Charging Issue
 

Hello,

1989 3vze 5spd 4x4

A bit stumped, started driving my rebuild project today, and after 5 or 6 starts i noticed the battery seemed a bit weak. Tested with a meter and it was 11.6 Volts. I put the charger on for a few hours, battery now reads 12.3V. Started the truck, battery + to - reads 12.3V, alternator output ring to batter - 12.3V. The battery light and brake light are not illuminated, however do illuminate with key on, so the bulbs are good. I believe that alternator is not working, but why would the battery light not illuminate?

Side issue, may be related? Signal lights now buzz when turned on, same with hazards. Basically relay buzzes when hazard/signal selected. Tried to unplug rear harness to eliminate a ground issue, same effect. I am going home to see if I have a spare flasher relay, and to swap out the hazard switch as I know I have a spare of that. Will report back.

Any ideas?
Thanks,
Ian

I recently had a bad alternator on my '87 that did not illuminate the brake and battery light like the previous times when the alternator died (had the truck for 25 years). My radar detector even went whacky, buzzing and flashing as well. Something it had never done before with a bad alternator. After testing everything in sight I decided to pull the alternator and have it checked. Bad alternator! 12.3v while running is an indicator of a charging problem but I'm no expert.

I pulled the battery terminal off while running and the truck stumbled, stayed running but barley. I charged up the battery, so hopefully it will make the 15min drive home. New alternator may be in order.

Flasher Relay was faulty. Swapped it and the flashers/hazards work fine now. Bought a new alternator, will try that tomorrow.

Back in the old days before computer controlled engines you could get away pulling off a battery terminal with the engine running .

Now it is a good way to cause very expensive parts to be paperweights

You are having your alternator checked it might have just been a corroded plug

Wyoming9 is quite correct! Never, never, never pull the battery cables off a running engine!!!!! That old trick has not been valid for about thirty years now.

Uh, 1989 IS about 30 years ago.

But you are correct. ianjadkins dodged a bullet (we hope) when he pulled the battery cable. Let's hope for the best, and hope he learned the easy way (not the hard way) to not do that again.

Yeah In hindsight that was not a good move. Luckily everything is fine. Anyways found another alternator in my junk pile. Swapped and all seems to be good.