'66 Imperial Ammeter

[Mick]

Happy 4th everyone,
Amp meter is dead. I recently had to pull the instrument panel because the odometer broke and the clock wasn't working. Got it back, hooked it all up, applied power and poof, blew a fusible link and no start. Took a look at the backside of the fuse box, and sure enough, had heavy corrosion on one wire, burn marks on another. Corrected fuse box issue, new fuse, new fusible link, and boom - fired right up...except now I noticed nothing on ammeter. Just dead. Pored over the FSM schematic (I'm no electrician), and posts here, but no joy.
Ideas or leads?

 

[Davea Lux]

Happy 4th everyone,
Amp meter is dead. I recently had to pull the instrument panel because the odometer broke and the clock wasn't working. Got it back, hooked it all up, applied power and poof, blew a fusible link and no start. Took a look at the backside of the fuse box, and sure enough, had heavy corrosion on one wire, burn marks on another. Corrected fuse box issue, new fuse, new fusible link, and boom - fired right up...except now I noticed nothing on ammeter. Just dead. Pored over the FSM schematic (I'm no electrician), and posts here, but no joy.
Ideas or leads?

Run a continuity test on the ammeter to see if it has burned out and gone open. It was pretty common for the needle on these units to get stuck as the units repeated heated and cooled from the load. If the needle is stuck it is in the first stage of failing and will sooner or later short out. In that case you should by pass the ammeter and install an under dash unit or try to find a NOS replacement. Would be a good idea to also do the partial ammeter by pass under the hood to reduce the load. There are several posts on this site about how to do that.

Dave

 

[Mick]

Thank you. I should clarify that the need isn't stuck, it just doesn't move one way or the other with power applied.

 

[Davea Lux]

Thank you. I should clarify that the need isn't stuck, it just doesn't move one way or the other with power applied.

Are you sure that power is getting to it?

Dave

 

[detmatt]

I might have some ‘66 instrument clusters for parts.

 

[Mick]

Are you sure that power is getting to it?

Dave

No, I am not.

 

[Mick]

I might have some ‘66 instrument clusters for parts.

Sir, you are a scholar. I may have to take you up on that.

 

[Davea Lux]

No, I am not.

In that case you have a fault in the wiring to the ammeter. See if you have power going into the firewall plug and power coming out of it. Power usually goes into the firewall plug from the heavy gauge red wire coming off the starter solenoid. You may have toasted the terminal inside the firewall plug when the fusible link blew.

Dave

 

[Mick]

I will do that. I can see where they come out and will check. Thank you.

 

[Mick]

Dave, Detmatt,
I have power on both sides of the terminal block.
Detmatt, price on an ammeter?
Again, thanks guys.

 

[detmatt]

Dave, Detmatt,
I have power on both sides of the terminal block.
Detmatt, price on an ammeter?
Again, thanks guys.

Tomorrow or Monday I’ll check my stash.

 

[detmatt]

I have 2 clusters that have all of their gauges in them and both alternator gauges tested good with a continuity test. In fact all of the gauges tested good Continuity. I’d love to sell these complete(best deal) but I would sell individual parts from them.

 

[Mick]

How much are you asking?
Also, if I am reading 12v from the inside bulkhead, does that mean the amp gauge is getting juice and is just defective, or do I need to check the gauge itself?
Can it be checked from the front w/o pulling dash?

 

[detmatt]

I would most certainly check the gauge itself and this must be done across the contact studs on the back. The individual gauges are $75 each or the entire clusters are $200 each without the hvac bezel or $225 with. The gauges are obviously very delicate so keep in mind that there’s risk in shipping them individually and I’d be reluctant about guaranteeing them as working if they have to be removed from the housing. That being said I would do my best packaging on them if you want to take the chance on just the alternator gauge alone.

 

[Mick]

Ok. I will do that last check. Throw in that gear selector cable?

 

[detmatt]

Ok. I will do that last check. Throw in that gear selector cable?

Yes.

 

[Mick]

Ok. I will pm you.

 

[Mick]

https://photos.app.goo.gl/hf6H2Kf1buxrz6zn8Before I consign my ammeter to the deep, I was wondering about this "accessory breaker" in line with the ammeter circuit inside the upper left bulkhead.
Should I be reading any voltage between it and the bulkhead if it got tripped?