OK let’s just be clear, I am not going to tell you how to do this. There is a great video from JBugs on how to do this and it is a pain. The video is here: https://www.youtube.com/watch?v=S05pHNO7RQw
That said I will walk you through how I diagnosed it. First I drove it around and it would do if the RPMs went low.
- I hooked a voltmeter up to the battery and it was at 12.1v.
- While running the voltage from the alternator was 13.8 or 12.4v not enough to charge it
- The charging bulb was inconsistent, it would turn off once I started driving or not turn on at all.
- I could ground from the motor to the wire on top of the alternator and get the bulb to light up in the dash.
Which comes to the dash light bulb. The bulb on the left of the speedo must illuminate when the key is switched on, it should go off within 10 seconds of starting up. This is a weird circuit that shows if the power is higher on the battery or alternator side. The alternator side makes it go off, the battery side makes it light up. When the light goes off the alternator starts charging, I replaced the bulb and the socket as a precaution, but it was a bit wasted effort.
The terminal on top of the red alternator was grounded to the fan shroud to make the light come on. This ensured the circuit from the alternator to the dash was good.
I bought a Bosch alternator from JBugs. I opted for the Bosch 55W alternator: https://www.jbugs.com/product/AL82N.html .
I attempted this on my own following the Muir book and the Bentley manual and stopped.
So after I chickened out. I bugged my friend Brent who is a retired mechanic, a wizard 4th class an a hell of a nice guy. I did the install, but he showed me what to do and gave me the confidence to remove the carb, the distributor, etc. This was a bit bigger than I had ever done on a motor.
One tool that is needed is a 13mm 90° wrench, the back nut on the bottom of the carb is a real pain in the neck. This one on ebay will work: https://www.ebay.com/itm/233942721845
After replacing the alternator, everything worked perfectly. I parked next to this honda buggy on the way home.
