HELP! System Not Charging

[Scottie-GNZ]

I know this is not the correct category to post this but I need to get some help quick and I know most of the V-8s are using the same system.

 

My alternator does not appear to be charging. It is the single wire GM unit used in the 87 GN. I have the original Z 10-guage white/red wire connected to the batt terminal and the single brown wire from the alternator used as a tickler gets its source from a wire off the ignition circuit. That wire is run through a bulb which lights up when the key is on and goes off when the engine is running. Thats my low-budget idiot light (how's that for an oxymoron!). Test light at the alternator indicates there is current.

 

I have already killed one Die Hard (sic!) which Sears reluctantly replaced. They indicated the alternator was not charging and I scoffed at them because the alternator was brand new replaced only days previously. Now the new battery has run down twice and my data logger indicates the battery voltage at 11.9-12.1.

 

How do you guys have your single-wire alternator hooked up? BTW, few days ago I ran into the dreaded GM starter heat-soak problem. After letting the engine cool down for 30 mins it would crank right up. I replaced the solenoid and wrapped it and the starter with some heat shield material. Went to fire it up and NADA, just like when I had the heat-soak. I jump-started the car and vroom. I do believe I had a heat-soak problem but I also think the battery was run down and made it worse.

 

Scottie

[Guest Anonymous]

Hey Scottie,

If I remember right the brown wire should have full battery voltage to energize the alternator. There should be full battery voltage at the brown wire. With the car running you should have at least 13.5 volts at the white/red 10 gauge wire coming out of the alternator. You should have the same voltage at the battery as the white/red wire. If you have a voltmeter start by checking voltage at the brown wire with the ignition on engine off. Thene check the voltage where the white/red wire connects to the alternator with the engine running. If no votage is present at the brown wire thats your problem. If voltage is 12.6 or lower at the white/red connection the alternator isn't charging. I ran my field /brown wire straight off the battery. I how ever experiance the same problem adressed in our bible, I mean the JTR manual, my alternator will not start charging intill I rev it to 2000 rpm then it charges fine at any rpm. That puzzels me because I wired the alternator the same way that G.M. did it. Scottie if you don't have a voltmeter try a differnt alkternator. I work in a shop & see alot of alternators (and other parts for that matter) that are junk straight out of the box. The cheaper the part the worse it gets. You get what you pay for. I recomend A.C. Delco remand units. They seem to work the best.

Good luck Glenn

[Guest Locutus]

I concur about alternators being junk out of the box, I replaced one on my mercury mystique, and 3 weeks later it is toast again, this time I had the dealer look at it thinking I may have screwed up, but it was in fact a faulty alternator. 168 dollars for a piece of crap. the worst part is how much trouble it is to replace some of these damn parts. New cars are not worth it anymore. I will stick to my Z, and use only name brand parts that I can verify quality from others.

[Guest Anonymous]

I had simialr problem. With "new" alternator battery still went dead. It turns out after 5 yes 5 alternators the strater was faulty. Every time I would start the car, Starter would send an ac spike thru the wiring and kill the voltage regulator. It was not long after that the alternator would fail. The guys at auto zone hate me but the stood behind there lifetime warrenty. finally ended up replacing the starter. No more killed alternators. Good luck. Mark