Solved!: Battery warning light intermittant

[fishgo]

My battery light is beginning to light. I just completed a 4,000 mile trip and the next day the warning light was on longer than normal during start up. As I drove off (higher RPMs), it went out. After a few stops (key off), the lap stays lit all the time. Alternator charging stops.

The next day, lamp would go off and system would charge as normal when first running the van, but after a few minutes would then be lit all the time and the alternator would not be charging.

This morning I did some sleuthing. Alternator belt is OK, plug into the alternator tight. I unplugged the blue wire per another post (key off), and with the key on the lamp stays lit. When I started the van the battery lamp stays lit. When I plug in the blue wire the lamp went off and the alternator charged. I haven't gone for a drive yet but am making the assumption that it will stop charging.

I have a solar panel charging the system as well, which throws off the volt meter charging levels I see. I can actually drive the van during the day off solar / battery power but will see different charging values if on solar versus alternator charging levels.

What order of diagnostics should I check? Belt is tight, so next might be what? The testing sequence in Bentley is a little vague.

Van = 1983 2.0 AC with a starter & house battery and solar.

[jlrftype7]

Possible voltage regulator failing, or your Altn. internals. More knowledgeable owners who have split charging systems can reply about the Warning light even being able to light up with the Blue Field/Exciter wire removed from the Altn. with the ignition key on.


This was my regulator , I replaced it before a long trip as a just in case part. They do wear out….
Months later the diodes or other part started to act up inside the alternator, and I had to change the whole alternator.
I have a dash mounted voltmeter to monitor charging, the new regulator improved charging from an average of 13.6/13.8v to 14.2v upon replacement. Those brushes were on their last legs and could have failed at any time on us while driving.

_________________
'68 Westy- my first VW and vehicle/Bus- long gone.- sold it to a traveling Swiss couple....
'67 Type 3 Fastback, my 2nd car- gone
'69 Semi-Auto Stick Shift Beetle-gone
2017 MINI Coopers, our current DDs
‘84 Tin Top - Hilga....Auto

[fishgo]

Can just the regulator be replaced, or is a rebuilt alternator needed?

[VicVan]

It's easliy replaced, however you should diagnose if that's indeed the culprit. It's a 30 second check, all you need is a voltmeter.
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'90 Little Blue Truck, 2WD auto, FAS GenV 2.0 NA (AVH)

[Ronzo_volvo_guy]

fishgo;

Your symptoms are those of worn Alt brushes...as they wear and get shorter, they no longer make adequate pressure on the slip rings and Alt Field current decreases, decreasing Alt output to the point of zero...elevated RPMs sometimes help for a while, but the first thing I would recommend is changing the VReg/Brush module (see jlr...'s pic, the Bosch module should be about $50) ...and this can certainly be changed without changing the entire Alt which should also answer your question.

"unplugged the blue wire per another post (key off), and with the key on the lamp stays lit. " Battery Warning light indicates when Chg Sys has no output, so before engine is started and Alt is turning, of course you expect/want it to be ON... "I started the van the battery lamp stays lit.[no surprise! Chg Sys is not active because initial Alt Field input current is applied by way of that connector so that Alt can start putting out. ] When I plug in the blue wire the lamp went off and the alternator charged." ...OK, but I agree with Vic, it's better to connect a VMeter to the system after module replacement (or even now, after Indicator goes OFF at elevated RPMs), to see that Alt output is pulling up system voltage.

Cheers

[fishgo]

Maybe this might be the problem?

Can anyone identify this brand? I just ordered a Bosch model and hope it fits in the meantime.

[DanHoug]

Transpo is a budget priced Chinesium product, adequate for the price but carry a spare.

you prolly already ordered a regulator but this would be the time to install a VARIABLE voltage regulator and set your own charging voltage. requires owning a voltmeter to adjust it but you can really optimize your system

you want the "Internal Adjustabe Regulator" for 28mm slip rings from this page
https://www.prancingmoose.com/AdjustableVoltage.html
_________________
-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[Ronzo_volvo_guy]

fishgo; Yes, the non-protruding brush definitely has an issue...it hardly makes it out of its pocket...how is it supposed to make good, springloaded contact with its slipring, for the purpose of carrying current?...I'd pull both brushes and their springs out to compare and see what the issue is with the short brush/sping...collapsed maybe...maybe it was overheated due to current-flow and lost its temper...as "china's best" product...who knows!...those guys could f up a junkyard! [I hope I don't get a talking to from the admins again for that, but it's true and I absolutely stand behind it, having been burned too many times!]

Dan; (...but not adequate for the job once again!) I know Dave Burton from the Volvo world...he supplies electrical harnesses and other quality solutions, so I don't mean to badmouth him, but fact is that a variable VReg is rarely a proper engineering solution...but a band-aid to address some other root issue which has not been located and addressed properly...and this is typically a Voltage Drop on a series resistance in the current path. People install an adjustable VReg, and turn it up so that it still charges the Batt even though there is some drop in-line which should really be located and eliminated (because since they are typically due to a corroded or loose connection, they rarely get less over time...).

My general advice is to wire Starting, Charging and all other high current paths (like the main power buss to fuse panel, but also often overlooked chassis connections) with nice fat conductors (sized for the highest currents they will see, plus some margin), proper terminations, and everything long-term protected against corrosion with ACZP, and you'll find you won't need any tricks like accommodating a V Drop somewhere.

Ref: http://www.sw-em.com/anti_corrosive_paste.htm

Cheers

[DanHoug]

Ronzo- one of those issues the band aid of a variable regulator addresses is the poor quality control of available fixed voltage regulators... their voltage set point can be trimmed to anything from 13.6 to 14.8 or just a generic decision by the manufacturer.

back in the day with mechanical voltage regulators, you'd bend the fixed tang and shoot for 13.6 but it was under your control... a variable regulator if you will! with battery chemistry somewhat different now, aka 'low maintenance' i have good luck with running them higher, as high as 14.5.

this is all for 'dumb' alternators... it's crazy to watch the voltage on a modern 'smart alternator' car with voltage controlled by the ECU map. it's all over the place from 12.8 to almost 15 with little observable rhyme or reason, i suppose for economy and emissions optimization.
_________________
-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[fishgo]

Update: New voltage regulator from FLAPS (Meyer brand?? knock-off but works) brings charging back to normal operation. I'll order a spare and keep it in my on-board storage spares kit. Thanks all for the suggestions.

[a2wolfsburggli]