Alternator???

[bluecollar]

About a week ago both batteries died on my truck so I got autozone to check it out and alternator tested bad. Put the new one in (rebuilt 100 amp) and decided to go ahead and replace voltage regulator too and all seemed well till the next day. Been through three different regulators from Advance and today the 4th from Napa. I've never encountered this before but I'm guessing the alternator is bad and destroying the regulator? Has anybody had this happen? The regulator will get hot and the voltage guage will start climbing with the rpm's untill it finaly ends up at max. Had to turn the headlights off from fear of blowing them and the heater fan was really spinning till I shut it down too.

 

[tonkadoctor]

I've seen rebuilt alternators go bad in a day & I saw some people come back 2 or 3 times in a couple weeks to replace alternators too.

I'll just say I don't work for or buy electrical stuff from Manny, Mo & Mack anymore.

Now, over charging is usually the fault of the regulator failing, however it can be caused by wiring problems too. Double check the wiring from the alternator to the external regulator and make sure the wiring is hooked up to the alternator correctly. I can't find my scematics right now but there is one wire that has to be hooked properly to the "S" terminal or the alternator won't know how much voltage to supply and when to stop...thus resulting in overcharging, dead batteries, boiling batteries and exploding batteries

 

[bluecollar]

Thanks for the reply. I don't see but one way to hook the regulator up. It's just a simple plug with one small ground wire that connects under one of the mounting screws. The alternator itself is pretty straight-forward as far as installing. Could the alternator cause this because I'm thinking about swapping this for another. It happens after it's warmed up and been running a while

 

[Neal J. Moran]

If you haven't solved the charging problem, I'd be happy to walk you through it. I'm an electrical rebuilder.

 

[bluecollar]

The problem is still occurring. Truck has been fine with no electrical problems at all. Abouth a week ago I went to leave work and wouldn't start so I got a jump and realized on the way home it wasn't charging. Took the alternator off and Autozone checked and confirmed it was bad so I bought a remanufactured 100 amp. I fugured I would go ahead and buy a new regulator too and replaced all the belts while I had the time. It was an easy job with no problems. Run the truck a day and voltage gets to where it's going up and down with engine rpm. Thought I had bad regulators so swapped three with advance auto parts and finally yesterday bought one from Napa. All four do the same thing after truck has been run a while it just all of a sudden starts doing this. The regulators are all hot to the touch when this starts happening.

 

[icanfixall]

I deal with a small alt starter rebuild shop. They told me to disconnect the batteries before I install the voltage regulator and to make sure I have it well grounded before power is introduced to it. I had some v-r failures till they told me about this. Its worked fine ever since.

 

[Agnem]

I just got a rebuilt alternator and new voltage regulator and pigtail from Ford. Even thought the VR was chinese Motorcraft, I had no problems. I still think Ford has better quality control on their aftermarket parts.

 

[Mr_Roboto]

It really sounds like a wiring problem. Maybe a broken wire, maybe a wire shorted out. Why else could you put different "new" components on and get the same thing happening with all of them?

You could always take the "3G" pill. Internal regulator, simplified wiring, more reliable big power. See my post in the tech articles.

 

[sle2115]

You might try a different brand. I would look for somewhere that sold standard ignition.

 

[bluecollar]

Well I took the alternator back and exchanged it for another today and drove it a while and all is well so far. I plan on driving the truck to work tomorrow and I'll get a chance to warm it up real good. I sure hope I'm right but I think that alternator was just putting out too much when it got hot. I really appreciate you guys helping out and I sure respect yall 's knowledge. I'll let everybody know how it goes.