My Generator Caught on Fire

My Autolite 7004 generator started smoking then caught on fire while the engine was just turned off and the key removed. I noticed the amp light was lit and would not go off. By the time I was able to remove the battery terminal, the wires from the generator looked like a cannon fuse working its way up towards the firewall. I managed to stop it at the junction where it branches off to the starter solenoid where it too burnt those wires. I've ordered a rebuilt replacement from Carl @ Walck's along with a new voltage regulator, starter solenoid and ignition switch which is due here any day now. I have mixed feelings that the generator was unable to handle the newly rebuilt F-134 engine and transmission at highway speeds of 55 to 60 mph. It is a 12 volt system on my 1960 CJ5. What could have caused this? I do not need a repeat on these new parts. The starter and generator were checked out while the engine and transmission were being rebuilt and both passed. Can these speeds affect the performance of these generators or was it just a fluke on a 50 year old generator? Was it the voltage regulator (new & matched) that caused this? Perhaps a worn ignition switch? It is fairly new also...Where can I find an excellent, readable wiring diagram that shows the proper connections to and from these units? The red wires to and from the voltage regulator were mostly affected and were the cause of the other wires being destroyed along the way. I have not opened the voltage regulator as of yet...

Anyone ever had this problem before?

 

the generator shorted out somewhere inside. nothing to do with speed. internal failure.

 

It was going to ground somewhere--which is why amp was lite. Current was going somewhere. I had the same thing happen on my Holiday Rambler motorhome. Wire had worn thru and was touching metal-flames ensued. It no longer has an amp meter. It has a voltage meter.

 

yep I vote it was the regulator that dun it . magic smoke . is that like invisible electricy

 

There is a right way and a not-so-right way to install the cutoff switch. The right way is to put the switch on the "-" ground side, as close to the battery as practical. Since DC current flows from negative to positive a switch on the negative de-energizes the entire system. I installed one inside the glove box -- used double 00 welding wire for cables 'cause it is so flexible. That is my favorite installation. I have four jeeps, and half a dozen military surplus generators, and all the ones that have batteries installed have cutoff switches installed somewhere on them.

I have used two kinds of cutoff switches, but the ones I like the best are the ones that have an orange "T" handle and are spring loaded so that when the switch is closed it is held nice and tight because of the springs. Harbor Freight has these orange switches if you are looking for a source.

You'll find yourself using those switches more often than you might think. Almost any time I'm working under the hood I have the switch in the OFF position, and I always leave the switches OFF when I'm done using the jeep for the day.

Regarding your original short problem... Outside of the generator / regulator / starter hardware, the only thing that could draw that much current would be the horn. Anything else in the system wouldn't cause that kind of fire since those 10/12/14/16 gauge wires would act like fuses if that much current were passing through them.

There is always a lot of discussion about voltage meters vs ammeters. I like ammeters to measure the health of the charging system. A dead 12 volt battery will still read 12 volts across the terminals. Put a load on it to try to draw current and the voltage will drop to near zero. The voltage supplies the "push", and the current does the work.

 

Well clearly they are two different things. I still believe if he was getting a reading it indicates a current flow. In my RV I'm sure it was completing the circuit and traveling back thru the chassis ground to the battery. I didn't see what the gauge said as I was under the hood at the time and quickly disconnected the battery. The big bash against an amp meter is that you are putting full current thru that gauge in the dash. I'm sure that's why people tend to remove them. Amp gauge is a tell of the charging system. Voltage the battery system. I'm not sure why my RV had an amp gauge honestly. It had an alternator not a generator as it is newer. If you have low voltage then clearly it's not charging the battery. With all that said all my willys have amp meters.