Jump to content

Alternator excessively hot


Recommended Posts

Posted

Ok, I replaced my alternator this morning with a used one from my other car. I started up the car, and turned on some accessories, radio lights brake lights. Then I drove it around the block, seemed fine. I opened the hood and touched the alt. It was freaking hot, like 150*! Is that normal? Should I be worried?

Posted

It doesn't matter, soon as you get a load, heat builds even if it runs for 30 seconds.

Posted

There's no way this is normal. The thing is getting so hot in 10 minutes that if I lick my finger and touch it, it boils off instantly. I can smell it in the car. The BAT terminal seems to be loose. Could that cause the alternator to work harder?

Posted
Yes, it has to keep the engine running with no help from the battery.

 

no, your car runs off the battery, not the alt

Posted
Yes, it has to keep the engine running with no help from the battery.

 

no, your car runs off the battery, not the alt

 

A car should be able to run without a battery. The battery is just there so it buffers and stores power for when the car needs it.. like when starting the car.

 

Think about this. A carbattery is charged by what object in the car. . Ding ding ding. thats right the altinator.. the main powersource for any vehicle.

Posted

I figured out the problem. My power wire for the alt is worn out, and the alternator I chose had a bad bearing and the brushes were worn out too. I went and looked over my old Iceberg that crapped out. I figured out what was wrong with it and fixed it. When I tested it at school it was putting out 150 amps, so I threw that one on. It stays much cooler. I'm replacing the power wire tomorrow.

Posted

Sorry, but the car runs off the alternator once it is started. The sole purpose of the battery is to start the car and store voltage.

Posted
Sorry, but the car runs off the alternator once it is started. The sole purpose of the battery is to start the car and store voltage.

 

Exactly. My auto electricity textbook says precisely the same thing.

Posted
Sorry, but the car runs off the alternator once it is started. The sole purpose of the battery is to start the car and store voltage.

 

Exactly. My auto electricity textbook says precisely the same thing.

 

Also try to absorb voltage spikes/drops...

 

:shock: :D

Posted

"the car runs off the alternator once it is started. The sole purpose of the battery is to start the car and store voltage."

true that

I remember a few months back I said this and some guys tried to say I was wrong, I didnt even reply. the simplest method to test an alt is to unhook the positive off the battery and see if the alt can keep the car running. this is of course without the options running

Posted

why will a car run for a short time with a dead alt then?

 

 

the car runs off the battery, and the alt replaces power taken from the battery

Posted
why will a car run for a short time with a dead alt then?

 

 

the car runs off the battery, and the alt replaces power taken from the battery

 

Its the same reason your car will run without a battery and without an alternator if you just feed it 12 to 13.4 volts of electrical DC power. The car does not run off the alternator or the battery specifically, it runs off the power system.

 

The car won't start without a battery. With just an alternator there, there is no power, as the alternator needs to spin. However, once started, a car will run without a battery. As long as the alternator is spinning, no battery is required.

Now, start a car with a battery and no alternator...no problem. She'll start and run if it's a good battery...but in about 15 minutes...OH NO...your battery is dead. Car won't start or run anymore. As soon as the battery is dead, the electrical system is dead.

 

So, as you can see, you need both for the car to start and run correctly. Because alternators are designed to run the car and charge the battery, they provide enough power to run the car without the battery. Once a battery is charged, it consumes very little electrical power.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...