Lost my Fuel and Temp Guages at the dash in my 67 Dart

[RatRod]

Back story: A few months back I had power locks and a viper alarm system installed on my 67 Dart. It's a California car in very good shape and is a daily driver.

Upon leaving the alarm install shop I got about half way home and noticed my fuel and temp gauges weren't working anymore. Turned around and went back to the install shop to fix what ever they broke. So they proceed to hem and haw but finally agreed to look at it; first thing they did was remove the fuse box and put it back in and that worked. So I left only to find the problem reoccurring again and again over the next few weeks. The gauges would work and stop, sometimes come back on by themselves, sometime not. Everything else works fine.

Fast Forward:
What I've done is wiggle the fuse box with slight upward pressure and have gotten the gauges to come back on a few times. This has worked over the last several weeks. That doesn't seem to work anymore.

I have gone thru the wiring cluster around the fuse box a few times and cant find a loose or pinched wire anywhere. The fuse box will not come down far enough to really see what is going on in there on the wire side, so I'm blind there. It looks like the fuses are all good but I'm going to replace the one fuse that links to these wires anyway, but that is a long shot as the problem is intermittent and if it was a fuse problem, it wouldn't just come back on like that.

The way I understand the wiring diagram, the fuel and temp guages go into the same fuse, so maybe I have a bad connection there in the fuse box its self? I'd like to visually see that but I cant get the fuse box in that position because the wiring connectors and such are all up against it. Is there a trick to getting the fuse box in a position so you can see the wiring side?

The wiring is solid in this car so rewiring or going crazy like that doesnt make sense, so I'm not going there.

This is a loose wire or connection issue and I want to confirm I'm on the right track.

Any thoughts or prayers (lol) would be helpful.

 

[cudamark]

The instrument panel voltage limiter may be going out. I'd get one of the new solid state ones whether it's currently the problem or not. Most of the time when they fail, they fry the fuel and temp gauges.

 

[Dana67Dart]

If moving the fuse box causes the the problem to come and go I would suspect the pin on the back of the cir board on the gauge cluster.

The path goes as the following.

FROM the ignition switch a black wire goes to a splice.

From the splice it goes to a pink wire to the wiper switch and to 3 black wires. One TO the signal flasher, one TO the fuse block where it turns to red with a tracer and goes TO the radio, the third goes TO the instrument panel to feed 12v to the IVR.

So the power for all these things does not come from the fuse block it comes from the ignition switch and the feed TO the ignition switch comes from the main splice from the alternator.

There are no fuses in this path (except TO the radio)

So wiggling the fuse block is most likely wiggling wires under the dash causing the open connection to the gauge cluster.

You can check if the radio, turn signals, or wipers work or cut out when wiggling the fuse block

 

[67Dart273]

The gauges ARE NOT FUSED. The power for them comes off the (EDIT) Q2 black ACC accessory feed from the ignition switch, up to the cluster, and then goes through the IVR or instrument regulator.

IT MAY BE that the dash is suffering a poor ground, or just poor connections at the harness connector for the clusther (the board connector(s) which is VERY common. The pins of the connector come loose and corroded at the board and need to be soldered.

Try tightening (careful) the dash mounting screws to see if that makes a difference

WHAT ALL WAS wrong with my 67

1....Cluster pins were loose and in 2 cases broke. I actually just soldered wire leads to the PC board traces and converted to a couple of Molex style connectors
2...IVR was iffy and bad, replaced it with a solid state one
3...Contacts on the board where the IVR fits were not making good contact with the IVR. You must solder jumpers from the board traces to the contacts
4....Gauge studs were loose/ corroded. Replace the gauge stud nuts with real nuts, and tighten/ loosen/ tighten them a couple times to "scrub" the board traces clean where they contact
5....Ground. This is a problem. OEM clusters were grounded (poorly) by the mounting screws, and now these are so old, that rust/ corrosion has taken it's toll. Fasten a ground to a common point on the cluster, and bolt it to the dash frame or cluster support.

BE CAREFUL when working under the dash. Fuse protection ESPECIALLY on the older cars is poor, and there are circuits that ARE NOT FUSED, other than the main fuse link, which is poorer protection yet

NONE of the ammeter circuit is fused, the ignition switch power, or the main power to the headlight switch. DISCONNECT the battery ground when you are under there, unless you have "rigged" it carefully to make a test.

If you do not have a manual/ diagrams, go over to MyMopar.com and download the manual and also go to the wiring section, and download the 3rd party diagrams. These are NOT factory, and sometimes leave out details, but can be an aid to following circuits.

 

[67Dart273]

The relevant parts of the inst panel diagram. Top diagram find "ignition switch near the top. See ammeter just to the right. NOT FUSED. Off the bottom R6A BLACK comes off the ammeter to the splice a bit to the left. NOT FUSED and this is known as the WELDED SPLICE. J1 comes off that and up to the ignition switch. This is the main power going INTO the switch. Q2 comes off the ignition switch and down BLACK Notice it goes down to a splice. Now refer to the bottom diagram which overlaps

Notice the splice, top left of page, with Q2 coming down. This is switched ACC (accessory) power from the ignition switch. Notice G1 BLACK coming off and going down. Notice it goes down and over to G1 of a terminal on the cluster, inline connector, and then follow the dashed line over to the "external voltage limiter" and then to the fuel and temp gauges.

 

[Dana67Dart]

The power for them comes off the (EDIT) Q2 black ACC accessory feed from the ignition switch

I was about to post photos from the 67 dart wiring harness and ignition switch I have loose in my garage.

Thanks for your edit, saved me a bunch of time.

 

[RatRod]

If moving the fuse box causes the the problem to come and go I would suspect the pin on the back of the cir board on the gauge cluster.

The path goes as the following.

FROM the ignition switch a black wire goes to a splice.

From the splice it goes to a pink wire to the wiper switch and to 3 black wires. One TO the signal flasher, one TO the fuse block where it turns to red with a tracer and goes TO the radio, the third goes TO the instrument panel to feed 12v to the IVR.

So the power for all these things does not come from the fuse block it comes from the ignition switch and the feed TO the ignition switch comes from the main splice from the alternator.

There are no fuses in this path (except TO the radio)

So wiggling the fuse block is most likely wiggling wires under the dash causing the open connection to the gauge cluster.

You can check if the radio, turn signals, or wipers work or cut out when wiggling the fuse block

Good information, all other devices work perfectly including the alarm and power locks. Where exactly is the pin you refer to located and how can I get to it?

 

[RatRod]

Both gauges, fuel and temp, always go out at the same time but the rest work. As I understand it, The fuel and temp gauge each have a wire so how can they both go out at exactly the same time? There must be a common intersection of some kind.

I did remove the dash screws yesterday and pulled the dash out about an inch, got scared and put it back in. I need advice on how to work on the instrument panel before I go further with that.

As Dana67Dart suggested it seems like a ground or a loose connection in the instrument panel, what connection would affect both gauges besides a ground? Understand the IVR unit could be the culprit, BTW where do you get those?

I've got an old dash that was originally in the car, are the four pins in the upper right the ones that i should be looking at?


5....Ground. This is a problem. OEM clusters were grounded (poorly) by the mounting screws, and now these are so old, that rust/ corrosion has taken it's toll. Fasten a ground to a common point on the cluster, and bolt it to the dash frame or cluster support.

Dana67Dart - Can the ground wire go anywhere on the back of the dash?

 

[MadScientistMat]

The metal box in the lower left side of your photo is a voltage regulator (AKA voltage limiter) and provides a 5V feed for both the fuel gauge and temperature gauge. Most of the time when both fail at once, it's the regulator.

 

[trapster]

These things can be frustrating , but the dash wiring was not, in my opinion, designed to be out in the weather for 50 years, that being said, any movement or handling of the wires can cause disconnections or faults and I wouldn't be upset at the installer for this happening. If they fried a bunch of wires then I would have issue. It wouldn't hurt to remove the cluster and give all of the contacts a good cleaning. be carefull not to damage any traces, I would use a pencil eraser to cleanup around the lights and the studs.

 

[RatRod]

These things can be frustrating , but the dash wiring was not, in my opinion, designed to be out in the weather for 50 years, that being said, any movement or handling of the wires can cause disconnections or faults and I wouldn't be upset at the installer for this happening. If they fried a bunch of wires then I would have issue. It wouldn't hurt to remove the cluster and give all of the contacts a good cleaning. be carefull not to damage any traces, I would use a pencil eraser to cleanup around the lights and the studs.

I totally agree with you and that is why I'm handling this myself; I knew there was a chance of this when i decided to to the alarm install. The whole cluster of wires they installed are right there by the fuse box and there are a lot them.

 

[cudamark]

I totally agree with you and that is why I'm handling this myself; I knew there was a chance of this when i decided to to the alarm install. The whole cluster of wires they installed are right there by the fuse box and there are a lot them.

It could be that when the dash harness was moved around, there may have been a strain on the dash circuit board plug causing a bad connection. It's easy to loosen one of those pins in the circuit board.

 

[Dana67Dart]

Both gauges, fuel and temp, always go out at the same time but the rest work

There must be a common intersection of some kind.

The 12v feed to the IVR will do that.
The pin (red dot) or the slot (red dot) can do that
The pins are circled in red and are notorious for failure.

I did remove the dash screws yesterday and pulled the dash out about an inch, got scared and put it back in

It is a challenge to remove the dash cluster.

1. Easiest is to remove the front seat/s
2. The steering column
3. Unscrew the fuse block from the dash
4. And tape off the dash and the switches to protect from scratches.
5. Disconnect the speedo cable
6. Remove the dash screws and tip the cluster out as much as possible
7. Remove the nuts on the ammeter gauge
8. Carefully remove the two rectangular connectors
9. There is a clip above the speedo cable that holds the wire harness in place it moves straight forward of the car to move it off the clip.

Then the cluster can come out of the car.

NOTE:
the wires, connectors, nuts, the clips etc are all old and can be brittle.



Important Note
When the cluster is unscrewed there is no ground to the cluster and you can / will fry the gages

As Dana67Dart suggested it seems like a ground or a loose connection in the instrument panel, what connection would affect both gauges besides a ground? Understand the IVR unit could be the culprit, BTW where do you get those

The green dot on the board is a ground point there are several others.

 

[Dana67Dart]

These are corny as hell but very informative



Google "Chrysler master technicians service video"

the videos are typically organized by year 66-10 is 1966 October.

the topics are what to look at.
Many videos from 64 thru 76 are the ones that will most pertain to our cars

 

[RatRod]

Wow, this is a lot of good information and I really appreciate the time you have taken out of your day to do this. Especially over the holidays.

So I took Trapsters advice and went back thru the wiring cluster looking for bad connections and such. First thing I found was the tach was wired funny. The green and red wires were good but the ground wire was mated to a wire going up under the dash, the orange wire i think., using a plastic clip. I unhooked that. Tach works fine now, before it was intermittant too.

The next thing I noticed was the purple wire right next this plastic clip was gouged and showing a small amount of bare wire, which I taped.

Hooked the battery back up and started her up and everything works now. Hopefully I'm out of the woods on this one, we'll see.

Thank you all again.

 

[RatRod]

Theses responses to this post are professional in their content and diction. No grammatical errors, all cap typing or nasty comments.

Very well done. Thank you

 

[trapster]

I assure you sir any proper grammar or spelling on my part is purely by happenstance


Merry Christmas.