Volt light not coming on/10.9 - 11.2 volts?

[6=8]

I've had this problem happen 2 times in a 3 month period, and I am hoping someone has some insight...

Something is apparently on the way out, but for some reason the "Batt" light is not detecting it (I have checked... it does light up during key on/engine off and durning starting.)

Both times, I am driving around town, and notice the turn signal flasher is slower than normal. No adverse engine behavior, but I notice things like that! Anyway, I cycle the ol ScanMaster to read the battery volts, and it is way low. 10.9 to 11.2! The battery light is NOT lit when this happens, either. Since the ScanMaster and the flasher both indicate the volts are falling off, this seems to confirm I have a real problem (But without blown fuses, it seems like whatever is wrong it is not a short.)

Now, the problem does "Go away" if I continue to drive. This last time the volts rose to 12.8, and once the battery was recharged, returned to a normal 13.7v.

This problem is intermittant, and is a rare event. When this happened last, I was running with the parking lights on (Dusk), the other time I had the headlights on (Night) and noticed they were dim as well.

Anyone have a thought or two? Alternator or voltage regulator dying? Both? Loose/bad connection at the 1 wire connector? What would cause this problem and NOT light up the battery lamp?

The longest time I have experienced this is 5 minutes, then it recovers.

Please let me know if you have an idea!

 

[salvageV6]

I'd start with checking connections.

Battery + and ground cables, starter feed and output wires at the starter and the ground cable on the turbo mounting bracket front of the motor.

Then I would make sure the connection was good and secure between the alternator and the battery and do a resistance check on that wire while doing a wiggle test for intermittant connections.

 

[TurboBob]

There was a thread on fixing the alternator feed last year.

John Spina / Caspers has a kit that will fix it as well if the feedwire is the problem (sounds like it to me).

Bob

 

[JDSfastGN]

It only happened to me when it was cold outside, once it warmed up the bulb made a good connection, i took my dash off and messed with the connector to make sure it would always make a connection, no problems since. I think when it is cold the metal and bulb might not be making a good connection but once it warms it expands and makes a good connection this is only my guess, but I had the same problem. On cold mornings if I got on it with it like that it would fall on its face due to no voltage at the fuel pump.

 

[6=8]

Feed Wire and Battery connection check

Thanks guys for the responses...

I have verified the connections today before I left for work (Except for the starter... I'll do that tonight when I have time to jack it up but I did tug on it). I heard a rattling noise from the alt area, but figured the idler pulley/spring was making the sound.

I started the car, popped the hood, and did the following while it was running:

Wiggling the "Sense Wire" while viewing the battery volts did not indicate a problem.

Checked all cables giving each a "Tug" test... and also moved them around... No problems.

After about 5 minutes of idling, the alternator was hot to the touch. I observed Battery volt readings ranging from 12.9 to 13.8.

As an experiment, I shut the car off, turned the key to run pos. but didn't start it. The battery light was ON as it should be.

I then started the car, and at the alt, unplugged the 1 wire connector (Sensor?) and pretty much simulated my problem. Volts immediately dropped to 11.2~10.9 volts, under hood and interior light got dim, battery light stayed OFF.

It was at this point that the idle smoothed out, rpms increased, the alt "whine" diminished and a rattling noise almost disappeared!

I am now under the impression that I may have more than 1 problem:

The alternator bearings are shot (Rattling/whining)
The internal Voltage Regulator is dying.

My next question is what does everyone think... With the Alternator being about 6 years old (GM replacement), and both Pos/Neg battery cables are only 4 years old, is it normal to replace the Alt every 6 years or so?

My next step will be to change the alt with a new one. Regardless of the electrical glitch, I now know there is a mechanical problem with this one and must be replaced.

Let me know what you think! Again, thanks for the help!

 

[whitehot84]

Ah ha! The old alternator is not alternating problem. I have had this same thing happen. Go ahead and change the alternator because when it decides to go completely you will be stuck somewhere at the most inoportune time imaginable. Autozone here has a direct replacement with a lifetime warranty. Good luck.

 

[gaveMEaGN]

Pull the instrument panel and check the printed board for corrosion and also the bulb holder. Had a similar problem and that is what it turned out to be. Sometimes it would charge and sometimes it wouldn't.

 

[boosted]

ive been havin the same prob with my charging...my voltage on the scan master is readin 10.9-12.5 and the light isnt comming on...i havent found out the reason the charging system is soo low....ive replaced the alt, batt, and starter....ive heard from a gm mechanic who worked on the trs new...he said theres some fuseable links on the wires goin to the starter and if they go bad..they'll allow electricity to go thru but not enough to charge the system and just enough to keep from trippin the light....so he told me to see if my wires are either brittle or soft like......i havent checked mine yet but might be a possiblity for u...

 

[6=8]

Thanks you guys!

Yes, I am replacing the Alt. The noise it is making is not normal.

So, I am in the process of locating one... I can't even find the nice chromey one Kirbans had a while back.... I'm not sure about AutoZone's products... I have not had luck with either the parts or service they offer. Just my luck or what?

gaveMEaGN: You have me thinking about the bulb deal again. I know the bulb works during startup or key on/engine off, however, my oil lamp has not lit up for a while... Maybe it's time to take a look in there.

When I got a good PSI gage last year, I tee'd it off so I could Alert the idiot (Me) with a light in case I'm like watching the road or something when my oil pressure goes low... Did all that, and the light doesn't work anymore (Not even during startup, so I HOPE the bulb is just bad.) I'll tear it apart this weekend and verify both...

I still find it hard to believe it was designed so when the monitor bulb burns out, it takes the charging circuit with it? Thats like wiring the fuel pump to shut off when the gage fails!

To be honest, I didn't pay much attention to those posts about the bulb since it works when I start the car up, but it could be cause now that I think about it.

Again, thanks for all the help everyone!

 

[6=8]

Hi boosted!

Well, my plan is to first verify the bulb and then replace the alt.

I replaced the starter last year (Precaution) and checked all the wires down there... They seemed ok visually, but you bet your ... that I will be replacing those if my plan fails!

Thanks

 

[whitehot84]

The alt light on the dash is in the charging circuit for a reason. If the light comes on when you start the car or turn the key on then the charging circuit is OK. I had to pull mine once and clean the prongs. They are, after all, 15 years old. If the alternator is making all that noise though I would think it has some problems.

 

[87 Pete]

Originally posted by gaveMEaGN
Pull the instrument panel and check the printed board for corrosion and also the bulb holder. Had a similar problem and that is what it turned out to be. Sometimes it would charge and sometimes it wouldn't.

I had this problem (no charging, no volts light) after taking my T out of storage. Removing the cluster is a bit of a PITA, but I did this and cleaned up the copper contacts on the back of the cluster, and the ip. connector on the firewall. Just use some light sandpaper, like 320.

I also slightly bent out the contact on the ip. connector, I forget which one it was, but you can find it by following the copper trace from the VOLTS idiot light.

After I did this, my VOLTS light always works at key-on, and I've had no charging problems over the past 10,000 miles.

Pete

 

[salvageV6]

Look up Auto Electric repair shops in your area and have the GM one rebuilt with new bearings and they should easily be able to do a load test on it.

Sounds like all you need is new bearings in MHO.

Mine were so bad one winter they would actually try and stall the car when they squealed and yes the volts dropped too.

CS144 GM made alternators are very nice, I'd keep yours.

I had to use my car daily so I bought a new PROSTART made in the USA model. New not a rebuilt. It works great.

I did get the bearings for mine and will rebuild it when I get some time.

Just my .02.

 

[GNVenom]

You need this item:

http://www.casperselectronics.com/c...cgi?search_request_button=yes&keywords=102032

This will absolutely remove the "weak lamp connection" syndrome that the GN's have been plagued with. If the flex board doesn't make an adequate connection to the ALT lamp, the regulator won't function properly - hence, a depleted electrical system. I've seen the flex boards actually wear out, where the contact was worn right through the copper layer connecting the lamp socket. Don't chance it, add the harness and then don't worry about it...the charging system will always be at its peak.
-John Spina
http://www.casperselectronics.com