Quite a few posts are up about voltage regulator problems so I'll add mine. I've had an ongoing alternator/voltage regulator problem resulting in a run down battery in my '76 FJ 40. Whenever I drove for more than an hour or so and ran anything that draws a lot of amps such as the a/c or lights the ammeter would go way over to the left. If I turned off the engine it wouldn't start again. So I had the alternator tested in car at my local parts store, and the readout said "low diode output". I replaced the alternator but still had the same problem, so I put in a new voltage regulator too. Now the car won't start at all. Turn the key, and it just goes click. The lights on the dashboard don't come on and the engine doesn't turn over. The battery is fine, everything else electrical works, and all the wires are good with clean and tight connections. Starter is new. Some additional info. When I took out the old alternator, I discovered that the group of wires connected to it were crammed against the battery tray, and one of them was frayed and broken which I spliced and taped back together. My truck has electronic ignition (Toyota mini-truck, I think) installed by PO. Could a short from the frayed wire have fried it? Is there an inline fuse just for the ignition? I checked the fuse in the fuse panel and it's good. Both alternator and voltage regulator came from Cool Cruisers, and they're aftermarket, but similar if not exactly the same as to what was installed before. Voltage regulator is for 1978 and later models as was old one. I need help!