Ammeter on discharge

[Davidrad]

A few nights ago I was fixing my headlight switch and I had moved the fuse box out of the way. I get it fixed, I reconnect the battery to test, it works, (and here's where I do something stupid) I then proceed to push the fuse box back into place without disconnecting the battery and then pow it grounds on the dash frame and sparks fly. Every circuit in the fuse box and headlights still work. The ammeter is now all the way to the left on discharge whether the battery is connected or not. It's my understanding that if I blew the ammeter nothing else down stream would work so it's probably not that. Any idea what I could have done?

 

[RustyRatRod]

A few nights ago I was fixing my headlight switch and I had moved the fuse box out of the way. I get it fixed, I reconnect the battery to test, it works, (and here's where I do something stupid) I then proceed to push the fuse box back into place without disconnecting the battery and then pow it grounds on the dash frame and sparks fly. Every circuit in the fuse box and headlights still work. The ammeter is now all the way to the left on discharge whether the battery is connected or not. It's my understanding that if I blew the ammeter nothing else down stream would work so it's probably not that. Any idea what I could have done?

Possible fusible link.

 

[RedFish]

The amp gauge needle should rest in the center even when the gauge alone is on a workbench. Its makeup is a magnet in between to little limbs. I've seen a few that had a pretty good accumulation of metal dust collected on the magnet. I can only guess it comes from the mechanical speedometer in the same housing. That debris would draw the needle slightly to one side. Anyway... There could have been arcing/welding inside it. Current still passes through the shunt.

 

[67Dart273]

The ammeter is a ridiculously simple device. It is basically a strip of brass "shunt" which also generates a magnetic field with current. The "meter" is simply a metal/ magnetic "piece" suspended in needle ? bushings? and the magnetic field makes it move.

You likely "banged" it so hard when you shorted the fuse box that you "stuck" the needle. First thing I'd do is give the dash a smart "whack" with your hand and see if it comes loose. If not you'll have to pull the cluster

 

[Davidrad]

I took apart the dash this evening. I tried smacking it and all it did was move the needle around but not get it back to center. The short must have caused the metal to twist a bit because I found that the needle was now bent in wards . I bent it back and now it returns to center on its own like it should.

 

[RedFish]

The steel post that the needle is on was simply pressed in. It can fall out. Good luck with it.