Okay done the search feature read all the articles I could and I still have an issue with my charging system.

82 22R no mods.

Started out with an overcharging issue so I switched voltage regulators. Picked up replacement from NAPA because the Toyota replacement is about 100.00. So I plug it in and immediately I go to an undercharging situation. I think my alternator has fried out so I switch it with a replacement from Autozone (because I have a warranty). Still have an undercharging situation with the second alternator. Try another voltage regulator and have the 2nd alternator bench tested. Bench tests fine and the other regulator has no effect on the lack of proper charging voltage. New battery and battery cables + and - still no joy. All the wiring and connections appear solid and questionable connections have been redone. I am missing a couple of fusable links the two off the battery and the one off of the alternator could this be the issue? Also if anyone has the part numbers for these that would be great. I have followed the test from my FSM and no definitive answers so.....
.....do I order an alternator from Toyota and try that or where else do I look for the possible answer? It is a parasitic dram on the battery, slowly dropping about a hundredth of a volt at idle and drops a couple of a hundredths revving the motor up. With fan and headlights the reading at the battery is below 12 somewhere in the range of 11.50 and dropping. So gurus I am at a loss.

Runs fine until the draw becomes too much on the battery no other issues than this electrical gremlin.

Long time reader first time poster, really enjoy the site lots of good info friendly crowd. Thanks folks.

What is your voltage across the battery terminal with engine running. Should be around 14.5v.

What I'm getting at.... It sounds to me you have no connection between the alt. bat. terminal and battery. In other words the altinator is working but the electricity can't get to the battery. Run a jumper wire from the alt bat. terminal to the battery and see what happens (make sure jumper wire is a big enough gauge or you will fry it).

Been there done that,I whent through 3 or 4 alt and regulators,bench tested,bypassed fuse links,strait wired to no avail.My 84 was overcharging (very bright headlights) so I ended putting a gm alt out of an 80's truck-works great.All you have to do cut bottom bracket of the gm alt (the one the long bolt goes through)to match the toy alt then I took a MR Gasket aftermarket alt bracket and cut it to the correct length.Then you have to convert the gm alt to a one wire set up ,there are some posts on how to do it.I also replaced the main charging wire going to the battery from the large post on the back of the alt.It sounds like alot but it's realy not that hard, mine has been going for two years without a problem.

I know I might have to eventually upgrade, modify, or change my set up but I want to go through and try to solve the problem, find out what is wrong before I cover it up.

I will however start thinking seriously about the gm mod.

If the weather wasn't my enemy this week (ice and extreme cold) it would have probably already been solved, probably.

Thanks guys.... <img src="/forums/images/graemlins/kewl.gif" alt="" />

Stick an ammeter between the + post of your battery and the + cable, should be a very low reading if any at all depending on wat you have in ur truck. I leave my CB on all the time

There are only 3 things to go wrong.
The alternator is bad (but it tests OK?)
The regulator is bad (but it tests OK?)
The wiring that connects the alternator to the regulator & to the rest of the system is bad. (no way you've checked it all <img src="/forums/images/graemlins/wink.gif" alt="" /> )


Assuming the bench tests were done properly:
If the battery is dropping below 12 volts with the engine running:
1- check the voltage at the alternator B+ terminal. If it's normal, your wiring between the alt & battery is defective.

Try using your jumper cables to connect some metal near the Alt to battery neg & see if that helps. Then try the B+ terminal to positive. BE CAREFUL! don't short anything out while you are testing.

2-check the voltage at the alternator B+ terminal. If it's *not* normal, your wiring between the alt & regulator is defective.(assuming external regulator on an 82?)

Use an ohm meter (engine off) to check each wire between the regulator & alternator for continuity.

If those tests fail to find the problem, you now know not to trust whoever did the bench test. There are only so many possible problems in a charging system, & most of them are in the alternator or regulator....

Dave

Well as an update not that anyone is following this thread besides me, I have followed the tests in the Factory Service Manual and everything seemed to check fine but I will run through what [color:"red"]Davepet[/color] suggested tomorrow when it gets back from the muffler shop. I went ahead and ordered a Toyota alternator so we will see if that makes a difference or not (my bet is no but I had to try). The bench test was done by a friend and it tested okay but just barely okay kind of on the low end.

Two different (new) regulators gave the same readings.

I hope to have it going strong tomorrow 5-10 inches of snow headed this way.

Thanks again.

Okay I guess here is my plug for buying an alternator from Toyota.

As opposed to my Autozone alternator the Toyota unit had a bigger body and a little different fan/fin/pulley.

Autozone unit had apparently gone bad and was allowing the battery to be drained and the rate of about a slow hundredth of a volt at idle and fast idle increased drain.

Toyota unit shows across the battery above 13 volts at idle and 12.6 with accessories and increases with engine revs.

So I guess I was lucky. All this cost me was about 300. New alternator, new battery, new cables. New battery was needed for the car anyway so I upgraded the car's battery to a sealed battery and was using it to perform checks.

Thanks for the help and hopefully I will be able to contribute. <img src="/forums/images/graemlins/smile.gif" alt="" />