Smokin' hot ampmeter !

[Deluxe Delivery]

Ready to fire up my 16 year ground up on the 31 Delivery. All new everything. As soon as I touch the neg wire to the battery, the ampmeter goes to full discharge and after a few seconds gets hot and then smokes ! WHOA...Quick disconnect and double check all my wiring. Switched ampmeter wires, same result. Switched coil wires, red and black in case I interpreted the diagram wrong... same results. What have I got here guys???

[1931 flamingo]

Something's shorted.........do you have it fused??
Paul in CT

[Bill Cal.]

My guess would be there is a short at the ampmeter. One of ther terminals could be touching the gas tank. Pull the dash away from the tank, start it up and see if it still shorts.

[Patrick L.]

For the ammeter to register like that, the ammeter is receiving power to the input stud and is then going to ground somewhere beyond that.. Like Bill said, check those terminals[kinda common I guess] and then everything beyond there one at a time.. If its not easily found, an in-line fuse or circuit breaker will help keep the smoke down..

[Deluxe Delivery]

No inline fuse. I pulled the dash panel away from the tank. Still same results. I pulled the junction box and tightened the screws a bit, thought they might be touching the firewall...no difference. Bad ampmeter ???

[Deluxe Delivery]

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Did a quick change of ampmeter and still hot and total discharge. ??

[Bob C]

I would disconnect the wires at the cut out, that would eliminate some
potential problem areas. Also check the stop light switch.

[Patrick L.]

The meter seems to be OK with just one wire attached ? With the meter removed and wires attached what happens? Either the meter is grounding or its grounding beyond the meter.. two meters shouldn't be bad, but, stranger things have happened.. Have you pulled the wires from the junction box and tried them one at a time ? The distributor wire or brake lite switch,etc could be grounding..

[FL&WVMIKE]

DELUXE DELIVERY ..................
You have a dead short, somewhere. Nobody, here, can tell you where it is.
There is not that much wire on a Model "A". Just start at the battery and visually inspect everything. It is, probably, something very obvious.
Let us know what you find.
MIKE

[BILL WILLIAMSON]

Originally Posted by Deluxe Delivery

Ready to fire up my 16 year ground up on the 31 Delivery. All new everything. As soon as I touch the neg wire to the battery, the ampmeter goes to full discharge and after a few seconds gets hot and then smokes ! WHOA...Quick disconnect and double check all my wiring. Switched ampmeter wires, same result. Switched coil wires, red and black in case I interpreted the diagram wrong... same results. What have I got here guys???

I would take a quick look at horn wiring like maybe shorting inside horn cover and inspect hot wire going to stop light switch for shorting and maybe disconnect that wire from switch to eliminate possibility of switch shorting internally.

[Jim/GA]

You are going to burn stuff up going forward like this. Hook the ammeter back up.

Remove both wires from the cutout and make sure the one coming down from the terminal box can not touch anything. (It is hot.) Tap the battery ground wire to the battery while watching the ammeter. If it jumps, you have just ELIMINATED a problem in the entire lighting and horn half of the car's electrical system. Search through the wires up in the terminal box and instrument panel for the problem.

However, if the ammeter does not peg, then you need to look in the lighting and horn part of the car for the problem.

Previous posters have given you plenty of ideas on where to look there. The horn feed wire is a good one. Make sure your light switch is in the OFF position (6 o'clock).

As you disconnect things, just tap the ground to the battery post. If the needle pegs, you still have a short.

[Tom Endy]

If you installed a reproduction terminal box on the fire wall, this could be your problem. The two studs that stick out the front are actually screws with the heads inside two tunnels on the backside. It is possible when hooking wires to them for one of them to back out and touch the firewall. The ammeter wiring straddles these two posts.

A good practice before installtion on the firewall is to fill the tunnels with JB weld.

Tom Endy

[Marco Tahtaras]

Is there any chance you connected the wire from the terminal box to the cutout on the wrong end of the cutout? If it's on the same side as the generator post it will do as you described. On a positive note you will have polarized your generator!

[cayager]

you did put the positive side of the battery to ground right?.

[Deluxe Delivery]

Wow, thanks for all the suggestions, guys, I will answer each one. ( please excuse the delay, had to take the Mrs. out to dinner, I'm sure you understand).
Yes, positive side of the battery is grounded. The wire is on the correct side of the cutout. It is a repo terminal box and I did remove it, tighten the screws and try it without installing it back on the firewall. Removed Distributor wire. Removed horn and taped and seperated the wires. The best results came when I did as Jim/TX and BobC suggested and disconnected the lighting contact at the cutout ! No more pegging ! Next stop...stoplight switch. Thanks for all who answered. I'll keep you posted, it's not over yet !

[Deluxe Delivery]

I believe I found the culprit! ...wait for it..................THE STOPLIGHT SWITCH ! It had been sprayed with a cadmium/zinc-looking metal "plating" back in the 70's and packed away. Upon examination, the metal coating, which looks great, by the way, covered everything, including the fiber insulator that seperated the two contacts. Scraped it off, reinstalled, and all looks good, no pegging, just a little tweek of the needle ! Thanks again to all who posted, this is the barn at it's best. I have a slightly better level of confidence as a result of this methodical search.

[1931 flamingo]

Glad you found the problem. There's lots of help here, all someone has to do is ask.
Paul in CT