Saturday was a snowy, cold, very windy day and the charging system had a fit!

On a ride I noticed it didn't get too warm inside which is unusual. Noticed the heater fan seemed slow (on hi).
Battery gage was flat lined! WHOA, better get home! Made the turn, hit a bump and the gage went all the way to the top. After a second it died again. Then normal, then died.

Sunday, went and started it and it was showing a really low charge rate on the gage. Figured some snow may have gotten into the alternator and let it run. Went back out to check and the gage was flat, and battery dead.

Yesterday went out and wiggled wires (tight), Tapped the alternater with a wrench and proceeded to charge the battery.

Started it up andd the gage looked slightly above normal for charging.
Figured, "WTF?". Let run awhile, still good, went for a ride.
All seemed fine until I turned the lights on. Gage dropped a bit, lights on radio, heater controls, overhead console all went dim but not out. And the fan slowed again,,, considerably.

What the heck is going on?
Doesn't seem like the alternater is toast. If it is it's the first I remember acting this way.
Regulator?
Wiring?

I'm stumped as to where to begin and it's too danged cold to be wasting time hunting.

Any ideas where to begin?

PS; '99 expy EB 160K

 

I would start by checking that the wires going to the two main fuses on the firewall and the battery cables are tight. Then check the condition of the belt as well as the wear indicator marks on the belt tensioner. It could be a simple matter of the belt slipping.

 

I would take a voltage meter and check the battery voltage before starting it. Then start it and check again. It should be higher, if it is not I would say you have a bad alternator. As an alternative to do that if you have an Autozone or something similar nearby they can check it for you in the vehicle. The good news is that the alternator is very easy to change.

 

Thanks.
I am hoping it's the alternator (easy fix). But have my doubts.

VOM on battery-
Before and after reading are very close (everything off) to the same.
Unless I run it with the lights on for a spell, then it gets lower when shut down.
Telling me it's charging,,, just not very much(?) with load right now.
Saturday / Sunday it definately was not charging. (killed the battery)
Battery checks out as good.

Going into the shop tonight for repairs tomorrow. I'm just not smart enough to trouble shoot this and feel confident afterwards.

If it was a 60's model I'd be looking at the old mechanical voltage regulator with the contacts and coils. I don't think a new type can be "sometimes" or "almost good" and bounce in between like I'm seeing.
But, what do I know? (not much! )

I doubt the battery would live long enough for a trip to Autozone / PEP boys, round trip as it is.

 

So what battery voltage can you maintain with all loads on, start her up and turn on all lights, rear defroster, radio, blower or blowers if you have rear AC/HEAT you should be able to maintain 13.6 VDC at battery if not you have a alternator/ regulator issue assuming all connections are tight and clean.

The regulator is on the back of the alternator, it's solid state no more coils and relays.

 

Incase anyone is interested-

Yup,, was a kaput alternator.
(Whew,, wire gremlins scare the he^% out of me.)

 

Thanks for posting the the results.

 

Thankfully, these alternators seem to give a little warning before complete failure, at least in my case and the one posted.

I had a solid 10 hours for driving to do through Colorado after New Years. All was fine until I was having to make full throttle passes on the two lane highways. When it dropped a couple of gears the battery light would come on. It was daylight most of the way so minimal draw. Then I made a pass in the dark with the lights on and they went pretty dim until the trans upshifted again.

First I figured it was the belt slipping at higher rpm. I swapped that out but by this time the battery light was on full time. Turning the headlights on visibly drew down the volt gauge and raising rpm didn't help. Sure sign of an alternator not charging.

Just FYI, the voltmeter on our trucks isn't my favorite gauge for the electrical system. I would definately prefer an amp meter that clearly shows charging or discharging. If your volt meter drops while the engine is running and an rpm increase doesn't bring it back up to the 2/3 position, you have a charging issue. It was mentioned that the needle seemed to come up some. That is just the battery recovering from a load on its own. If the alternator is working the gauge will be all the way in its normal position ie 13.8-14.2V. If it is lower you are on the battery only.

Definately an easy change out, but not exactly a cheap part. Not what I wanted to spend $180 on right after Christmas

 

New England pricing?
First was $224
Wrong part for mine. (more than one listed)
Matching unit was $289 (ouch!) Higher amp rating (EB?).
If time permitted, internet purchased would of save a $100+.
But, had to have ASAP. (well, sorta )

All is done except the hitch (that will be Wends.)
Within 2 months;
alternator
Serpentine belt
Rim
Trans filter and fluid
Alignment (& kit)
Ball joints
Tierod ends
Ballance
4 shocks
light switch & bulbs
4 tires

I know, sounds like a lot. Some needed to be done (& knew it), some just to make me feel better.
Used vehicles with unknown histories always make me plan on extras.
All-in-all, I think I've done good. Basicly this has cost me about the equivelant of 9 new car payments total. I expect after a couple years my depreciation will be small compared to my last new vehicles. Plus, I can use it for what I got it for without dodging that first inevitable scratch or door ding.

I hear folks getting 300K+ on these. Hopefully I'll get 250K? I'd be a very happy boy with that.

 

Until it happens.