This can't be good.

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Jivermo
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This can't be good.

Post by Jivermo » Mon Oct 23, 2017 1:12 pm

Got back to Miami, after being up north for 5 months, and was eager to begin driving the bus around, in the cooler weather. It survived the hurricane OK, and my son had been starting it up on occasion to keep the lifters pumped. It cranked up, and I listened to the engine awhile...it sounds good. The next day, I started it again, and I noticed the alternator light was on. I checked the voltage at the battery, and an even 12 volts. Not good. Checked the battery connections and grounds and harness to the alternator. Looked good. I started it up again, and noticed that when I revved it a bit, the alternator light would go out for a short time, and then come back on. Then, all of a sudden the engine quit, and I smelled and saw an acrid electrical smoke coming from the open upper hatch in the cab. I went back with the extinguisher, but no flame, and disconnected the battery, also losing about a year of my life by breathing in some of that noxious smoke! Here is what I find: the large gauge wire from the starter solenoid to the alternator bolt is melted and fryed. I'll start tearing into the mess later this week, but the cause is puzzling to me. The alternator is a rebuilt one with maybe 300-400 miles on it. This is just plain crappy! Colin, you getting cold yet?

https://photos.app.goo.gl/7sJDCtb3UAjpMiRH3

https://photos.app.goo.gl/cNSgvQcjPDMhtW8i2

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zabo
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Re: This can't be good.

Post by zabo » Mon Oct 23, 2017 2:23 pm

looks like the alternator is shorting out out on something. Did you replace it or anything 5 months ago? or what did your son do!? :)
60 beetle
78 bus

Jivermo
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Re: This can't be good.

Post by Jivermo » Mon Oct 23, 2017 2:36 pm

No. Things were running well, and he only started it up, and ran it for 5-10minutes to keep the battery up, and circulate the oil. It’s a puzzle as to what caused this. The bolt on the alternator is not touching any metal, and has good clearance. It’s a real head scratcher at this point. Dang, I do not like electrical malfunctions.

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Re: This can't be good.

Post by Jivermo » Wed Oct 25, 2017 2:52 pm

I pulled the alternator today, a pleasant task...I had almost forgotten how much I enjoy doing that, right up there with new CV joints. Here is the alternator to solenoid heavy gauge wire, which had this three wire, non connected harness hanging off it...have no idea its purpose. I have laid it out in its pieces, melted insulation and all. As you see, the main wire is toasted. Fortunately, none of the nearby gas lines melted from the close proximity inferno. I have no clue what caused the short, other than the possibility that the wire abraded where it passed through the metal firewall, which had no gasket. I'm taking the alternator to the rebuilder to see if it is good. What is the story with the availibility of the 6 diodes for these things? What will our options be for 70 amp alternators, as they are like hen's teeth? Damn, I love these vehicles, but they are such a pain in the ass.

https://photos.app.goo.gl/DzsAEldLnVZhORAm2

bus71
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Re: This can't be good.

Post by bus71 » Wed Oct 25, 2017 5:49 pm

Don't Know if this is your issue but sometimes rebuilt alternators have a stud that can short out. I believe it's under the cover at the non-pully end. There are a lot of posts on the other site about this problem. Good luck!

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Re: This can't be good.

Post by Jivermo » Thu Oct 26, 2017 3:56 am

Thank you. That was the first place I looked, but the stud was clear of any contact. The stud is the alternator connection point for the wire that shorted out, B1 I believe.

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SlowLane
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Re: This can't be good.

Post by SlowLane » Thu Oct 26, 2017 3:28 pm

Jivermo wrote:
Wed Oct 25, 2017 2:52 pm
As you see, the main wire is toasted. .... I have no clue what caused the short, other than the possibility that the wire abraded where it passed through the metal firewall, which had no gasket.
I think that might be the cause right there. In the photo you provided, the wire is broken/melted through at about the right distance from the alternator to the firewall.
What is the story with the availibility of the 6 diodes for these things?
I bought some alternator parts from ASP Wholesale back when I was messing about with my Vanagon alternator. Ordered their "heavy duty" rectifier pack, but it turned out to be pretty light-weight compared to the one that was in my rebuilt alternator. I'm sure it would do if it was the only good one I had.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Amskeptic
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Re: This can't be good.

Post by Amskeptic » Sun Oct 29, 2017 8:20 am

Jivermo wrote:
Wed Oct 25, 2017 2:52 pm
Damn, I love these vehicles, but they are such a pain in the ass.
Hey Jivermo,
You should hear what they say about US . . .

That failure is not the vehicle's fault, and the odd wiring/ends is not factory-issue. Did you say that you did not have a rubber grommet between the firewall and the alternator B+ output wire?

Yes, I am getting cold here in the 48* Pensacola morning.
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

Jivermo
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Re: This can't be good.

Post by Jivermo » Sun Oct 29, 2017 9:04 am

Wire looks to be 10 gauge. Is that the correct size required, alt to solenoid.
“My woid!” said Mortimer Snoid,
As he leaned into the 2 liter void.
The franistan’s fine,
The timings in line,
Must be that damn solenoid!

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Amskeptic
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Re: This can't be good.

Post by Amskeptic » Sun Oct 29, 2017 9:20 am

Jivermo wrote:
Sun Oct 29, 2017 9:04 am
Wire looks to be 10 gauge. Is that the correct size required, alt to solenoid.
“My woid!” said Mortimer Snoid,
As he leaned into the 2 liter void.
The franistan’s fine,
The timings in line,
Must be that damn solenoid!

Yes, 10 should be OK, but the weak link is usually found at the crimps to the end terminals. I solder them after crimping.

As is seemingly never taught,
The alternator is mostly fraught
With electricians abject,
Who just have to reject,
The very thing that renders it naught.

(or sumpin')
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

Jivermo
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Re: This can't be good.

Post by Jivermo » Mon Oct 30, 2017 4:09 pm

Hah! Took the alternator and had it tested. It’s OK. I asked the repair guy about the diodes, and he says they are very hard to source, as I have read before. He says that he checks the rectifier. All of this is Greek to me. Can anyone provide a description of how these work, and if a diode is faulty, what happens? I see that there are three positive, and three negative. I have the new wire prepared, and will finish the installation tomorrow, and see what occurs as I turn the key. I’m getting rather fast at pulling alternators, and replacing them...it is an art.

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Re: This can't be good.

Post by Jivermo » Tue Oct 31, 2017 2:13 pm

I buttoned up the alternator, with the new wiring. The 3 wire harness, from the plug in the alternator to the voltage regulator, was OK, and I checked the continuity out on all the contacts, cleaned and dielectric greased a bit, and hooked it up. The bus started right up. However, the charge light remains lit up front. Any hints on where to look next, tests, etc?
Oh, yes, I stuck in a spare voltage regulator to see if that might solve this, but the light remains on.

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Amskeptic
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Re: This can't be good.

Post by Amskeptic » Tue Nov 07, 2017 10:19 am

Jivermo wrote:
Tue Oct 31, 2017 2:13 pm
I buttoned up the alternator, with the new wiring. The 3 wire harness, from the plug in the alternator to the voltage regulator, was OK, and I checked the continuity out on all the contacts, cleaned and dielectric greased a bit, and hooked it up. The bus started right up. However, the charge light remains lit up front. Any hints on where to look next, tests, etc?
Oh, yes, I stuck in a spare voltage regulator to see if that might solve this, but the light remains on.
Oh dear,

This should not be happening.

a) Disconnect blue wire connector adjacent to the plug underneath the voltage regulator.
Turn on ignition. Alternator idiot light should be off.
Now, supply ground to the vehicle side of that connector. Alternator idiot light should go on.

This is to determine that you don't have any stupid cross bulb installation going on at dash,
(i.e. How Many People Have Plugged In CAT/EGR Light To Alternator Warning Light Socket?)

b) Continuity test the blue wire connector that leads to the VR/alternator, engine and ignition off.
You should have continuity to ground.
Now, switch meter to DC volts, thoroughly ground the meter's black wire,turn on engine, and check for a 12 volt reading at the blue wire connector with your meter's red lead thoroughly contacting (you may need to rev engine a bit).

Rrrrreport back.
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

Jivermo
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Re: This can't be good.

Post by Jivermo » Tue Nov 07, 2017 7:10 pm

Thank you. I will delve into this tomorrow.

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Re: This can't be good.

Post by Jivermo » Wed Nov 08, 2017 11:07 am

Reporting Back:


a) Disconnect blue wire connector adjacent to the plug underneath the voltage regulator.
Turn on ignition. Alternator idiot light should be off. :cherry: Light is off.
Now, supply ground to the vehicle side of that connector. Alternator idiot light should go on. :cherry: Light comes on.
b) Continuity test the blue wire connector that leads to the VR/alternator, engine and ignition off.
You should have continuity to ground. :cherry: Blue wire has continuity.
Now, switch meter to DC volts, thoroughly ground the meter's black wire,turn on engine, and check for a 12 volt reading at the blue wire connector with your meter's red lead thoroughly contacting (you may need to rev engine a bit). :cherry: Shows 11.65 Volts, running. Battery power solely.

Do you suppose that the alt is not charging, even though it tested good?

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