Printable Version of Topic

Click here to view this topic in its original format

914World.com _ 914World Garage _ Good news ...Bad news

Posted by: simonjb Nov 4 2018, 11:17 AM

So the good news is that I managed to get the new engine started today. She fired right up after a crank or two and ran great!! First time in 2 years...

Then, I noticed the alternator light was on -RED. Then I noticed a bunch of smoke from the engine bay. Turned her off and...The red wire from the starter to the alternator was red hot and burning...it burnt all the way to the alternator from the starter.......

The battery was also making strange noises....and was very warm

When I got the engine the harness was already connected. I connected the longer end to the starter. and also plugged it in to the relay board

Attached Image
Attached Image
Attached Image
Attached Image

Sounds like something wasn't connected right? Perhaps the red wire wasn't connected correctly to the alternator?

Posted by: Mike Bellis Nov 4 2018, 11:36 AM

That would be a dead short to cause the burned wire. Happened to me one time on my Jeep when a non-fused wire hit the chassis.

Verify the circuit pathway was/is correct and make sure the ring terminals to not touch grounded metal.

Posted by: mepstein Nov 4 2018, 11:39 AM

Glad it wasn't a whole lot worse.

Posted by: wndsrfr Nov 4 2018, 11:50 AM

QUOTE(mepstein @ Nov 4 2018, 09:39 AM) *

Glad it wasn't a whole lot worse.

As beautiful as your car is, I'd suggest that you take it as is over to Chris Foley to correct the wiring and to verify that the alternator and circuit board is properly functioning...

Posted by: dlee6204 Nov 4 2018, 01:06 PM

Was this a rebuilt alternator? Likely the stud terminal on the back of the alternator was too long and contacting the cover.

Posted by: sixnotfour Nov 4 2018, 01:07 PM

Clay wrote;
Hiya... Glad you are here. One thing to check on the electrical stuff... make sure the stud on the back of the alt for the positive battery wire doesn't hit the cover. It happens all the time with rebuilt alternators. Causes one hell of a short. I always put the wire on, and take a dremel and cut the remainder of the stud off. Then I make sure the boot is over the stud.

Posted by: simonjb Nov 4 2018, 01:14 PM

Yes, it was quite a scare and I was ready to pull the fire extinguisher but it went out itself...phew. I agree its a short. Everything looks good at the starter - so it must be at the alternator end. I'll have to remove the alternator and see if its visible. The wire itself was in excellent shape.

Posted by: simonjb Nov 4 2018, 01:18 PM

QUOTE(sixnotfour @ Nov 4 2018, 02:07 PM) *

Clay wrote;
Hiya... Glad you are here. One thing to check on the electrical stuff... make sure the stud on the back of the alt for the positive battery wire doesn't hit the cover. It happens all the time with rebuilt alternators. Causes one hell of a short. I always put the wire on, and take a dremel and cut the remainder of the stud off. Then I make sure the boot is over the stud.



Clay/Doug - yes it was. I suspect thats what it is. I'll pull the alternator and take a look. I ordered a new harness from Jeff.

Its a shame as the motor was running really well. Put the fuel in today and then fired her up. One small oil leak at the fitting on the Aux oil cooler which needed a tightening. All was great until the smoke started ! hissyfit.gif hissyfit.gif

Posted by: JOEPROPER Nov 4 2018, 02:57 PM

I've been trying to follow this build and lost track of where you were with it... Sorry to hear about the trouble, but excited to see it come together. I'm sure you'll get this fixed up and on the road soon. I look forward to seeing the progress here and hopefully seeing it in person one day!

Posted by: ClayPerrine Nov 4 2018, 08:50 PM

QUOTE(sixnotfour @ Nov 4 2018, 01:07 PM) *

Clay wrote;
Hiya... Glad you are here. One thing to check on the electrical stuff... make sure the stud on the back of the alt for the positive battery wire doesn't hit the cover. It happens all the time with rebuilt alternators. Causes one hell of a short. I always put the wire on, and take a dremel and cut the remainder of the stud off. Then I make sure the boot is over the stud.


That definitely sounds like me... but I am trying to remember where I wrote that. unsure.gif

It is the dead honest truth. I did the same thing about 30 years ago, when my car was still a /4. Roasted the engine harness. Learned from my mistake and never put one back without trimming the stud.


Posted by: simonjb Nov 5 2018, 05:53 PM

So I managed to get the alternator out..

As you can see, there was a short between the SIDE of the nut and the alternator cover plate. See straight edge of cover plate. The cover plate then also shorted against the engine itself.

What I can't figure out is why?

One option is that it looks like the nut was too wide? It doesn't look too long and it shorted to the side , not the top.

The second option is that perhaps the cover was put on incorrectly? You can see that the inside of the cover is mostly rounded - but then has a square side. Its the square side that shorted. But the cover has to point in the right direction for the rubber sleeve (for cooling) to attach to. So it seems it can only go on one way?

Not sure how to solve this…Ideas? This was all assembled when the engine was delivered.

and not sure if the alternator still works..
Attached Image
Attached Image
Attached Image
Attached Image
Attached Image
Attached Image

Posted by: mepstein Nov 5 2018, 05:56 PM

We take our starters and alternators to a local battery shop. They test for free and rebuild for $75-100 depending on what’s needed. Usually takes a day or 2. Ask around to find a local place that can do the same.

Posted by: simonjb Nov 5 2018, 06:03 PM

perhaps this is what happened ? Its the washer that shorted?

http://forums.pelicanparts.com/porsche-914-914-6-technical-forum/132735-warning-bosch-rebuilt-alternators.html

Posted by: Spoke Nov 5 2018, 07:17 PM

How does that 2nd stud compare with a stock 914 alternator?

Posted by: North Coast Jim Nov 5 2018, 08:26 PM

QUOTE(dlee6204 @ Nov 4 2018, 02:06 PM) *

Was this a rebuilt alternator? Likely the stud terminal on the back of the alternator was too long and contacting the cover.


Bingo !!!

Posted by: dlee6204 Nov 6 2018, 06:23 AM

I’ve also seen it before on a rebuilt unit where the black diode plate was mounted too high because of thick nuts used underneath it. I compared this to an original unit where thin nuts were used.

Posted by: dr914@autoatlanta.com Nov 6 2018, 09:52 AM

QUOTE(dlee6204 @ Nov 4 2018, 12:06 PM) *

Was this a rebuilt alternator? Likely the stud terminal on the back of the alternator was too long and contacting the cover.



I agree first place to look

Posted by: simonjb Nov 6 2018, 10:50 AM

So it looks like the post was not too high - rather the washer on the post B+ underneath the Nut was too wide. Thus it was hitting the side of the cover. The answer from another readers experience is to trim the edge of the washer. What a lot of work for a small thing that almost turned into disaster.

btw, what I saw, but failed to appreciate, is that when I had hooked up the battery the Alternator light on the dash stayed on. It stayed on after starting up the car also. This should have been an indication that something was wrong.....

Posted by: simonjb Nov 6 2018, 10:52 AM

Here is the solution...cut the edge off the washer
Attached Image

Posted by: sixnotfour Nov 6 2018, 02:42 PM

from samba
template for alternator gasket 021903637 / 021 903 637

Print out at 300dpi and you're good to go.


Attached thumbnail(s)
Attached Image

Posted by: simonjb Nov 6 2018, 03:50 PM

QUOTE(sixnotfour @ Nov 6 2018, 03:42 PM) *

from samba
template for alternator gasket 021903637 / 021 903 637

Print out at 300dpi and you're good to go.



Thanks

Posted by: ClayPerrine Nov 8 2018, 02:03 PM

That flat sided cover doesn't look quite right. I don't remember a flat side being on the alternator cover at all.

Let me look at my stash of alternator covers after work and get back to you.

Clay

Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)