Alt warning light on - '78 Westy

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honeybus
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Alt warning light on - '78 Westy

Post by honeybus » Sun Nov 01, 2015 8:04 am

Normal '78 Westy.

Normally a tough bus to start (I believe a bad battery), so I let the bus drift backwards, to catch it in reverse.

The bus started with no problem, but I noticed the alternator warning light stayed ON. So I drove it forward the 50 feet or so, right into the garage, where it still sits.

There is no charge going to the battery, but the regulator shows reasonable ohm rating between the D+, D- and DF prong. It is a solid state regulator, relatively new.

Question: Is it likely that I have damaged the alternator (alternator diode(s)) in catching the bus in reverse?

I have an extra alternator in the garage which I will swap out soon, and I am just asking for opinions on my question.

Barry Burneskis
Aldie Virginia
Thank you for all the fish . . .

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Amskeptic
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Re: Alt warning light on - '78 Westy

Post by Amskeptic » Sun Nov 01, 2015 1:00 pm

honeybus wrote:Normal '78 Westy.

Normally a tough bus to start (I believe a bad battery), so I let the bus drift backwards, to catch it in reverse.

The bus started with no problem, but I noticed the alternator warning light stayed ON. So I drove it forward the 50 feet or so, right into the garage, where it still sits.

There is no charge going to the battery, but the regulator shows reasonable ohm rating between the D+, D- and DF prong. It is a solid state regulator, relatively new.

Question: Is it likely that I have damaged the alternator (alternator diode(s)) in catching the bus in reverse?

I have an extra alternator in the garage which I will swap out soon, and I am just asking for opinions on my question.

Barry Burneskis
Aldie Virginia
Not likely that you caused any damage to the alternator or diodes.

Here's what I think happened, and you MUST follow up here:

I think you unexpectedly jerked the engine jumpstarting in reverse and merely pulled the blue wire off the regulator plug harness. Go make sure the blue wire is intact to the harness leading up to the idiot light. There should be a rectangular connector adjacent to the regulator (not the black one if you have a black one) the blue one, which you must have. It may appear greenish if it is old.
Colin
That's what I think.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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honeybus
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Re: Alt warning light on - '78 Westy

Post by honeybus » Mon Nov 02, 2015 3:20 pm

Amskeptic wrote:
honeybus wrote:Normal '78 Westy.

Question: Is it likely that I have damaged the alternator (alternator diode(s)) in catching the bus in reverse?

I have an extra alternator in the garage which I will swap out soon, and I am just asking for opinions on my question.

Barry Burneskis
Aldie Virginia
Not likely that you caused any damage to the alternator or diodes.

Here's what I think happened, and you MUST follow up here:

I think you unexpectedly jerked the engine jumpstarting in reverse and merely pulled the blue wire off the regulator plug harness.

Go make sure the blue wire is intact to the harness leading up to the idiot light.

There should be a rectangular connector adjacent to the regulator (not the black one if you have a black one) the blue one, which you must have. It may appear greenish if it is old.

Colin
That's what I think.
Colin
Coln, the BLUE wire IS connected. When I turn the ignition on, the alternator warning light comes on. As expected.

So, when I pull the blue wire OUT of the connector (I disconnect the blue wire from the regulator), the alternator warning light goes OUT.

I believe I would NOT GET the alternator warning light ON at all, if the blue wire was not connected to the regulator.

I am in process of replacing the alternator/ harness to regulator / B+ wire to starter post.

I believe in the tooth fairy. Also . . .

I believe that the blue wire, getting power from the alternator warning light at the front instrument cluster, is using the regulator (and the follow-on alternator) as a GROUND.

This gets the needed power to the alternator to 'excite' the alternator, once the engine starts turning the alternator.

Then, the alternator pushes out power to B+ (the single fat red wire coming out of the alternator, to the starter post) and to the regulator. The power to the regulator does things, but it also feeds power BACK to the blue wire. continues back to the instrument cluster, to the pigtail of the alternator warning light.

Now, the alternator warning light has power coming in to BOTH leads, and there is no ground, only power, so the alternator warning light shuts off. And stays off as long the alternator / regulator connection generates power.

I didn't appreciate this scenario a couple of days ago.

Now, I believe I am NOT getting power out of my B+ wire (wired to starter post / starter post wired to battery) because, with the engine running . the battery charge never jumped above 11 volts (from a 12 volt starting charge),

Everything is taken apart now. So if the alternator / harness / B+ wire replacement fails, then I will come back (from lurking)

Barry
Thank you for all the fish . . .

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Amskeptic
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Re: Alt warning light on - '78 Westy

Post by Amskeptic » Mon Nov 02, 2015 7:34 pm

honeybus wrote: BLUE wire IS connected. When I turn the ignition on, the alternator warning light comes on. As expected.

I believe that the blue wire, getting power from the alternator warning light at the front instrument cluster, is using the regulator (and the follow-on alternator) as a GROUND.

I believe I am NOT getting power out of my B+ wire
Barry
I believe you are correct. Good luck finding out why your alternator/regulator decided to die.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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honeybus
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Re: Alt warning light on - '78 Westy

Post by honeybus » Sat Nov 07, 2015 10:00 am

I spent some quality time with my 32 year old son, replacing the alternator / harness wiring on my '78 Westy.

He was amazed to think that one person could replace the alternator (in situ) by themselves. but yes, two sets of hands are mostly better than one set of hands.

We stopped after the alternator was replaced. We did not hook up most of the engine tin, exhaust, B+ wire, etc. I know when I have lost his excitement to help his old man.

Knowing that he and my daughter are coming to the house today, Saturday, Monday I put everything back together. I turned the key and ZERO! My small battery was too weak to rotate the engine more than once, each ignition attempt.

Yesterday, Friday, I swapped my spare battery (driver side) with my smaller Interstate passenger side battery.

Bummer! The Westy starts right up, and the oil light goes out, but not the alternator warning light. I shut it down, and try two more times. Each time, the Westy starts immediately, and the oil light goes out, but not the alternator warning light, Darn. Darn. Darn.

So I sit behind the wheel, trying to get some spirit back in this old body, and think "oh well, another long night searching the forums"

Then I think, well, this problem (glowing alternator warning light always on) began as I was parked in my driveway, pointed up grade, and my small battery would not handle the challenge to start the Westy (lots of volts; no CCAs), I let the Westy coast backwards, and caught the Westy in reverse. Alternator light!!!

So, I figured, since the Westy will start and run (alternator warning light on), I would just REVERSE the procedure that 'caused' the issue. Right, go back outside the garage, point the Westy DOWN GRADE and coast, catch the engine in 2nd, and that would solve . . . (living the dream!)

As I sat hunched over in the driver seat, I heard myself say, to myself (I think we do that a lot, we bus drivers?) 'Why don't you turn on the lights?'

I heard that a couple of times.

Stupid.

So, in my darkened garage, I turned on the headlights (key on of course), OK, so what. Then my front fog lights. OK, I turn the ignition off. Darn alternator warning light.

I turned my (extra) backup lights on, and my emergency flashers. Everything worked.

So I started the Westy, started turning on my headlights, flashers and I noticed how dark it was in the cockpit.

Wait!! The alternator warning light is OUT!!. Shut 'er down, lights off and start the Westy another 3 times. Each time, the alternator warning light goes OUT, even before my oil light goes OUT. On the third time, both the oil and alternator warning light go OUT immediately after the engine starts.

Perfect!! All is well in fantasy land again.

Two more issues were revealed. (1) I seem to be getting OIL into my charcoal canister. Probably not so designed, and only 6,000 miles since a COMPLETE resurrection from an engine fire. (2) The bracket that attaches the bottom of the alternator to the cooling - fan shroud was almost non-attached. It seems that the two bolts had stripped out of the cooling - fab shroud, and the bracket was hanging in there by being wedged by the alternator. I put two longer bolts in, with the intention of going into the cooling - fan shroud (take the fan off) with two backing nuts on the, hopefully, protruding two bolts.

That's all.

(PS I am hoping to convince the wife that I should get an additional plaything. Another 'special' car. Saw it advertised in new Hampshire CRAIGSLIST. just a $200 air ride from Northern Virginia DC National airport. Probably need to have it delivered the 500 miles to home.)

Barry Burneskis sends (Aldie Virginia)
Thank you for all the fish . . .

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Amskeptic
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Re: Alt warning light on - '78 Westy

Post by Amskeptic » Mon Nov 09, 2015 8:02 am

honeybus wrote: (PS I am hoping to convince the wife that I should get an additional plaything)
Your indefatigable spirit . . .
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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