Topic: Ammeter blew up

[Sig 65]

On my 1965 Mustang I updated the gauge cluster to the five round gauges (original restored).  I carefully followed instructions and it seems like many have done this before me.  However when I started the car the ammeter blew up, literally.  I saw flash and smoke.  I quickly disconnected the battery and removed the gauge from the cluster.  It was fried, I can see wire inside the unit burned broken.  I have gone over the wiring 100 times and I am pretty sure it is correct. 

Anyone had similar experience?  (Thinking I should have it converted to voltmeter.)

Cheers,
Sig

[midlife]

On my 1965 Mustang I updated the gauge cluster to the five round gauges (original restored).  I carefully followed instructions and it seems like many have done this before me.  However when I started the car the ammeter blew up, literally.  I saw flash and smoke.  I quickly disconnected the battery and removed the gauge from the cluster.  It was fried, I can see wire inside the unit burned broken.  I have gone over the wiring 100 times and I am pretty sure it is correct. 

Anyone had similar experience?  (Thinking I should have it converted to voltmeter.)

Cheers,
Sig

You must be using the 66 gauge cluster, as the 65 version of the ammeter is inductive and is very hard to fry.  The ammeters with two posts used for 1966 must be carefully insulated from the casing (chassis ground), as there is no fuse protection.  Before hooking up the wires, measure resistance between each post and the casing: should be on the order of 100kohms or more. 

What you experienced happens to the best of us, including me.  That incident (back in 1999) started me on the Mustang electrical knowledge path that resulting in a business.  Who'd a thunk?

[Sig 65]

Yes it is probably 65 gauge cluster.  Unfortunately I can not measure anything since the meter is fried, right?

[midlife]

No, you can measure now.  If the post is inadvertently grounded, then the internal wires get fried.  You'll still have a grounding issue.  Best to check when you install the replacement ammeter and before you hook up the battery.