Alternator troubles

[P72Ford]

Now I know I have a problem with my alternator...

For the longest time the headlights used to pulsate when the car was stopped at a light. The volts use to bounce around (visible on the gauge).

I changed the voltage reg last week (external 100 amp) and this problem was rectified.

Sunday I added an electric fan with a prewired kit. Tested the fan, and everything was fine. Drove home 10 miles with the fan on with no ill effects.

This morning I was bored so i decided to wash under the hood. I washed the alternator really well (I scrubbed it with a scotchbrite).

I started the car and the alternator was not working. The volts were way down, but the idiot light wasn't on. I revved it to 3k rpm, and the volts came up. I got onto the highway going to get gas with the AC on and the new fan on. The alternator cut out, and the light came on. I nailed it and nothing happened. I get off the highway, and the volts come back up and the light goes out. Happened about 3 times on the way home.

What the fuck is wrong? Is it because I got it wet? Is it ruined? Could the fan or new regulator be causing this. The regaulator plugs in like it is the right one, and I can't really see it being wrong. Also, the alternator was hot to the touch when I got home. Is this normal? The VR was hot too. Normal?

Thanks in advance for any ideas/ insight.

[86VickyLX]

No it's not normal for it to be too hot to touch. When I washed my Alternator, while cleaning the engine bay, my alternator worked fine. Now the next day, my battery was completely dead, and when I went to start it (jumper box), the alternator began to smoke. It was too hot to touch, so I disconnected it and luckily, I caught it before it caught on fire. I'd say time for a new alternator.

[P72Ford]

Well, its been like 6 hours, and there have been no problems. I started it and drove it about 10 miles and the alternator was working fine. When I got back it was warm, but not too hot to touch. I would assume this heat is as a result of engine heat.

WTF is going on? Should I be carrying a fire extinguisher with me? Safe to use?

I have two more cop car alternators that are supposedly good. Should I wait and see or swap one on now?

Also, the two I have are both 100A, but they have different part numbers, yet look identical (from casting to plugs). Any insight on this? One has the same PN as my current one, but it looks like shit. I'd rather use the one that looks new, but it has a different number, both are motorcraft.

[turbo2256b]

You might have gotten some water in a conection or dirt and some scotch brite in the brushes or such when cleaning it. Could even blow some compresed air into the case. Might do some good if it persists.

[86VickyLX]

Well, its been like 6 hours, and there have been no problems. I started it and drove it about 10 miles and the alternator was working fine. When I got back it was warm, but not too hot to touch. I would assume this heat is as a result of engine heat.

WTF is going on? Should I be carrying a fire extinguisher with me? Safe to use?

I have two more cop car alternators that are supposedly good. Should I wait and see or swap one on now?

Also, the two I have are both 100A, but they have different part numbers, yet look identical (from casting to plugs). Any insight on this? One has the same PN as my current one, but it looks like shit. I'd rather use the one that looks new, but it has a different number, both are motorcraft.

I would say the newer looking one was remanufatured?? Not sure. I'd carry a fire extinguisher even if there was no problem. I'd change it. Why push your luck. The alternators can get warm yeah, but if they're too hot to touch, I still say time for another one.

[85crownHPP]

Its generally not a good idea to let water/solvent/dirt get inside electrical parts... alternators can survive a splash but scrubbing on them might your ill effect.
Id only use something like a pre-moisted degreaser wipe and a little polish on a cloth, to avoid drips when cleaning an alternator.

[86GmLsCoupe]

I'd cover it it just like the distributor, throw a plastic bag over it next time you wash the engine. Fire extinguishers are a very good idea for the car.