in back with mood lights and an AM/FM 8-track stereo system. Hey, I was a young pup at that time! Every Saturday night I went and sowed some wild oats and every Sunday morning I went to church and prayed for a crop failure.

What I did was install a second battery in the back, who needs a spare tire anyway, and ran two 8-gauge wires from the positive and negative posts of the car battery back to the auxiliary battery.

I used a simple double pole double throw toggle switch to isolate the battery when the engine wasn't running. When I was driving, I turned the switch ON and let it charge. When I was, ahem, doing my thing I turned the switch off.