charging problem

[Premium72]

ive tried to figure this out on my own and with my stepfather. but no luck so far. new voltage regulator new battery. i had the altenator tested it was "good" i think it may be the problem. im only gettn 12.40 volts while the truck is running(testing at the +bat post and the alt bracket, -bat post, ground stap, block water pump..IE i have an open circut good ground) im not sure whats wrong. when i switch on my lights....i get a screaching belt noise..so i think the alt needs to be replaced. .im about to loose it. so before i have to buy another part this month i thought id run it by you guys. . help me out fellas. you always do . thanx. w.

[truckdude239]

if you are getting 12.40 volt with the truck running i'd check your grounds and cables. but i would look at an new alternator with built in reg the ext. regs aren't very stable heres the wirte up for it http://67-72chevytrucks.com/vboard/s...d.php?t=119379 go to the parts store and ask for a alternator off of a 83 chevy k-10 pick up 350 with internal reg mine ran 38 buxs with trade in be sure to tell them what year the truck you putting it on is to watch them freak out lol

[Longhorn Man]

Stupid Q... is the belt tight?

[Premium72]

yup belt is tite as can be....

[GMC AMI]

Originally Posted by Premium72

yup belt is tite as can be....

Too tight will wipe out the alt bearing after a while. That's what she said!

[Premium72]

ok in that tutorial he says.
"Now the wire bundle that runs to your old altenator from the voltage regulator consists of the Red, White, and Blue wires."i have red white blue and black. i have the the white and blue plugged in the alt. the red hooked to the larger post on the alt. and the black hooked to the smaller post. is this rite. i asumed this was a ground for the alt. am i wrong. help me out fellas this has been a nitemare for the last week. thanx. again.

[truckdude239]

Originally Posted by Premium72

ok in that tutorial he says.
"Now the wire bundle that runs to your old altenator from the voltage regulator consists of the Red, White, and Blue wires."i have red white blue and black. i have the the white and blue plugged in the alt. the red hooked to the larger post on the alt. and the black hooked to the smaller post. is this rite. i asumed this was a ground for the alt. am i wrong. help me out fellas this has been a nitemare for the last week. thanx. again.

red goes to battery post on alternator black goes to the ground screw on the back cuts brown and blue wires at voltage reg connect them together then jump wire a red wire off the battery post on the alt to termail number 2 and hook blue up to termail number 1 then the white wire? just cap it off no wire wire used i just used a piece or 12 gage auto wire for my jumper

[VetteVet]

Here is a great site to explain some problems. Hope it helps

http://www.madelectrical.com/electrical-tech.shtml

[Zoerb]

One trick I learned on an 86 Chevy was to disconnect the negative battery cable with the engine running (all power power acc. off including radio). If the engine stays running, the altenator is fine, if it dies, replace it with the Newer style with the internal regulator.

I also had an alterator that would test just fine at Schucks, but brought it to Napa and it was too low on amps, but would push the volts just fine.

just my $.02.....

[Longhorn Man]

Unplugging the battery only tells you if your alt is putting out a couple amps. Which is not enough to charge the battery, or even run headlights.
Doing this can also burn up the diodes in the alt.

[VetteVet]

Originally Posted by Longhorn Man

Unplugging the battery only tells you if your alt is putting out a couple amps. Which is not enough to charge the battery, or even run headlights.
Doing this can also burn up the diodes in the alt.

To add to this, on newer vehicles with computer controls it may cause voltage spikes from the alternator to destroy the sensors. The battery absorbs the surges from the alternator.
Here is another good site to check for rewiring an alternator conversion.

http://www.chevelles.com/techref/tecref14.html

[truckdude239]

heres a picture i borrowed from the write up

[RainFade]

http://www.lectriclimited.com/conversion_kits.htm

Check out their part # VAK6368SI

[Premium72]

well i had the altenator tested twice. came back good. i guess my cable and grounds arent as good i think...ill be playn with them today i guess...

[Longhorn Man]

Good call Vet, I tend to leave that part out only thinking of our old stuff... but you are absolutly right on that.

[Premium72]

whats the reading from the battery suppose to be at idel? im getn like 12.45 and as low as 12.0. this alright..when the truck is reving its putting out more so i assume when its driving it should keep a good charge for radio lights and what not..so im not stranded...this sound rite? thanx w

[Longhorn Man]

At idle, a good 13 - 13.5 is ideal, but a little less is to be expected in this old almost adequate set up. What does it go to once you are at speed?

[Premium72]

well last nite i did a deep cycle charge on the battery and put on a new belt. that seemed to work. at idel im gettn 12.75 with just a little gas its well in to 13volts. great. easy fix..thought i had serious problems...thanx agian. w.