(IT'S OK) What the heck did I do?

[Bob]

Ok, I know it was dumb but hear me out. I was at a flea market today and got an old set of dixie horns. Looks like original ones from 30 years ago. It was only 3 bucks. On a jump pack they worked about 80%. Oiled the motor and cleaned them up. Mounted in the car. I mounted the horns and compressor. Ran a wire from ground side to ground on battery. Hooked the other wire to my horn wire at the horn. Blew the horn on the steering wheel enough for it to run through the tones. Tried again and only got one tone. Here is the problem. Disconected all the dixie stuff, started car and now it won't charge. Switch off, 12.4 volts. Engine running 12.2 volts. What the heck did I do?

Bob

[moparguy01]

if its only getting 12.2 volts running your alternator is done.

Your car is probably just rebelling against having a dixie horn in it.

[Bob]

I knew that was coming
Anyway, you think it overloaded and burnt a diode?

[moparguy01]

well im glad I didn't disappoint you 

ya I think the addition of that horn might have been just enough to cause a problem.

[69bronzeT5]

Your car is probably just rebelling against having a dixie horn in it.

[Bob]

Ok, here is what I checked and replaced.

First, replaced alternator, voltage regulator and ballast. Fusable link fine.
Here is the funny thing. When the engine is off and the switch is off, the 4 ways and lights work fine. When I start the car the signals do not work and the headlights drain the heck out of the battery. Again, switch off 12.5 volts, start up 12.2.
When I disconect the positive battery cable and check between the positive terminal on the battery and the disconected cable I get 12.5 volts.
Could there be a short in the lighting system? Oh by the way the horn system is working fine. Dixie horns in the garbage.

Something else I did. I initialy had the horn wire hooked to the ground on the compressor and the hot to the battery. Could this have back fed through my ignition switch when I pushed the horn button? Nothing happened when I had it hooked this way and thats when I switched them around and it blew once.

[Nacho-RT74]

I'm reading and thinking and still dunno what the hell happened

[Bob]

You got me to Nacho . I also checked for reverse polarity in the battery and it is fine.

[Bob]

$10 Reward for the cause.

[Nacho-RT74]

Here is the diagram Bob... really sorry the size buit since I have 17" lcd monitor is hard try to fit diagrams on normal size.

I can make it MORE DETAILED including every wire and bulkhead cavity. Let me know if you need more than this.

Is the same to any year with 4 double ballast, elect ign and elect reg, just the reset button is different ( unexistant on earliers than 74 )

[Bob]

Thats perfect Nacho. I knew you had one. Now the trailing begins.
Thanks a million. If I find it you got $10

Bob

[Nacho-RT74]

I didn't had one, I made it

[alfanta]

checked your alternator gague in the dash?

[Bob]

I used a high speed digital voltmeter on the bat, alt, fields and regulator. Nothing yet. I told him to just sit there with his volt gage between his tail pipes.

[darkfiire5000]

Sounds like you might have a parasitice drain on your electrical system i would check for amperage at the battery with the negative cable off and see if you have any thing above .01 amps.

[Bob]

Well went out tonight and fired him up. Voltage while running, at the alternator, main wire, was 22.2 volts. What the heck?

[Nacho-RT74]

I got that once and was alt shorted, rotor as far I remember

[Bob]

I guess I better get another alternator. I think it may have been a coincident with the horns.

[Nacho-RT74]

short could it be anywhere on alternator... maybe in fact just broken brush insulators

[Bob]

At the batt it's still 12.3. Do think the voltage reg is fried to?

[Nacho-RT74]

maybe

but maybe you are still without output from alt.

check if you have 12 volts between brushes wires with key in run position ( not necesarilly engine running )

[Bob]

Will do.

[71_deputy]

check the bulkhead connections!!!!!!!!

[Bob]

I'll check that to. Thanks

[Todd Wilson]

check the bulkhead connections!!!!!!!!

Thats a good idea! On my 71 When I first had the car I kept bumping the inside of the bulkhead/fuse box with my left toe/foot and knocked it loose and the car continued to run fine it just wasnt charging.


I wouldnt be surprised if your new reman alternator is a POS also.  You can have them tested at a good parts store.There are 2 voltage regulators. The 15$ crap ones and the 40$ good ones. I just had to replace one in my 74 truck.  My 71 Charger has the dim headlights at the stop light problem and was really bad a few weeks ago when I had to drive in rain. Headlights,wipers and defrost running.  I have bought a new good regulator and gonna install it today and see if that fixes the problem. Last time I put a reg on my 71 had to have been about 1988 or 89 and I didnt have any money then so I know I bought the cheapo unit.

Its either the alt. or reg.   or you got something draining your juice. If you remove the + cable from the battery and get a small spark removing it or putting it back on you have something draining current. From there you can pull fuses and determine which circuit is the problem and go from there.  Bad diodes will back drain a battery in no time with the car sitting shut off.  Cheap part store reman alternators are famous for giving out as they use cheap repair parts and dummys remaning the units.   I usually try to take my starters and alts. to a real rebuild shop and spend the extra 50$ to have it done right.



Todd