Don't you just hate it when

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Pawned

Pawned

N.R.A. Lifetime Member - And damn proud of it
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Don't you just hate it when.

I had the dash cluster unhooked and out of the dash. I took it apart, did some light repairs, cleaned it and performed some preventative maintenance.

As soon as I hook up the battery, the fusible link is burning. Good that is what it is suppose to do. So I repair the damage and search to see where the problem is. The fusible link protected wire runs from the + battery directly to the + side of the ammeter. That is all. period.

There is absolutely no reason that the wiring should have burnt. There is no grounds, shorts, or any other reason this should have happened.

Don't you just hate it.
 
Are you saying the short is not there if the ammeter is unhooked? If so, has to be in the ammeter

Here's how you deal with this------------------

Before you replace the fuse link, hook a test lamp in it's place. Sometimes, a "high current" lamp makes things easier. I've used everything from "boughten" test lamps to turn signal/ dome lamps to headlamps!!!

The lamp will light because of the short, but will protect against more damage, and if you "wiggle test" and find the short, the lamp will flicker.
 
Might unhook both ammeter wires then see if it shorts and then hook up one at a time till the light lights up.

Del kinda said the same thing in a way.
 
I may be wrong and if I am these guys will straighten me out. I want to think that if the wires are reversed this could be a problem. My gray matter is kinda fuzzy any more so ?????????????????????????????????????????????????????????
 
67cudafb said:
I may be wrong and if I am these guys will straighten me out. I want to think that if the wires are reversed this could be a problem. My gray matter is kinda fuzzy any more so ?????????????????????????????????????????????????????????
Click to expand...

Wires reversed?

If you reverse battery hot and ground YES. The alternator diodes would cause this very symptom

If you reverse the ammeter connections, all that happens is the needle action is reversed, IE shows "charge" when it should be showing "discharge."
 
Actually, I was kind of loopy when I posted this. With out the ammeter hooked up power does not go anywhere. A DC ammeter (back in 71 ) must be placed in series to the circuit for it to give a reading. So I was way to quick to make a judgement.
The short is downstream from the black wire on the ammeter. If the wires were reversed on the ammeter, it would show everything reversed. I.e. show charging when the lights are on with the engine off. or show discharging when it is actually charging.
I will let you know when I find the gremlin.
 
OK, still, having a lamp in series will allow you to troubleshoot without burning more up.

First thing to do is unhook the alternator main wire. A short there will do this, or bad diodes.

Next pull fuses out of the panel.

Does it matter whether ignition, headlights, etc, are on?
 
I just put all new fuses (proper amperage fuses). I have a schematic, as lame as it is, so I should have no problem troubleshooting the problem. The only problem I really have is spending time in the garage when it is over 110 outside
 
I just spent the last few hours ringing out all the circuits connected to the dash. For the life of me, I have no idea why the fusible link burnt up. I reinstalled the dash and so far everything is working just fine. I put in the new wiper motor and it seems to be working OK.
While working around the carb, I found a long, thin lightweight metal wire spring sitting there unhooked. Any clues to where it goes. I can not find an answer in the Haynes or service manual
I think it is to hook to the choke to no allow it to fall closed
 
I finally got her somewhat in tune, so I took her out for a test drive. The wife got in and we took it around the block a couple times until she stopped dead. Nothing. Except the speedometer says we are traveling at 45 mph.
I thought it was the fusible link I put in earlier. I popped the hood and see the fuse is good, but there is a bunch of smoke. I see that the fairly long positive battery cable has fallen over against the exhaust manifold. So I grab the wire to pull it off and slightly burnt some fingers.
We walk home, get my car and go back to Natalie and jump start her. No Problem. Back into the garage.
Hopefully tomorrow she gets new brakes
 
So you still don't know yet? what caused it to fail the first time?
 
67Dart273 said:
So you still don't know yet? what caused it to fail the first time?
Click to expand...


Not a clue. I rang out every wire that was on the circuit. All the fuses were out of the fuse block, thankfully, so I did not have to ring out the entire car.

I got to tell you that anytime there is a problem, that fusible link is the first thing I look at.

She is at the shop getting new brakes and to see what else they think it needs that I can not do myself
I rinsed it off and this is what happened

https://www.facebook.com/photo.php?...722344.-2207520000.1375733778.&type=3&theater
 
photo.php
https://www.facebook.com/photo.php?...722344.-2207520000.1375733778.&type=3&theater
 
Take a look at your connections at the bulkhead. They are prone to melting. I replaced my bulkhead and wired the alternator wire directly to the starter relay. (Bypassed the ammeter gauge) Problem solved.
 
I took off all three bulk head connectors. Amazed me how much dirt was in there. Cleaned them up reattached them and still works

It is call FM
 
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