Wiring problem - Help needed!

Hello everyone,

I've been having an odd problem with my 65 TBird.

First, a little background.

A few months back, I went to fire up the Bird and POW! The ignition shorted and filled the car with smoke. The bakelite rear portion of
the ignition melted, and I burned a good 3 feet of the large yellow ignition wire. I replaced the IGN switch. Then replaced the burned
section of wire all the way from the IGN switch to the nearest junction...about 10" past the burned portion of wire.

Car started and ran fine. Or so it seemed. After taking it on short trips around the neighborhood, I noticed that when I turned the heater
fan on HIGH (at night, so lights were on, too), the engine died. Started it back up and drove straight home. While in the driveway, I
tried it again...lights on, turn the heater fan on...engine died. Tried to start it, and nothing. Dead battery.

Oddly enough, the "turn on the heater and it dies" syndrome happened when the car was in drive, foot on the brake. Didn't seem to happen
when in neutral or park. I assumed the higher RPMs--lack of load on the electrical system--were what was saving it from dying.

I thought, maybe the battery was bad—it was old—so I replaced it. Yanked the alternator as well, had it tested and replaced it as well.

Car ran fine for a few days. One thing I noticed was when I started it, the oil pressure, temperature, and gas gauges would swing way over
and peg them selves for a minute, then slowly come back to "normal" readings. Otherwise, it seemed to be running fine.

Drove it around for a good 30 minutes yesterday. Parked it. Went back to start it a few minutes later...dead again!

I did not replace the voltage regulator when I replaced the ALT. Should I have? I'm thinking that somehow I'm running off the battery,
and it's not being recharged. On the other hand, when I had that initial IGN wire burning fiasco, I didn't do much but replaced
obviously damaged wire and the IGN switch. Could there be other damage/shorts caused the initial IGN short problem?

Any help would be mucho appreciated.

 

It is possible that your regulator is toasted. Sounds like between the heater, lights and brake lights the load is too much for the battery to handle. Try using a clamp on ammeter on your positive battery cable to see if it is actually charging while turning on each device one at a time. The only things that can cause the switch and wire to fail are: A. direct short. Crawl under the dash and look for scorch marks and bits of stuck insulation especially where the harness is near moving things like the steering column and parking brake (things get chafed over time). B. Loose connection. This could be almost anywhere. The light switch, heater motor or switch, brake light switch, voltage regulator and alternator. A loose or dirty connection will introduce resistance into the circuit and can cause all your symptoms including lack of charge.

 

Thanks Hup! I'll follow your diagnostic this week!

 

on the gages...those use a thermal voltage regulator gizmo (under the dash somewhere), and that behavior is kind of normal.....if you are still concerned, you might try changing out the regulator gizmo and it might make them behave better.

 

Thanks Squirrel. I mentioned it because prior to my IGN burnup, the gauges weren't doing that. I'll check into that as well.

cheers

 

Bet there is still some shorted wires or some wire melted together. disconnect the ground wire to the battery and hook a test light between the disconnected cable and the battery. If the test light comes on with the key off then there are grounded wires. You can also turn the ign on and the light should come on ---You can start pulling fuses and diconnecting accessories till the light goes out to help locate the specific problem area. DO NOT TRY TO START THE MOTOR WITH THE TEST LIGHT HOOKED UP IN THIS FASHION

 

I have dash clock that runs continuously from (and over time, drains) the battery. Will this still work?

 

After reading your problem it seems you might need to check the circuit that feeds batt to the ignition switch since you melted the yellow ignition wire it is possible you might have melted the battery feed to the switch also, so you might want to trace that wire back to the battery. It also sounds like maybe you fried more of the ignition wires down stream from the junction block so maybe your voltage regulator is not getting ign feed and possible the ignition feed to the cluster. It sounds like the short is on one of the ignition wires. Trace all the yellow wires from the junction to see if any are rubbed through or touching a moving pedal or bracket. The other issue I have seen is the harness rubbing on the brake booster bracket or another metal contact when the engine is put in gear or torqued causing a die out as you mentioned the failure happens in gear and not as much in park or neutral. Something has to be shorted to do that kind of damage and there should be evidence of rub through on the yellow circuit you just need to follow all the leads to figure which one.

 

4tford,

I'll give a more thorough look. When I replaced the burned wire a couple months back, I htought I'd checked everything. But I'll recheck again.

Thanks for the reply!

 

Best advice I have about wiring is...if you can keep the smoke inside the wires you have less problems soon as the smoke gets out....well you know already.