65 Dart Instrument Voltage Regulator Tips

[Austin Spencer]

I've done a bit of research on my new project, a 65 Dart GT Convertible, and I've come to the conclusion that my Instrument Voltage Regulator is bad. Symptoms I've had include a non-functioning Fuel and Temp gauge, and no lights illuminating the dash. I've got all of the indicators, oil light, turn signals, high beam indicator, and I've got a working Alternator gauge, but there's no movement in the Temp and Fuel gauges and no illuminating lights in the dash. I've hooked up 2 AA batteries to the gauges and both of them move, and I tested each bulb in the panel and they all light up, so I know it all works, but when it's hooked up in the car it seems those gauges and bulbs aren't getting power.

I've read that 65 has an internal regulator which is in the fuel gauge, and I can get an RTE external regulator and wire it in to replace it, and I see other threads on here as well as the guide on their site on how to do it, and it doesn't seem like too much of a challenge, however my current hurdle is getting my fuel gauge open. I've got it out of the instrument cluster, and the face plate is held with 2 small rivets. Is there any way to get this job done without drilling those out?

Another reason I assume it's the IVR is that I have a tester which I bought for testing my Mercury Cougar's gauges, which provides 3 different levels for testing gauges, and has an LED indicator which will flash with the IVR when it is functioning, and conveniently the Mopar and Ford IVRs both work with 5v, and when using it on my Dart the LED did not flash, nor did the gauges move. Convenient little tool.

 

[67Dart273]

We used to have a great guy on here "Redfish," who knew more about clusters than anyone I know. Another guy on here with GREAT BIG RED PRINT ran him off

This RTE website is the only decent how to I know of. Yes, the limiter on those girls is INSIDE the fuel gauge

You will have to paw around this site a bit

RTE Gauge Faq - rte

www.rt-eng.com

Basically, for reasons that escape me, the early girls and the Rallye clusters have the limiter INSIDE the fuel gauge.

HOW IT WORKS. All gauges have basically the same electrical specs. that is, you "could" swap the temp and oil gauge wires at the engine, and the oil gauge would now read as temp, and the temp gauge would now read as an oil gauge.

The limiter on all these girls WAS a deal similar to a signal flasher, which interrupts the 12V to pulse it in approximately 50% duty cycle, reducing the effective voltage by about half

In the girls with an INTERNAL limiter, the fuel gauge has THREE terminals. One is switched 12V from the ignition switch, which feeds power ONLY into the limiter. The limiter output is INTERNALLY connected to the fuel gauge AND branches off to a post on the rear of the gauge---so as to jumper power to the remaining gauges. The third post on the fuel gauge is of course the sender wire
YOU MUST (carefully and delicately) bend or block or otherwise remove the limiter contacts so that it can not function. Some advocate separating the contacts carefully, and putting a small glob of RTV or "Goop" (that IS the brand!!) to hold the limiter arm away from the contact.

Then, as shown on the RTE site, you must externally mount the new limiter and connect it's output to the post on the gauge which branches to the remaining gauges.

 

[67Dart273]

Dimmer controlled instrument lighting. That is a different circuit. Determine if ANYTHING works on the instrument dimmer. You do know? That the dimmer control on the headlight switch must be rotated to brighten them, "turn it CCW."

HOW THAT WORKS

The HL switch has TWO power sources, B1 an B2 at the switch. One comes (unfused!!) from the ammeter circuit and feeds ONLY the headlamps circuit.

The park, tail, and instrument lamps gets power from a fuse in the panel.

The HL switch internally feeds power to the dimmer control, and that dimmer controlled power comes OFF (out) of the switch on TAN. Tan goes TO the fuse panel, TO the small INST fuse, and then branches off to feed all dimmer controlled lighting on ORANGE wiring. So this includes the radio and depending on year, other accessories, shift quadrant, and of course the cluster.

If the cluster lamps don't work, but others do, such as the shift quadrant, the trouble is likely in the harness connector at the cluster, or just the sockets and bulbs themselves

If NO dimmer controlled lighting works, then see if there is power TO the INST fuse. The tail lights must work, the light switch must be in park or headlights, and the dimmer control must be "to the left." If there is no power there, might be a dirty/ burned up dimmer control, or bad connection at the light switch connector.

 

[Austin Spencer]

Thanks for the replies, after working on it a bit I got my gauges working, just needed to clean everything, and I was able to get the temp gauge working. I took out one rivet and swiveled the face plate off the fuel gauge in order to clean it, and it must have done something since I got my temp gauge working, but wasn't able to check my gas gauge.

However, now I've got a complete other problem that's worse, I've got no power anywhere with the battery hooked up.

From what I can tell I should have 12v+ and ground at the posts on the Alternator Gauge, but suddenly I've lost ground there, and now the ignition switch, headlight switch and everything else are dead. Is that correct, or is it not a ground post and 12v+ post?

I checked the dimmer, after getting my gauges working and before everything died just now, I was able to use the dimmer to control the bulb in the radio, but it had no effect on the instrument panel. I used the same batteries to check my gauges to check all the bulbs by putting the wires on the exposed parts of the circuit board, and they all worked there, so the problem must be between the dimmer switch and the connection to the circuit board, I'd assume since I was able to get the dimmer to control the radio bulb.

I've got 12 volts if I check from a interior screw to the positive post of the Alternator Gauge, so I'd assume my issue with everything else is just from not getting ground on the negative post of the Alternator Gauge?

 

[Austin Spencer]

Looking at the wiring diagrams, I can see that the wires from the Alternator Gauge go through the firewall connector, the red goes to the starter relay battery connection, and the black goes to the output of the alternator, so perhaps I've lost ground somewhere else?

This all happened after I disconnected the headlight switch from the wire in order to inspect it and see if I should order a new one, after unplugging it and plugging it back in everything has been dead.

 

[Professor Fate]

There is no "ground" terminal on the ammeter. It is a through circuit, both sides considered hot.
You probably lost your instrument ground when you pulled the cluster out, the circuits ground through the housing to dashboard to body ground. Try attaching a jumper wire from the cluster housing to a good ground, you'll most likely get your power back to the affected circuits.
Worst case scenario, you may have taken out a fusible link when you tested the ammeter to ground, if you did it when that circuit was live.

 

[Austin Spencer]

Thanks, yeah I just saw all that in the wiring diagrams and checking things, and after putting it together again I've got ground. I'll look into running a ground to the cluster to ensure I've got good ground.

I'm back to a spot where I've got no light in the instrument panel, but I can control the bulb in the radio. If I go all the way bright it cuts out, and my switch appears to be original so I'll probably order a new one since they're not too much, see if that changes anything.

For now, I'm going to use a Multimeter on the spots in the cluster connector that go to the bulbs and see if I can get any readings. Those bulbs don't go through the IVR so they should be 12 volts correct?

 

[67Dart273]

Thanks, yeah I just saw all that in the wiring diagrams and checking things, and after putting it together again I've got ground. I'll look into running a ground to the cluster to ensure I've got good ground.

I'm back to a spot where I've got no light in the instrument panel, but I can control the bulb in the radio. If I go all the way bright it cuts out, and my switch appears to be original so I'll probably order a new one since they're not too much, see if that changes anything.

For now, I'm going to use a Multimeter on the spots in the cluster connector that go to the bulbs and see if I can get any readings. Those bulbs don't go through the IVR so they should be 12 volts correct?

Use your head, here. If the radio is dimmer controlled, the light switch is doing it's job, and the INST fuse is routing power at least to the orange wiring branch-off. That means you should be looking at wiring problems to--at--and in the cluster. The cluster connector, the PC board(s), and the bulbs and sockets themselves. If the PC board(s) use a pin type connnector, it is common for the pins to work loos at the board traces. You must clean them, flux and solder. Some years you can get reproduction PC boards.

NOTHING has any connection to the IVR except the fuel, oil, and temp gauges

 

[67Dart273]

The ammeter circuit is problematic. The potential problems, are, the fuse link, the wire terminals going through the bulkhead connector, the connections at the ammeter, AND IN RARE cases, the "welded splice." This is a factory welded splice a few inches from the ammeter, in the black ammeter wire. This branches power off to the headlight switch, the fuse panel "hot" buss, and the feed to the ignition switch, maybe one or two other branches depending on year. Since you have the cluster out, it might be wise to inspect it.

 

[67Dart273]

I NEVER CAN REMEMBER there are one or two years of the "early girls" that eliminated the problem of feed through at the bulkhead connector. maybe 64? Has some large buss terminals through the connector that connect to the ammeter. These are identified by large terminals on each side of the connector for the black and red ammeter wires.

THIS thread seems to indicate that 65 is the "good" year

1964 Dart Bulkhead Connector

Does anyone have a '64 Dart that can get a good photo of the bulkhead connector under the hood? I am trying to decide if I can use '64 harnesses in my '63 since M&H makes them for the '64 (V8 only but stretching wires with a soldering iron and shrink tubing is easy). Thanks, Jim

www.forabodiesonly.com

More here. YES the 65 appears to have the heavy duty feed through busses for the ammeter circuit

Need a little help

So, I am having to replace some of the bulkhead connectors on my 1965 Dart. Have pulled the top and bottom plug from the firewall and am a little confused. Looking at the wiring diagram either numbers or letters for the connectors. Is the plug with the numbers on the top or bottom? Is the...

www.forabodiesonly.com

 

[Austin Spencer]

I've already checked the board, bulbs and socket and they do work, and I know the dimmer switch works, I'm going to be replacing it since it does not dim very well, it has dead spots and cuts out pretty often across its sweep.

I'm currently adding a ground wire to eliminate that as a variable, and once that's in place I intend to check the voltages at the pin connector and see if I'm getting anything there.

I've checked continuity from the connections at the bulkhead connector and there's no issues there, and I had continuity from the black wire of the ammeter to 2 of the fuses in the block.

 

[Austin Spencer]

Had to connect 2 ground wires to my circuit board to get all of the lights to illuminate, one to the light above the speedometer and one to the lights above the other gauges. It seems it all just needed a cleaning, but since I already removed a rivet I'll probably replace that with a small screw and nut so that later one if the IVR fails I'll have an easier time replacing it.

Thankfully all this ended up being was dirty connections all over the board, and poor grounding, but I'm glad to be more familiar with the instrument panel for the future.

 

[cudamark]

A couple of notes here....try using some contact cleaner on the dimmer potentiometer before you decide to replace it. Some aftermarket switches are of inferior quality these days and some don't even fit well in the dash. Also, should you need/want to go with the solid state IVR (recommended) you can sterilize the old IVR without removing the gauge face. I did it on my '66 by drilling a hole in the side of the housing and clipping the wire and bending the contact inside. Then just a piece of tape to cover the hole to keep the dust out. Loose pins on the circuit board are a common connection problem for the lights, as are corrosion on the socket contacts.

 

[Austin Spencer]

I saw in another thread your post about drilling a hole in the side, I thought about trying it but I ended up deciding to just drill out one rivet so that now the face plate can swivel off, and I'll probably replace that rivet with a small screw or something so that I can get back in there if/when the IVR fails.

It seems like the pins on my circuit board were fine, it just had no ground to the lights for the illumination, but did have ground to the indicator lights. A couple wires and it's all sorted out now. I did buy new wedge style sockets in order to eventually swap to LED bulbs, and saw a thread where slantsixdan recommended certain LED bulbs. I'll get to that eventually, for now I just want to get the thing driveable.

 

[cudamark]

The only problem with that is, when the IVR goes bad, it almost always locks on full 12 volts and fries the fuel and temp gauge.

 

[Austin Spencer]

Oh really? In that case I'll put in an order to RTE soon.

 

[MadScientistMat]

I've seen them also fail at zero volts. They don't always fail high