Ammeter in instrument cluster short-circuit

[Erica]

I removed the instrument cluster on my dart swinger, from 1972. When I put it all back the ammeterconnections on the back of the instrument cluster sparks. The only thing I've done differently is to use a 72ah battery instead of a 56ah (as the 56ah is completely dead).
The battery sparks to.
Does anyone have an idea of what's going on? Is the battery too powerful?

I'm very sure I've put the cables to the ammeter in the right place. One going from the fusebox and one coming from the ballast in the engine bay. However, just to be sure, does anyone care to share which one goes where on the backside of the instrument cluster?

I have tried to switch places of the cables without success. Can the ammeter be broken and therefore short-circuit?

This is my first classic car and I wasn't expecting this problem when all I wanted to do was to install a new speedometer cable....

 

[Dana67Dart]

Go to mymopar.com and download your cars Factory Service manual in it will be the wiring diagram. Use it to be sure you got everything put back correctly.

As for spark... If for instance the headlights were on and you put the battery cable back on it would spark. Might be nothing. Make sure everything thing is turned off, doors shut, ignition off etc then touch cable to battery if it Sparks there is an issue some where.

 

[Mattax]

I removed the instrument cluster on my dart swinger, from 1972. When I put it all back the ammeterconnections on the back of the instrument cluster sparks. The only thing I've done differently is to use a 72ah battery instead of a 56ah (as the 56ah is completely dead).
The battery sparks to.
Does anyone have an idea of what's going on? Is the battery too powerful?

I'm very sure I've put the cables to the ammeter in the right place. One going from the fusebox and one coming from the ballast in the engine bay. However, just to be sure, does anyone care to share which one goes where on the backside of the instrument cluster?

I have tried to switch places of the cables without success. Can the ammeter be broken and therefore short-circuit?

This is my first classic car and I wasn't expecting this problem when all I wanted to do was to install a new speedometer cable....

I agree with Dana. If it sparks, as you suspect, there is a connection to ground. It could be as simple as having the door open and the dome light on.

The studs on the back of the ammeter should have an insulating fiber washer - especially if the ammeter mounts in a metal housing. I can't say specific for '72 but someone else may know. Post a photo if you can.

One wire on the ammeter connects to the battery. Most years it is red insulated.
The second post on the ammeter should connect to the main splice - that's a welded splice wrapped in electrical tape. From there one wire goes to the fuse box, one to the headlight switch B1 terminal, another to the ignition, and a fourth connects to the alternator.

All those wires are hot when the battery is connected to them.
Disconnect the battery, hook up the electric, reconnect the battery. That way wrenches, screwdrivers, wedding bands, etc don't accidently ground the battery causing spoarks or worse.