FullBlowncustoms
I'm Awesome
Yeah I was talking about the single BROWN, like my 95, I just assumed he would know the Red output...
Quick questions on my '94 Alternator
- Thread starter jdjonesdr
- Start date
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HotWheelsBurban
Gotta have 4 doors..... Rawhide, TOTY 2023!
Yup I've "rebuilt" a few of those like that, on the bench in our parts store, in the '80s. The regulator, brushes, and diode trio were about all that went out on those 10SI units, and all were easily replaced once it was apart. Just remember to mark the case so you "clock" it correctly....
454cid
Sooper Pooper
I use a straw from WD40 or whatever. I pulled apart a 10dn and a 10 or 12si and had fun doing it.
Many moons ago, I had posted in a jeep group how to to replace these components using a paper clip...good old days LOL.
In my past life I used to rebuild alternators for a living. it should be putting out 14.5 (ideally) 13.x (or so) when the ac is on, 12v sounds like a deader. I have had bad batteries prevent alternators from working correctly but you are running a new battery. Swap the alternator and you are probably good.
Out of curiosity, what is the correct method for checking if I have a parasitic draw on the battery?
Do I check ohms by disconnecting the negative pole on the battery and measuring positive to ground?
Do I check ohms by disconnecting the negative pole on the battery and measuring positive to ground?
No. Parasitic draw is tested using a low-amps ammeter. Generally, this would be the ammeter section of a multimeter, typically rated for ~10 amps DC, and protected by a very expensive and uncommon fuse internal to the multimeter. With the ammeter set to read 10 amps maximum, test leads in the proper sockets of the ammeter (generally the red lead is swapped from the usual socket to the ammeter socket, the black lead staying in the "Common" socket) one of the battery cables is disconnected from it's terminal on the battery. (Doors shut, ignition and electrical accessories such as lights turned off) Can be the positive or the negative cable. If positive, the red lead is connected to the battery + terminal, the negative lead connected to the loose end of the + battery cable. The meter needs to be watched for awhile--long enough for the computer and other electrical drains to "go to sleep"--perhaps one minute, usually less. The reading is taken then.
Fancier, more "user friendly" ammeters have a clamp-on inductive lead. No need to disconnect the battery, the lead is merely clamped around the cable. Again, doors shut, ignition and accessories turned off, and enough time allotted for the computer to go to sleep.
If in doubt, follow the directions given by the meter manufacturer.
Older cars with mechanical clocks driven by an electric motor would "pulse" current draw--the motor would draw power for a second or two, which wound the main spring in the clock. Then the draw would end. The clock would run off the mainspring until the mainspring wound-down--and then the motor would wind the mainspring again.
Similarly, modern cars may leave "courtesy" lighting on for several seconds--maybe minutes--after you shut everything off. This power drain has to be allowed to turn off before your meter reading is valid.
Lower amperage draw is better. Old cars with no computer or electronic clocks could have "ZERO" amperage draw. Modern cars need some power for "keep-alive" memory in various computer modules, or other electronic devices. So you'd need to confirm the allowed drain with factory specs--but certainly less than one amp, usually less than half-an-amp, and perhaps less than 1/10 amp.
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Gotcha! The truck always sits with the ground cable disconnected, so I'll get a reading from the ground cable to the positive cable.
If it gives me a 0.00 reading I have a problem.
Going from the ground cable to the positive cable will not work.
Go from the ground cable, to the negative battery terminal.
If he's doing an ohms check, reading from the ground cable to the positive cable would work, but in my experience ohms checks are minimally informative. You are correct that doing a voltage check from the ground cable to the negative battery terminal would work, and that's the better method.
When checking for parasitic draw, I strongly prefer using a test light with an incandescent bulb.
When checking for parasitic draw, I strongly prefer using a test light with an incandescent bulb.
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