Troubleshooting Battery Drain (1 Viewer)

[Hilux]

You should have gotten a current reading from the single wire that is connected to the post on the back of the alternator. At the minimum it should have been providing the electrical energy needed to keep the truck running.

10-4. Grounded out the NEG and touched the POS to the nut on the back of the alt. and it was .2 or .3 IIRC.

Nothing on the clamp, that is if I'm even using it right...


It's got a new rebuilt/reconditioned alt on it anyway. Spotted to me by TN80...

I don't remember the name or where it even came from.

I get off work at 3, let me get a little rest in and I can walk you through it over the phone. pm me your #

10-4. OTW.

 

[KLF]

Ummmm... wrong kind of meter. Clamp meters work on AC only, not DC.

And if you do get your hands on a meter that can read DC amps, you need to put it in series in the circuit, not parallel. Think of it like a flowmeter, so it needs to be "in the flow" of the current.

 

[Hilux]

I thought so... I was trying to get one that did it all, but didn't realize till I opened it, it didn't say MultiMeter...

 

[KLF]

This is the one I carry in my "road tools" box. Does a lot for $30.

Craftsman

It's not the most accurate or durable, but at that price it won't kill you when you accidentally drive over it, or lend it to someone and they "forget" to return it.

 

[Bogo]

Ummmm... wrong kind of meter. Clamp meters work on AC only, not DC.

And if you do get your hands on a meter that can read DC amps, you need to put it in series in the circuit, not parallel. Think of it like a flowmeter, so it needs to be "in the flow" of the current.

Actually there are clamp meters that will work on DC current. They require a different clamp probe electrical design so they are usually a bit more expensive. Check to see if the meter has a DC Amps setting and read the instructions on using it.

 

[cruiser88]

i HAD a really nice dc probe before the divorce.....I thought i might have it with me but I dont

talk to ya soon, hilux

 

[Bogo]

I should get one some day. I've been using one I cobbled together a couple decades ago from a hall effect sensor and a split torus ferrite ring. It isn't very accurate, but when hooked up to a 9V battery and a DMM it will tell direction and roughly tell current amount in a wire.

 

[KLF]

Actually there are clamp meters that will work on DC current.

OK, I'll take your word for it, never seen/used one. The one I have (and the one he posted) is AC only on the clamp.

 

[cruiser88]

Sears: Online department store featuring appliances, tools, fitness equipment and more

 

[toy4xfun]

here it is klf...

i got it in a box of junk at the flea market, i should have looked at it closer, i went out to get it for a pic and the batteries exploded in it, but the fluke 77 + that was in the box works fine, after replacing both fuses!

 

[Hilux]

Anybody know a quick and easy way to test an external voltage regulator?

More than likely, it's a Diode or external regulator, right? (...more than likely)


Tested 12.77 before a start (Been sitting with the cable off). Started and running 12.4~3 with no rise in Volts.

It's got a new alt?

BTW, tested 2 other alt's I had for that truck and they ALL read bad.

A technical service bulletin that came with the alt says that plug works with other alts but is wired different.

Says if that plug is used the alt will test bad.

 

[Bogo]

If the regulator has failed it may not be providing a field voltage. The field voltage is used to provide the magnetic field against which the alternator generates its power. If it isn't providing enough current there won't be any output from the alternator. The regulator varies the amount of current going to the field coils to regulate the output of the alternator.

The Charging section of the FSM over at NCTTORA has a nice description of how to check the charging system using an inline amp meter. If you aren't getting proper output voltage/current, looks like this is your situation, they have you ground out terminal F and test gain. Read their procedure. If that still doesn't produce enough output voltage/current, then they have you check the alternator. If it goes high, then you replace the regulator.

They also mention the 4 fuses that must be good for charging to work. AM1, AM2, Engine, and Charge fuses must be good. My guess is the Charge fuse is the one that powers the voltage regulator.

http://www.ncttora.com/fsm/1985/1985FSM.pdf
I'm making the assumption you have an 85ish vehicle as you tacked your requests onto this thread.

 

[Hilux]

Damn, yeah I guess it helps to specify what I got. It's an 84 flatbed 4WD bucket of rust.


And thanks for recommending the FSM. I just upgraded internet speed and it knocked my computers out or I'da been looking at one.

I looked in my Chiltons but haven't found testing the regulator procedure yet.

 

[Bogo]

I downloaded all the FSMs onto my computer so I don't have to download them again. I just bring them up in Acrobat when I want to use them.

Here are the three pages detailing the checks and procedures. First pages is short because the bottom half is blank.

 

[Hilux]

(External) voltage regulator... (Or at least we'll see)

Bolted on one I had but not exactly like it and the batt's reading 13.9~14.

There also appeared to be moisture inside the weather connector. Maybe that was it.


Thanks Bogo...

I still think this thread belongs in the stickies