2000 Denali slowly losing power while driving

[Skweez]

I've been recently having starting issues with my 2000 Denali. At first I thought it was the starter so I replaced the starter. It continued to have starting problems sounding like it wasn't getting enough power. So I charged my optima battery overnight and it started fine. As we drive the gauge shows that we are losing power as we are driving. So I figure alternator replace that and the wires for starter and battery. Then I do a parasitic drain test and it shows that I have a draw of 0.04 when my multimeter is set to 10A. Any ideas I'm at the end of my rope with the electrical issues with this truck. Had major BCM for a while finally that was resolved now this.

[Jsdirt]

Go back over your grounds, take them off clean them up and put some dielectric grease on them and put them back on.

 

I also always rebuild my alternators and starters. It usually cost less and at least you know it fits properly. I had to have mine rebuilt, cost me $75 and a new one from Car Quest was $180.

That's the best way to ensure a failure free alternator or starter these days.

 

In 2007 I bought an alternator for our '86 Grand Marquis. Should've kept that OEM one instead of buying this reman in hindsight ... but I got over 7 years out of it (OEM lasted 21 years). I still had the receipt when it failed, so I brought it, and the battery back to AutoZone - got a new alt., and got a few prorated dollars back on the battery. Bought a new battery from Interstate, and headed home. Not 2 weeks later, battery is FLAT. Not even 1 volt! So I charge it back up, and notice the battery light is on in the dash - key off, engine off! Had a bad diode in the regulator.

 

Tried to return it, but the dummies at AutoZone couldn't get the concept that just because an alternator CHARGES, doesn't mean it's GOOD. Excessive AC ripple will cause all kinds of problems on new vehicles today. Mine was just flat shorted.

 

Bought a used regulator on eBay for $14, and it's been fine ever since (3 or so years now).