Progress, but temp and gas gauges dont work.

[66DartSedan]

SO I got my baby on her first movie "The Irishman" by Martin Scorsese as a BG car even without a good paint job. I've been ordering parts bolt by bolt, I and my mechanic been restoring the my 66 Dart Sedan. He's a good guy and he's sorta teaching me in a way by making me buy the parts myself and do the research but he'll do the labor if I'm not able to myself but I save $$ on buying the parts.

Well, the next thing on my list is getting the temp and gas gauges to work. This may be too complicated for me but Ill give it the old college try.

First thing I did was change my voltage regulator to the Electronic Solid state VR Mopar Voltage Regulator - Electronic Solid State with Correct Restoration Look | eBay


I got from furygt on ebay and installed it today. It looks great and OEM, but I got no change. Then I changed the fuses still nothing.

What should be my next step?

 

[66fyssh]

Fuel and Temp gauges work off of 5 volts that comes from a mechanical voltage regulator inside (yes inside) the fuel gauge. 12v goes into the fuel gauge and 5 volts powers the fuel gauge and goes over to the temp gauge.

There is a lot of information out there about doing a digital voltage regulator (7805) replacement. Here's one by Richard Ehrenberg Vintage Chrysler electrical repairs and updates (part 2)

Here's a pic during the repair of mine in a 66 Barracuda.

 

[66fyssh]

Your car looks great! And thanks for getting an a-body into a film!!!

 

[66DartSedan]

Fuel and Temp gauges work off of 5 volts that comes from a mechanical voltage regulator inside (yes inside) the fuel gauge. 12v goes into the fuel gauge and 5 volts powers the fuel gauge and goes over to the temp gauge.

There is a lot of information out there about doing a digital voltage regulator (7805) replacement. Here's one by Richard Ehrenberg Vintage Chrysler electrical repairs and updates (part 2)

Here's a pic during the repair of mine in a 66 Barracuda.

View attachment 1715137400

Thanks for all the info! How long of a job did that take you?

 

[RedFish]

66 Dart may not have the limiter built into the fuel gauge like the B'cuda has. Majority of inst' voltage regulators are a separate can/unit plugged into the back of the inst' panel. Regardless where it is, it cant function while the inst' panel dangles from its harness connectors. It needs chassis ground through the mounting screws or a added ground wire.

 

[66DartSedan]

66 Dart may not have the limiter built into the fuel gauge like the B'cuda has. Majority of inst' voltage regulators are a separate can/unit plugged into the back of the inst' panel. Regardless where it is, it cant function while the inst' panel dangles from its harness connectors. It needs chassis ground through the mounting screws or a added ground wire.

I've seen @slantsixdan talk about RTE limiter - rte , neither says they fit 66 Dodge Dart. Do you know any thing about it?

 

[slantsixdan]

It fits the '66 Dodge Dart, either as a direct plug-in or—I don't recall if the '66 uses or doesn't use the plug-in type. If not, then the limiter's built into the fuel gauge as described here. Either way, it works, only the installation method varies.

 

[66DartSedan]

It fits the '66 Dodge Dart, either as a direct plug-in or—I don't recall if the '66 uses or doesn't use the plug-in type. If not, then the limiter's built into the fuel gauge as described here. Either way, it works, only the installation method varies.

Which one? The ivr3 or ivr4?

 

[slantsixdan]

IVR-4.

 

[Mopar Tim]

1966 Dodge dart uses the plug in IVR. For sure, not in the gas gauge?

 

[KitCarlson]

Trouble shooting with a voltmeter is often more helpful than just swapping in parts.

The gauge circuits, are a series circuit. The series circuit starts with 12V then regulator, then gauge in series with sender, other lead of sender is ground. The gauges are thermal driven, and are slow to respond. The original instrument regulator is thermal too, and cuts on and off the 12V supply so the on duty cycle is about 5V.

Using a meter it is possible to measure the 12V that goes to the input of the regulator, and the 5V output of the linear regulator. The original regulators will pulse. The low reading on a gauge is when the sender is 75 to 73 Ohms, and max reading at 9 to 10 Ohms. Common 5W resistors for test.

The problem you have may be the 5V regulator circuit is improperly wired or shorted out, or wiring to sender open, or even ground connections open.

 

[66DartSedan]

Trouble shooting with a voltmeter is often more helpful than just swapping in parts.

The gauge circuits, are a series circuit. The series circuit starts with 12V then regulator, then gauge in series with sender, other lead of sender is ground. The gauges are thermal driven, and are slow to respond. The original instrument regulator is thermal too, and cuts on and off the 12V supply so the on duty cycle is about 5V.

Using a meter it is possible to measure the 12V that goes to the input of the regulator, and the 5V output of the linear regulator. The original regulators will pulse. The low reading on a gauge is when the sender is 75 to 73 Ohms, and max reading at 9 to 10 Ohms. Common 5W resistors for test.

The problem you have may be the 5V regulator circuit is improperly wired or shorted out, or wiring to sender

IVR-4.

OKay great, well I ordered one and Im gonna swap her out, see how it

IVR-4.

Welp, i ordered one and Im gonna do a swap, If anything itll be more steady than the mechanical version no? So i guess I have nothing to lose.

 

[RedFish]

The OEM mechanical instrument voltage limiters worked just fine. Everything that changed from 6 volt charging system to 12 volt charging system had/used one until they changed to 12 volt instruments. That's like millions of them in use for half a century.

 

[slantsixdan]

Breaker point ignitions worked "just fine", too, but electronic works better. Make-and-break voltage regulators worked "just fine", but electronic ones work better. Et cetera.

 

[RedFish]

Breaker point ignitions worked "just fine", too, but electronic works better. Make-and-break voltage regulators worked "just fine", but electronic ones work better. Et cetera.

No argument from me. All these new light bulbs work better, last longer, et cetera. If a solid state regulator will plug right in as easily as the OEM ( we twist these modern curly lightbulbs into the same socket ), then why not? The only remaining factor is cost. Will the solid state regulator last 20 to 30 years in a daily driver like the OEM mechanical version would ? We may never have that answer. good luck to all.

 

[mopartx]

My 66 Dart has gauge issues. At one point I was able to tap or push on the far left of the instrument cluster and they would work. However that hasn't worked in a while. I'm hoping to take mine apart in the next day or so. I'll update if I figure anything out.

 

[RedFish]

My 66 Dart has gauge issues. At one point I was able to tap or push on the far left of the instrument cluster and they would work. However that hasn't worked in a while. I'm hoping to take mine apart in the next day or so. I'll update if I figure anything out.

We pretty much know that's a loose connection. The limiter, light bulbs, must everything in the panel relies on a daisy chain of metal to metal contacts for chassis ground. This begins with the small screws that attach the printed circuit board to the housing. I forget which early a-body panel has a ground screw tucked underneath the limiter. Clean and secure every one of those contact points. Next is the screws that attach the housing to the dash. Adding a actual ground wire from circuit board to chassis is common practice.
Then there's the positive connections.... The limiter sits in some fancy/springy female spade clips designed to absorb shock, protecting the board. Some owners have soldered on side of these clips to the board to repair a connection. So those are some of the faults to look for.
Beware of the contact pins under the harness connectors. They may not be a problem now but they are only staked into the circuit board. They will bend, loosen, break. Move harness connectors off and on a straight as possible. Solder added at pins to board is common too.

 

[mopartx]

We pretty much know that's a loose connection. The limiter, light bulbs, must everything in the panel relies on a daisy chain of metal to metal contacts for chassis ground. This begins with the small screws that attach the printed circuit board to the housing. I forget which early a-body panel has a ground screw tucked underneath the limiter. Clean and secure every one of those contact points. Next is the screws that attach the housing to the dash. Adding a actual ground wire from circuit board to chassis is common practice.
Then there's the positive connections.... The limiter sits in some fancy/springy female spade clips designed to absorb shock, protecting the board. Some owners have soldered on side of these clips to the board to repair a connection. So those are some of the faults to look for.
Beware of the contact pins under the harness connectors. They may not be a problem now but they are only staked into the circuit board. They will bend, loosen, break. Move harness connectors off and on a straight as possible. Solder added at pins to board is common too.

Everything looks decent compared to others I've seen. My Alt gauge has a loose post but if I can't tighten it up I have another in a spare cluster I can try. Then I'll try to repaint the bezel. 2 questions since you seem to know more than myself. Here is a pick of the back of the cluster, should anything be attached to the spade off the back of the voltage reducer? Also the resistor attached to the cluster what does it attach to because it didn't look like it was hooked to anything when removed.

 

[RedFish]

A loose post in a amp gauge is not good at all. Definitely trash that gauge. I'll leave the mad bypass, volt gauge conversion topic to others.
The extra male spade on the limiter can is for a actual ground wire. That may not be the OEM limiter. Aftermarket replacement headlight switches also have a terminal for a ground wire. These terminals and ground wires were added to OEM in later year models so aftermarket reproduces the improved for every application.
The round thingy is a noise suppression capasitor. It prevents the limiters points like contacts making a pop noise in the radio speaker. That male spade goes into the center one of 3 female slots ( the 12 volt connection ) along with the heavy spade of the limiter. So yeah 2 males in the one female. To leave the one out could cause a loose connection since that springy female clip terminal has been stretched. A bit of history... A lot of guys would lay in the floor, whatever it took, to reach up under the dash and blind replace a failed limiter. That's how the terminal from noise cap' would get out and left out.

 

[mopartx]

A loose post in a amp gauge is not good at all. Definitely trash that gauge. I'll leave the mad bypass, volt gauge conversion topic to others.
The extra male spade on the limiter can is for a actual ground wire. That may not be the OEM limiter. Aftermarket replacement headlight switches also have a terminal for a ground wire. These terminals and ground wires were added to OEM in later year models so aftermarket reproduces the improved for every application.
The round thingy is a noise suppression capasitor. It prevents the limiters points like contacts making a pop noise in the radio speaker. That male spade goes into the center one of 3 female slots ( the 12 volt connection ) along with the heavy spade of the limiter. So yeah 2 males in the one female. To leave the one out could cause a loose connection since that springy female clip terminal has been stretched. A bit of history... A lot of guys would lay in the floor, whatever it took, to reach up under the dash and blind replace a failed limiter. That's how the terminal from noise cap' would get out and left out.

Ok, thanks for info. I'll check my extra alt gauge it there is no way to tighten up the existing gauge. I still haven't seen anything that could be causing my connection problem on the left side of my cluster. I'm going to address the alt gauge first and then repaint the front of the cluster and test it before I reinstall. Hopefully I can see what the other problem is if it's not fixed. Thanks again for the help and I'll probably ask again if come across another issue.

 

[mopartx]

Compared to my spare cluster this original cluster looks real clean.

 

[RedFish]

Amp gauge construction... Those steel studs were pressed into a brass bar and secured in a very dense molded plastic. You really should need to break it all to hell to have a "loose" post. I don't know that it has overheated or what. I know all the current inside the car goes through these posts and where they are pressed into the brass shunt/bar. I wouldn't even study a way to tighten a loose connection there.
The gauge has a magnet in it also. A good used gauge may have metal dust/debris in it. Compressed air will clear it.

 

[66DartSedan]

I went thru my firewall to check and see if everything was clean and grounded in the meantime. Can anyone tell me what these are?

 

[66fyssh]

First picture looks like a horn relay, the second picture is the ballast resistor. The ballast resistor is bypassed during cranking, but is in play during run to reduce the current to the coil and points. It can get warm during normal operation. Always a good idea to have a spare ballast in the glove box. They can go bad.

 

[66DartSedan]

First picture looks like a horn relay, the second picture is the ballast resistor. The ballast resistor is bypassed during cranking, but is in play during run to reduce the current to the coil and points. It can get warm during normal operation. Always a good idea to have a spare ballast in the glove box. They can go bad.

Thanks man! in the 3rd picture you see in the back ground a box that has a few wires in it, one of them says fuse link on a rubber tab, but do you know what he whole thing is called?