Ok here is my problem. I'm working on a 1984 Toyota pickup with the fuel injected 22R engine. Its my neighbors truck and i have been asked to help him fix it. His battery kept dying and i told him it was the alternator(checked with a volt meter). He was getting less than 12v while running. I disconnected the battery cable and it died. we took out the alternator and had it benched tested, they said it was bad and he got a new one on warranty. We installed it and still less than 12v. I know quite a bit about mechanics but its electrical problems that stump me. I checked the power going into the alternator through the plug and there is constant power through all 3(about 10v) and it goes up to about 12v when the key is turned on. I checked the output of the alternator and it only read 2v.weird. I checked all the grounds and they are all good. We checked all the fuses(under the hood and inside the truck) and haven't found any that were bad. We changed the voltage regulator and that didn't help. I checked for power through the disconnected alternator wire and it had voltages consistent with the battery. I tried the magnetic test on the alternator(screwdriver on the back) and it wasn't magnetic when running(that means the alternator is not working right?) He replaced his battery and i made sure all his wires had a good connection(block,body,starter,etc.)We checked to make sure the belt was tight enough. Is it possible to have gotten a bad alternator or is our problem something more serious? I'm running out of ideas!!!! Help!!
2007-11-28 08:33:30 · 9 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
Sounds like this truck has a voltage regulator separate from the alternator.
Here is some theory.
All of these use the same basic principal.
They use fused power to the one small wire and the regulator grounds the other wire.
You should have battery voltage at the big output wire, as well as the smaller ign or F wire, and ground at the other smaller R or regulator wire.
If all these are true, your alternator is bad.
Hope this helps
2007-11-28 08:50:46 · answer #1 · answered by Bert from Brandon 5 · 0⤊ 0⤋
What is the Output from The Alternator at The Regulator with Everything hooked up and the Engine Running? From the way you're talking the Regulator is Not Part of the Alternator? If this is a "New Alternator?" and everything connected Correctly and Engine running you seeing only 10v to 12v then it's Bad! Check the Ohm Readings on All Wires? "Sounds simple but then again this is to the point of "Hans-on Only" Repair so it's time for a Good Auto-Electric Shop!!
NOTE; (If You have a Charging System set up for an Alternator (Old Type) with an External Regulator, Consider you may have "The Wrong Alt?")
(Magnetic Test isn't good with an "Alternator" because unlike a Generator it's not a "Perminate Magnet")
Good Luck!
2007-11-29 00:26:52 · answer #2 · answered by sidecar0 6 · 0⤊ 0⤋
u could have got a bad alternator or the wire on the alternator have a short or a an open circuit which 12v will still show on the volts meter but their is not allot of amps going throw witch wont let the battery charge.
2007-11-28 16:51:02 · answer #3 · answered by bananaramagrl 2 · 1⤊ 0⤋
Well the first thing that popped into my mind was the alternator needs to be removed and replaced again. The other is did you need to polarize the regulator? Some of them you do others you don`t.
2007-11-28 16:41:14 · answer #4 · answered by Big Deal Maker 7 · 0⤊ 0⤋
Have you had the battery checked? And yes; it is possible to get a bad alternator but not likely. Sorry I couldn't be more help. Maybe someone with more mechanic smarts will answer you. Good luck!!
2007-11-28 16:44:40 · answer #5 · answered by fallen 4 · 0⤊ 1⤋
try the alternator battery output. this is the big red wire that goes out the alternator going to the battery it may be corroded.what happens if its corroded, once the alternator kicks in to charge it looses resistance so it will not charge. i hope it helps.
2007-11-28 16:57:54 · answer #6 · answered by noelsans 2 · 1⤊ 0⤋
We are not going to ask where that alt. is from.Take it back and test.Always,( if available)TEST before you go to install.From exp w/ nnnnnnNINE IN one town found not one to be good.I installed two first,And checked every part on a truck twice before this.
2007-11-28 23:19:46 · answer #7 · answered by Ronnie Wrench 4 · 0⤊ 1⤋
Voltage regulator could be internal(inside alternator) or external(standalone box).Witch one is your case?If it's external,I think you should replace it.
2007-11-28 16:50:46 · answer #8 · answered by polkan47 4 · 0⤊ 0⤋
"new" alternator stuffed?
there should be a diode pack on the rear of the alternator which could be rs, get it tested
2007-11-28 16:42:04 · answer #9 · answered by Anonymous · 1⤊ 0⤋