erratic voltage reading with temp and speed on m1009

[dmilkman589]

did a 2 day off roading expedition and i had a solid voltage reading. then had a solid voltage reading the whole drive home... i drove to buffalo today from albany to go back to school and the entire way here my volt meter was hovering around high yellow, low green. but if i slowed down and shut all the power off it will creep back up too higher green, never reaching full green. it appears when i drive fast the volt meter drops. or when its cold outside the volt meter drops. does this sound like corrosion, or a bad alt, or something else?

this is on a m1009

 

[dmilkman589]

o and the lights are dim and the windshield wipers are really slow when this meter is showing the low reading. but if i turn other stuff off and drive slow the wipers will go faster...

 

[twomorestrokes]

My 1008 started doing the same thing. Always cranks fine and drives fine at night, but gauge usually stays at the top of the yellow segment now, rarely going into the green. It used to run in the green all of the time a couple months back.

I don't notice the lights dimming on my truck, and the wipers are always slow because the motor needs replacement. The only issue I notice is the gauge is lower than it used to be.

 

[dmilkman589]

o and the gen 1 light comes on about half bright as this is happening.

 

[twomorestrokes]

Oh, okay. I don't have that bad of trouble on mine. Never a gen light and I don't even know if the gen 2 light even works. It does not glow with key on, engine off even with a different bulb.

 

[dmilkman589]

i can narrow down the symptoms now. i started the truck this morning to drive to school. 11 volts at front battery. drove the entire way to school highway driving, 11 volts. i got to school. parked it. and let it idle. the voltage then began to creep up to 13. so it appears this charging problem gets worse in the cold. never really reaching higher than 13 unless its idle or slightly above idle for a while. its really low when cold and first started. and appears that voltage decreases with highway speed of engine. what could this be? if in alternator, can i get by with the cheap rebuild kit from cucv electric. im 300 miles from home so i have limited tools. so if i can by id like to get the cheap kit.

 

[twomorestrokes]

Silly question, but how is the belt?

 

[dmilkman589]

its fine

 

[Barrman]

Besides checking the belt for tightness. Check the nut on the front of the alternator shaft. It could be loose and the pulley is just free wheeling when you rev the engine. Otherwise, it is probably time for a take down and put new innards in there. You really only need a 15MM wrench to get the alternator off. Along with taking the wires off. Then, a cheap 1/4" ratchet set will do all you need for working on the inside.

 

[Dr.Jay]

You can purchase all of the parts to rebuild the alternator, at any auto parts store. The alternator has the same internal components as one for a 1978 Cadillac Sedan De-ville with multi port fuel injection.

Tools You will need:
3/8 drive ratchet
6 inch long 3/8 drive extension
1/4 drive ratchet
3/8 shallow socket
1/4 inch deep socket
14mm shallow socket
15mm shallow socket
14mm wrench
10mm wrench
medium pry bar
most importantly 1 paperclip (do not forget to remove from brush holder, after alternator reassembly)

 

[dmilkman589]

lost me on the paper clip thing. but pretty much what im asking is what i am explaining, can this be fixed by just getting a new diode trio, brush holder, and voltage regulator like supplied in the basic rebuild kit. or should i but the more advance one that comes with the rectifier and bearing. i dont think i will be able to press the bearings off. or are they not pressed on?

 

[Dr.Jay]

The paper clip is used to hold the brushes in the retracted position in the brush holder so you can re-assemble the alternator. Once you have the the alternator re- assembled, you pull the paper clip out, and the brushes spring against the contacts on the armature.

The basic kit should solve your problem. It takes more time to remove the alternator, than it does to install the basic rebuild kit (if you have experience).

 

[dmilkman589]

got the thing split in two. how on earth do i get the stator out!!!

 

[dmilkman589]

never mind. i spoke too soon, i got it out. now im going through doing an ohm test on everything. i cant figure out how to test the voltage regulator though

 

[Warthog]

never mind. i spoke too soon, i got it out. now im going through doing an ohm test on everything. i cant figure out how to test the voltage regulator though

YOu can't test it without the proper equipment. Just replace it.

Are you using the TM 9-2320-289-34 tech manul to do your testing and rebuild?

 

[dmilkman589]

yes im attempting too. im going to nappa in the moring to buy regulator and brush holder. im going to start with that and see how it works. with the diode is it suppose to be an equal reading on each pole that gives a finite number or is each ohm reading suppose to be different?

 

[dmilkman589]

put in fresh voltage regulator and bush holder with brushes, i got my voltage back! for the most part mastered the procedure. anyone have any questions just pm me and ask me.

 

[milkie62]

Grasshopper,I taught you well when you were just a tenderfoot.

 

[dmilkman589]

got in the m1009 today and drove it down the road. the front battery wasnt charging again!!! i shut all electronics off and got out and looked at stuff cause i was pissed. the i tapped on the alternator. walked around the truck a little bit more and then got back in then hmm. there is all my voltage back. what on earth could be going on?

 

[dmilkman589]

so its constant. when i rev the engine i loose voltage. and when its cold it makes it worse. what part of the alternator needs to be replaced!?