Hello all....My Alternator decided to just quit charging the other nite....

I have already gone into the Fix it threads and Added an External Regulator....

I am getting 12v to the Alt, and thru the Reg.....I am not getting any Exciter happening out of the Alternator....What gives...?

I am going to have the New Alternator tested just to be sure it is good, but other than that I am at a loss.....

Any help is appreciated.....

Thanks, John.

 

I have the exact same problem and i checked my wire harness and under all the tape it was melted you might want to check there

 

Where in the Harness....?

I am going to do a Crank sensor test to make sure it is getting signal too, but from what I read in the Alt. Fix thread, by putting the External reg in the loop, the Crank sensor is mute anyhow accept for tach signal if you are running tach.....

Beating my head on the Floor....

 

CRANK SENSOR FAILURE ALSO EFFACTS YOUR AC. I AM IN THE SAME BOAT, BUT WIRED IN AN EXTERNAL REGULATOR TILL I FIND THE CULPRIT. I HAVE TRIED SENSORS, ECM, AND NEW ALTERNATOR, CHECKED AND REPLACED ALL FUSIBLE LINKS AND STILL NO LUCK.

 

Ok, so After Beating my head against the truck till I bled.....

I still don't have juice.....

I had the New Alternator tested....at 2 differnt Shops.....Original store I got it from Says New Alt is Bad.... Go Figure.....???

So I go take the thing to another Branch who has Alt in stock and Have it re-tested...
They say it checks out A-OK......????

I had them pull their New unit and Test it....It tested ok....So I brought it home....

My Factory harness is getting the Relay to Fire juice to the Alt on initial Key on to start...
Once I fire the truck up though, the Thing is Not lighting back up...?

I did a Ground Jump to the relay, and It gets Juice to the Alt again in the Field wire on one leg only....Should it be getting power on both...?

With the ground jump, I am still not getting any power/amperage out of the Alt.....?

With the External Regulator, same exact situation.....????

Can someone PLEASE tell me what Excites the ALT.....?????

Or What Am I missing...?

Does anyone know where to get the info needed to test the Crank sensor...?

Does the Alternator need a Minimum Voltage to Light off...? I am currently at about 11.9 volts on a Deep Cycle....???

I'll be letting the Battery trickle charge overnite....

Thanks, A bruised and frustrated Mechanic....

 

Pretty much all the wires from the alt to the ecm to the dash but mainly in the corner closest to the driver on the left side were it goes into the fire wall im almost done rebuilding the harness and see if that fixes it cuz im having the exact same problem your having i replaced everything and added everything and still no go so hopefully this is it

 

I had that problem when i took my truck to best buy to have a alarm/ electric start put in. Something they did screwed up my ac and charging... I took it back he in plugged everything plugged it back in and havent had a problem since?

 

If you have a multi meter with tach set it to 6cyl and check the three wires coming from the cps. You should get around 600 rpm at idle, if so if its not iradic then it might be okay. When I checked mine the rpm's were all over the place. If you have to replace the cps it has to be set at .050.

 

There are at least 7 fusible links on the 93 trucks. It would be my guess you did something that shorted out the system and blew one of the links.

At your battery on the positive side there are 2 large one black in color wires. Just behind the battery down on the fender well there should be five more you can check.

Dont feel bad if you find one bad I have blown 2 of them over the years..

 

So I had to walk away from the truck for a few days and get other Work done....

Yesterday afternoon, I went back in and Looked things over....

First thing I found was my driverside Door Wiring brittle and broken in the door jam

I rewired the whole mess.....That was an unplesant chore...

Then I went out under the hood and re-checked all my wiring for the Alternator and External Regulator.....Checked all the fusible links...

Everything checked out good.....??? I was still not getting the regulator to do its job right...

I went and Bought another regulator.....

So when I installed it this is the way I made sure it went.....

I ran power to the Alternator off the main Harness, as it checked out good and ok...
I ran a key on hot wire to the top post on the regulator....
I ran the two regulator wires to the Field wires on the Alternator...
I took off the original 2 field wires in the harness to the Alternator and taped them up out of harms way...
I built a ground wire and ran it from the ground on the Alternator, to the chassis on the regulator which is now bolted to the side of the fender close to the Air box

Fired the truck back up....

Bam...I now have Power and the Alternator is Charging as it should be.....

Thanks to everyone who gave input ......

John.