Ammeter Replacement 66 coupe

[John F.]

lI have to replace the ammeter on my 66 coupe. Is there an easy way to do this, or am I looking at disconnecting everything, pulling the dash off in idea to get at it? I've don't it before, but it was many years ago, and I just don't remember. Thanks in advance for helping a senior citizen.

John Farren

[Michael F.]

Re: Ammeter Replacement 66 coupe

I did last year on my 67. Take out the drivers seat to give you more room. I did not take out anything else--except the old gage!

[Don H.]

Re: Ammeter Replacement 66 coupe

I agree with Michael, I just did my '65 ampmeter. (Be sure battery is disconnected.) AC does add more steps but it can be done without pulling the dash. Good luck, Don H.

[John F.]

Re: Ammeter Replacement 66 coupe

In looking at the back of the dash panel, it looks as though the meter is under a plate that would have to be removed. Am I correct or am I missing something obvious?

John

[Don H.]

Re: Ammeter Replacement 66 coupe

You have to pull that plate. The amp meter and fuel gauge are attached to it and they come out together. Good luck, Don H.

[John F.]

Re: Ammeter Replacement 66 coupe

Thanks to all!

John

[Frank D.]

Re: Ammeter Replacement 66 coupe

The plate has to come off and is secured with tiny, tiny, easy-to-lose screws. When installing just LIGHTLY snug those up...the threads only engage slight deformations of the gauge housing metal (there is no threaded hole) and can strip in a heartbeat...

[Donald H.]

Re: Ammeter Replacement 66 coupe

I expect you know for sure the gauge is bad, however my gauge was not working in my 67. It just stopped working. After a lot of research and testing it turned out to be the wiring connection at the firewall and not the gauge.

[Richard M.]

Re: Ammeter Replacement 66 coupe

I was wondering the same. Are you certain the Battery gauge is defective? You can do a test with it in place.

Remove the 2 terminal connector from the back of the gauge.

Get 2 AA batteries. One new and the other a old slightly used/discharged. e.g. 1.5V on the new, and 1.3V on the old.

Using some form of wiring method or jumpers, connect both batteries Negative to the pod/meter case. You can solder the wires right to the batteries or use a battery clip of some sort.

Connect the Positive of each battery to the 2 terminals of the meter.

If the meter is functional you will see it deflect slightly in one direction. If so, reverse the 2 Positive battery wires to the opposite gauge terminals. You should see the opposite deflection.

Note, do not use a 9V battery by connecting Pos and Neg to the meter terminals. A major peg of the meter could occur and do damage, or possibly spin the needle off of the shaft or spin the shaft. I once had a meter that someone tested that way. It caused the needle to spin on the shaft and reset the physical polarity. They replaced the needle, not realizing the shaft polarity changed. I was stumped.

Eventually I discovered this caused the meter to read backwards. I had to lift the needle and rotate the shaft 180* to 6 o'clock to recenter it, then remove the needle and carefully replace it on the shaft, centering the tip at 12 o'clock. The meter is self centering, but can be centered in 2 positions of the internal mechanism.

Rich

[John F.]

Re: Ammeter Replacement 66 coupe

Rich, I got the meter replaced as you all instructed. Good job for a contortionist! Unfortunately, when I reconnected everything, got the battery hooked back up, and cranked the engine, Nothing on the ammeter. Its a new front wiring harness from Lectric Limited, everything else seems to be working fine, all connections seem to be solid. I'm going to try the test you described with the AA batteries, and have just one question. When you say "negative to the Pod/meter case"I assume you are referring to the ammeter case and not the dash under panel itself. Is that correct?

John

[Richard M.]

Re: Ammeter Replacement 66 coupe

Rich, I got the meter replaced as you all instructed. Good job for a contortionist! Unfortunately, when I reconnected everything, got the battery hooked back up, and cranked the engine, Nothing on the ammeter. Its a new front wiring harness from Lectric Limited, everything else seems to be working fine, all connections seem to be solid. I'm going to try the test you described with the AA batteries, and have just one question. When you say "negative to the Pod/meter case"I assume you are referring to the ammeter case and not the dash under panel itself. Is that correct?

John

John, Yes the bare metal case where the meter mounts, or the small studs that attach it to the pod. With engine off if you turn on headlights you see no movement negative?

If so, I suspect your original meter was good. If so it's likely that you have a open circuit in one or both of the 2 feed wires to the meter. They are 16G Black and 16G Black/White. Blk/Wht goes to the Horn Relay 12V Buss bar(the load). The Blk to the Solenoid Bat+ lug(the source). Both go through the Bulkhead connector, into the fuse panel mating connector, then through the Main harness to the meter. I'd check in the bulkhead connectors first. One of the mating Twinlock pins in the fuse panel junction may be open or pushed rearward. I don't recall which of the 2 it is, inner or outer connector, but it has the 12G Red and 12G Brn and 14G Org wires in it.

Link to wiring diagram in HERE.

Rich

[John F.]

Re: Ammeter Replacement 66 coupe

Rich, thank you for your suggestions. I did check the bulkhead connectors and one of the pins was indeed pushed in. Looking at the firewall, it was the outboard connector and the top outboard pin in that connector. I managed to get it out into normal position and reconnect, but apparently the problem is something else as well. I guess I will have to dive deeper into the main harness.

John

[Richard M.]

Re: Ammeter Replacement 66 coupe

Rich, thank you for your suggestions. I did check the bulkhead connectors and one of the pins was indeed pushed in. Looking at the firewall, it was the outboard connector and the top outboard pin in that connector. I managed to get it out into normal position and reconnect, but apparently the problem is something else as well. I guess I will have to dive deeper into the main harness.

John

Ahh, too bad it wasn't that simple. edit....BTW, that's the Black/White, which is from the Horn Relay Buss bar.

To see which of the 2 it is at the meter if problematic there, use your voltmeter(use the meter pod as Ground to verify it) and + probe at each of the 2 terminals at the back of the meter. You should get ~12V at each. It may point you somewhere if not.

If you get volts on both.....

If you put lights on or some other load, the Black/White(12V load point at horn relay) should be a tad less than the Black(Bat+ source).

Rich

edit again....One more thought. The Black/White from the Meter/BH connector goes to the Horn Relay Buss Bar and ties to the same point as the 12G Red. There is also ANOTHER Black wire, which is Ground and should be attached to the Horn Relay mount Bolt/rad support metal/chassis. Be careful you don't inadvertently switch the 2.

I edited this about 5 times as I got colors wrong the first time. I think I got it right this time. Sorry for any confusion.

[Donald H.]

Re: Ammeter Replacement 66 coupe

I'm going to suggest that it could still be the bulkhead connector. I cleaned all of mine made sure all the pins were pulled out and reconnected and still had a problem with my meter. I don't know how to describe it, but the tip end of the pins can be bent together enough that the will not make contact with the mating pins. Take a small screw driver or something similar and spred all the pins out, both on the engine harness side and the fuse box side.

that solved my flakey battery meter.

Don

[Richard M.]

Re: Ammeter Replacement 66 coupe

I'm going to suggest that it could still be the bulkhead connector. I cleaned all of mine made sure all the pins were pulled out and reconnected and still had a problem with my meter. I don't know how to describe it, but the tip end of the pins can be bent together enough that the will not make contact with the mating pins. Take a small screw driver or something similar and spred all the pins out, both on the engine harness side and the fuse box side.

that solved my flakey battery meter.

Don

Yes good point(no pun intended). I sometimes use a small screwdriver and insert in the open tip and spread it open a bit more.

Rich