1968 Charger Amp Meter/Electrical Issue

[dodj]

One correction, the "bar" is actually brass according to TLK.   I believe it.   

I never took one apart. I'm surprised it's brass. Pretty mediocre conductor. Guess they figured it was "good enough" for the small alternators of the time.

[aussiemark]

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

[chargerdon]

All Brass is not created equal.    Saw that "brass' is only 28% as good a conductor as copper.   Yet, the electrical plugs and receptacles all use brass..because copper is too soft to take the wear and tear.   Yet, Brass reinforced with certain materials rises to nearly as good as copper.   Im assuming TLK is correct that it is brass...  i dont know how to tell the difference.   

I do know this, using a digital multi-meter...the "removed" ammeter shows zero resistance across the two posts.   

Again, rather than condemning Chrysler for staying with an ammeter into the early 80's i applaud them.   I'm sure it costs a lot more to run the circuitry to enable the ammeter, rather than an "idiot" light that all cars have today.   Just wish they would have used 10 gauge and not put it thru the weak bulkhead connector. 

[70Barracuda]

Hello all,
Putting new gauges w a volt.

Bolting and taping the two amp wires is the fix?  No issues or concerns after that?

I'll look over the block, have had no issues.

[dodj]

Yup. Just bolt'em together and insulate.

[chargerdon]

Hello all,
Putting new gauges w a volt.

Bolting and taping the two amp wires is the fix?  No issues or concerns after that?

I'll look over the block, have had no issues.

Bolting the two ammeter wires together eliminates the ammeter...BUT..I STRONGLY disagree...that that is the fix.  It only eliminates the ammeter.     The real problem with the old B and E bodies is that the factory only used 12 gauge wiring from the alternator thru the weak bulkhead connector, to the ammeter and to the 5 connector block that feeds the entire car and then back thru the bulkhead connector to the starter relay.    So if all you do is eliminate the ammeter then you are only fixing about 10% of the problem.   The Mad Electric bypass of the ammeter also replaces the 12 gauge with 10 gauge wires and by passes the bulkhead connector by running the 10 gauge wires straight thru it.   THAT is the main problem.  Look it up on the net...12 gauge wire is only continuous rated at 20 amps !   

If you drain your battery and start your car, your alternator is going to be pushing 30-50 amps to recharge the battery over 12 gauge wires !!   Usually they will be able to hold that when new, (while getting HOT) but when then get old and you have some less than ideal connections heat can build !!   It will attack the weakest link which is the spade connections in the bulkhead connectors!!   They can melt and cause so much heat that the plastic can catch on fire, and then melt the insulation on the wires...and oh my  !!!

On my 66 Charger, i replaced the 12 gauge wire with 10 gauge wiring, and bypassed the bulkhead connector by running the wires to the ammeter and back thru another hole in the firewall.   To me ...this is the real fix and keeps the ammeter functional !!   

[70Barracuda]

Don,
Looking at the wiring diagram it looks like running a 10 wire from the alt stud to the bat post on the starter relay with a large fuse solves the problem if deleting the amp gauge?

[Chryco Psycho]

Hello all,
Putting new gauges w a volt.

Bolting and taping the two amp wires is the fix?  No issues or concerns after that?

I'll look over the block, have had no issues.

I prefer to bolt them together on one post of the ammeter that way they are held tight & not just floating around behind the dash , as long as both are on one post there is no risk .

[70Barracuda]

After peeling the tape back I found no insulation on the black wire for about 8 inches.  I soldered them together.  I will add a wire from the alt to the bat relay for extra protection.  Running a higher amp alt.