1965 instrument voltage regulator

[Watermelon Jack]

I have a new instrument voltage regulator to install on my 65, can't find it anywhere near the battery in the engine bay. Is this under the dash somewhere, if so, how hard is it to get at?

Thanks, Watermelon Jack

 

[Terry64HT]

It's under the dash above and to the right of the speedometer. Section 15 of the shop manual has the details. They tell you to remove the speedometer, but if you don't mind some skinned knuckles, you can replace it by removing the clock console (described in the same section). Once you have dropped the clock console, the regulator is to the left. Not easy to get to, but can be done.
Hope this helps
Terryw
64HT

 

[Watermelon Jack]

thanks, it still sounds like a bit of work, so I hope it is worth it.

 

[Terry64HT]

While it's awkward, it's not too difficult and worth it if your gauges are incorrect or not working.
Terry64HT

 

[Watermelon Jack]

Thanks, I don't like the way the ammeter keeps bouncing around and I don't trust the oil gauge as it reads too low as there is nothing wrong. I found the information in the manual as you described. Time to lose some flesh.

1965 Town Landau 70K original miles 99% fully loaded, all original

Others in my barn, 1969 MGB GT rolling restoration but otherwise 90% done, have participated in All-British runs for over the past 10 years,1969 Mustang Fastback Restomod 70% complete, someday she will fire up.

:driving

 

[Terry64HT]

The voltage regulator won't fix the bouncing ammeter, that's probably a ground issue. The regulator supplies 5 volts to the oil, gas and heat gauges. If only one is reading odd, chances are it's not the regulator.
Good luck
Terry64HT

 

[Watermelon Jack]

So I suspect the grounding issue is then related to somewhere on the dash? I was hoping the solid state version of the constant voltage regulator would cure some things. I have the wiring diagram manual , but where do I start looking for the grounds? British cars are notorious for the same problems (Lucas, Prince of Darkness)

 

[Terry64HT]

By ground, I meant the one from the battery to the frame and then to the engine block. I'd take it off and clean the area at the frame. The original ones were one piece from the battery to the block with a lug in the middle for the frame, but many have been replaced with two different wires. Oil and dirt gets between the lugs at the frame, making a poor ground.
I think in 65 power went from the alternator to the ammeter and then to the lights and ignition switch. Once power comes out of these, there's a ground for each item. It's not likely that any one thing would draw enough power to make the ammeter bounce in big swings.
Terry64HT

 

[Watermelon Jack]

Thanks, I will start in the engine bay and check everything. I hate the idea of disturbing the dash. Do you think teflon tape on the oil pressure sender would interfere with the grounding for that gauge? The manual says to use "an electrically conductive sealer". I installed an new oil pressure sender when I put on a new fuel pump. I do have a new wire for the sender to install as the original is a little shady.

 

[Terry64HT]

The oil pressure and temp gauges are grounded through the threads. Teflon tape would probably interfere, but the threading action probably has cut the tape enough for a circuit. You can check the ground resistance between the sensor just above the threads and the block. Teflon tape isn't supposed to seal a threaded connection, it's lubricant.
I mentioned a poor ground, but it wouldn't hurt to check the positive connections at the solenoid, battery and disconnect through the firewall. I recall that this connection sometimes corrodes.
Terry64HT

 

[Montana Tbird]

same issue with the constant voltage relay

I have a 65 bird with non working fuel gauge and temp gauge. I'm trying to feel for the existing voltage relay, and have removed the clock housing. Is the relay on the front or the side of the speedometer? I haven't had any luck using a mirror or feeling with my fingers. Any help would be greatly appreciated!

 

[Yadkin]

I have a 65 bird with non working fuel gauge and temp gauge. I'm trying to feel for the existing voltage relay, and have removed the clock housing. Is the relay on the front or the side of the speedometer? I haven't had any luck using a mirror or feeling with my fingers. Any help would be greatly appreciated!

If your gas gauge works then the voltage regulator works.

Ground out the sender wire at the temperature sender- it should send the gauge full hot. Same with the fuel sender.

 

[Terry64HT]

I believe the regulator was originally mounted to the back of the speedometer housing near the clock end, but if it was ever replaced was often moved to a more convenient location. To complicate things a bit more, it may even have been replaced with an aftermarket one that might not even look the same. Some of the earlier replacements were just a bare board just over an inch square. All you can do is fish around a bit. To make it even more fun, if you use a mirror with a metal frame, it will keep getting sucked to the speaker magnet....
Wish I could be of more help. I thought I had photos of my replacement, but they seem to have disappeared.
Terry
64HT

 

[Terry64HT]

Did you ever sort out the instrument voltage regulator problem? Things kind of died a few weeks ago.
Terry
64HT

 

[Montana Tbird]

I finally sorted out my problems with the gauges - I took the speedometer housing off, and the gauge cluster as well. The old voltage regulator under the speedometer was defective, and I could never have gotten it off, and the new one installed with the wires without having the gauge cluster out of the way. The second issue I had was self inflicted - when I was reassembling the dash after getting the vinyl recovered, I installed one of the leads on the instruments backwards. The lugs on the back of the gauge clusters are not marked for hot or ground, and the electrical diagram isn't too clear on it. So I put the gauge cluster on the test bench and tested each gauge, and marked the back of the housing with a Sharpie
as to the color of wire and also which lug is hot. After reassembling the dash (again!!!) everything works as designed.

 

[Terry64HT]

Glad to hear it. My 64 is now in winter storage and I'm in Florida accumulating the parts I need for next spring.
Not much left to do on it now.
Terry
64HT

 

[romans324]

My 65 Tbird gauges are all grounding out to the right of the gauges except the amp gauge which still works. I was Removing the safety convenient panel when the gauges all moved to the right when ignition is turned on. Prior to that all the gauges worked fine. Need help troubleshooting. Thanks. Jim.

 

[Yadkin]

Fuel level, water temp, and oil pressure gauges are on the same circuit. Fused 12 volt power goes to a Constant Voltage Regulator (CVR) that generates a constant 6 volts. Six volts goes to each gauge, and each gauge is grounded through a variable resistor (senders).

The gauges are all the same, just different printing and scales. The circuit powers a heating element that acts on a coil that moves the needle. Thus the dampening effect, or slow moving needle. To test each gauge, ground the wire (0 ohms) and the needle should move all the way (full, hot, or high).

It is unusual that all three are grounding out when you fiddled with a panel. I'd start investigating there.

 

[Montana Tbird]

found the problem

You are correct - upon rechecking all of the connections on the back of the gauges, one or more was incorrectly wired. Good old operator error! But everything works great now. Thanks

 

[romans324]

Not sure who Montana is?? But his reply to my question got on my log in reply space??. I’m still looking for the problem with my 1965 Tbird gauges all moving to the full right position upon ignition. I am Checking the fuse location 12 on the fuse panel today as one suggested. . Maybe it grounded out somehow. Thanks for the help. Jim