Rally Dash

-
S

seitz

Active Member
Joined
Jun 29, 2023
Messages
29
Reaction score
4
Location
canada
Hey Guys having trouble with my Rally Dash gauges and lights on my 70 Duster I only have the brake light that comes on on the dash every light on the cra works other than the dash lights including signals on the cluster.
I have a good ground on the dash so that dont apprear to be the issue i have teste all the light bulbs as well as the circuit board all have continuity. the plug on the back has power such as when i put signals on both signal wires have power at the plug. i have power on both wires that bolt to back of cluster also. Any ideas?? I should also mention that when i put the signals on the brake light has a dim flash to it. This makes me think ground but again i seem to have a good dash ground.
 
Check your chassis grounds @ every light and grounding wire
 
There is a voltage regulator located inside the fuel gauge. It allows 12v in and trims it down to approx 5-6V, that MAY be your problem. If it goes, the majority of dash "stuff" stops working.
 
4spdragtop said:
There is a voltage regulator located inside the fuel gauge. It allows 12v in and trims it down to approx 5-6V, that MAY be your problem. If it goes, the majority of dash "stuff" stops working.
Click to expand...
I have extra fuel gauges i will try it i did not think this would effect the lights only gauges. The cluster has two seperate boards that each run independantly the brake light runs off the one side and the hight beam light is off the opposite board. so each board is getting power i am gona pull the dash and run leads to it and trouble shoot it that way i guess. frustrating that this is all that is the last issue before i can drive the car.
 
The only lights in an inst' cluster that will work without chassis ground are brake and oil warning if so equiped. Those lights get their ground from remote switches. All others including hi beam get there ground through the cast inst' housing and vehicle body.
So if your inst' housing does have a ground to the dash via the mounting screws, that is only one link in a daisy chain ground path. Next probable culprit is a ground wire that jumps from body to engine block. It should be near fan motor or behind right cyl. head. It grounds the body to the engine so current path goes across the engine to neg' battery cable. That jumper wire is often left disconnected at engine change.
 
Yes all grounds are connected I have a ground at cluster also. I just went through wire diagram and see that the plug has one ground of the board plug iam thinking this could be the issue I will follow that wire and see where it goes I assume the firewall plug and go from there iam hoping this is the issue I don’t want to pull cluster back out if I don’t have too
 
How is the dash grounded, you say "I have a good ground, so did you add a pigtail? Maybe it is not connected to a ground point. Photos might be helpful

Did you add LED lamps? Most are polarity sensitive, although it does not seem likely that you got them all in reversed.

A multimeter and 12V test lamp should make short work of this.
 
seitz said:
the plug has one ground of the board plug
Click to expand...
This cluster board connector has NO ground wire.

This is the diagram from the 71 service manual, I can find no such diagram in my 70 manual. YOU MAY be misreading the legend at far left, where it says G1-18BK FEED and then GROUND below it.

Bear in mind that BLACK wires are NOT necessarily ground and in fact there are actually FEW ground wires in any of these cars Many of the lamps, the VR, alternator, and so on, are grounded directly and not through wiring.

71Rallye.jpg
 
Last edited:
WE REALLY need a good clear photo of the rear of your cluster. If it is difficult, take two overlapping shots and post them. On most clusters you can simply LOOK at the board traces and follow them, and determine which is what
 
67Dart273 said:
How is the dash grounded, you say "I have a good ground, so did you add a pigtail? Maybe it is not connected to a ground point. Photos might be helpful

Did you add LED lamps? Most are polarity sensitive, although it does not seem likely that you got them all in reversed.

A multimeter and 12V test lamp should make short work of this.
Click to expand...
I did a direct ground if I put a test light grounded to cluster I get power on power so it is grounded for sure builds are factory bulbs. I tested board with multi meter as I did with gauges all test fine. I am thinking it’s the ground wire on plug that grounds the board may be bad
 
seitz said:
I did a direct ground if I put a test light grounded to cluster I get power on power so it is grounded for sure builds are factory bulbs. I tested board with multi meter as I did with gauges all test fine. I am thinking it’s the ground wire on plug that grounds the board may be bad
Click to expand...
Reread what I posted. There is no cluster ground on the harness connector. All of these clusters were originally (poorly) grounded through the cluster mounting screws. Of course when things were new, this worked
 
seitz said:
Yes all grounds are connected I have a ground at cluster also. I just went through wire diagram and see that the plug has one ground of the board plug iam thinking this could be the issue I will follow that wire and see where it goes I assume the firewall plug and go from there iam hoping this is the issue I don’t want to pull cluster back out if I don’t have too
Click to expand...
I agree with above. You need to study OEM wiring diagrams. There is no actual grounding wire in either of the 2 harness connectors to the inst' panel. Early on in production, they did place a small ground jumper on the screw that holds noise capasitor to housing. It ended at radio support screw to dash if my memory serves. We've seen very few photo examples of this lil jumper. Their engineers and bean counters decided that was unnecessary time and coins. The pot metal inst' housing should find a ground through the few screws that hold it in the dash.
I'm wondering if there is a bunch of painting or powder coating in play here. That will interfere with ground path.
 
67Dart273 said:
This cluster board connector has NO ground wire.

This is the diagram from the 71 service manual, I can find no such diagram in my 70 manual. YOU MAY be misreading the legend at far left, where it says G1-18BK FEED and then GROUND below it.

Bear in mind that BLACK wires are NOT necessarily ground and in fact there are actually FEW ground wires in any of these cars Many of the lamps, the VR, alternator, and so on, are grounded directly and not through wiring.

View attachment 1716118170
Click to expand...
Thanks for this diagram its much clearer than what i have and i do see that number 8 is not a ground as i thought. I am going to have to pull cluster and go from there i add a ground from cluster to bare spot on the car so i would seem not to be a ground. Maybe as someone stated the bfuel gauge may be bad i have extra that i can try another one. I know its somthing simple but frustrating trying to pin point it. espeicialy when i have power at the plug
 
RedFish said:
I agree with above. You need to study OEM wiring diagrams. There is no actual grounding wire in either of the 2 harness connectors to the inst' panel. Early on in production, they did place a small ground jumper on the screw that holds noise capasitor to housing. It ended at radio support screw to dash if my memory serves. We've seen very few photo examples of this lil jumper. Their engineers and bean counters decided that was unnecessary time and coins. The pot metal inst' housing should find a ground through the few screws that hold it in the dash.
I'm wondering if there is a bunch of painting or powder coating in play here. That will interfere with ground path.
Click to expand...
if i put a test light on the screws that hold the cluster i have ground so to me that says cluster is grounded
 
seitz said:
if i put a test light on the screws that hold the cluster i have ground so to me that says cluster is grounded
Click to expand...
Lets clear up the misconceptions about that fuel gauge. This gauge has 3 contact studs on its backside where a typical gauge has only 2. Reduced voltage from a gauge voltage limiter goes in through the typical gauge and out opposite stud to a sender. Those 2 post gauges are mounted to the housing in such a way that they are isolated from chassis ground. So the reduced voltage can't go anywhere other than where it's supposed to go. The 3 post gauge has 12 volts going into it via the 3rd post at switch on because the voltage reducer or limiter is mounted inside that gauge. So this particular gauge must be mounted different from those others because reducer/limiter needs a chassis ground, or it doesn't function properly either. If you were to remove the fuel gauge from the housing yyou would find a slither of metal on its backside and a small unpainted spot in floor of housing for that slither of metal to contact. That is the 1st step of more or less same daisy chain of metal-to-metal contacts that create a ground path back to the battery negative post. Now I'm wondering do any of your gauges work? I'm also wondering why you don't have/use a proper meter. The basic test lamp might show you enough ground to light its tiny bulb yet not nearly enough to make a entire inst' panel work.
Anyway... back to my point here, I sincerely doubt the fuel gauge can have any effect on how turn indicators, illumination bulbs, etc..., work or not. Hope this helps.
 
RedFish said:
Lets clear up the misconceptions about that fuel gauge. This gauge has 3 contact studs on its backside where a typical gauge has only 2. Reduced voltage from a gauge voltage limiter goes in through the typical gauge and out opposite stud to a sender. Those 2 post gauges are mounted to the housing in such a way that they are isolated from chassis ground. So the reduced voltage can't go anywhere other than where it's supposed to go. The 3 post gauge has 12 volts going into it via the 3rd post at switch on because the voltage reducer or limiter is mounted inside that gauge. So this particular gauge must be mounted different from those others because reducer/limiter needs a chassis ground, or it doesn't function properly either. If you were to remove the fuel gauge from the housing yyou would find a slither of metal on its backside and a small unpainted spot in floor of housing for that slither of metal to contact. That is the 1st step of more or less same daisy chain of metal-to-metal contacts that create a ground path back to the battery negative post. Now I'm wondering do any of your gauges work? I'm also wondering why you don't have/use a proper meter. The basic test lamp might show you enough ground to light its tiny bulb yet not nearly enough to make a entire inst' panel work.
Anyway... back to my point here, I sincerely doubt the fuel gauge can have any effect on how turn indicators, illumination bulbs, etc..., work or not. Hope this helps.
Click to expand...
I finially got lights working ended up being the ground screws that hold the board in place had to wire wheel them all to get a good conection that sovle the light issue but still no gauges the all test good with a mulit meter. does the fuel gauge have a wire that is 12v going into harness that feeds it power? also what is volatge in the wores neede dto feed temp and oi gauge?
 
seitz said:
I finially got lights working ended up being the ground screws that hold the board in place had to wire wheel them all to get a good conection that sovle the light issue but still no gauges the all test good with a mulit meter. does the fuel gauge have a wire that is 12v going into harness that feeds it power? also what is volatge in the wores neede dto feed temp and oi gauge?
Click to expand...
OK, in the round harness connector the dark blue at top center is to fuel sender. A short distance counterclockwise is a blue with white tracer (about 10 o'clock position). This is 12 volts into the fuel gauge at switch on. This 12 volt supply along with the chassis ground at back of this gauge detailer earlier is all about the internal voltage limiter. The pulse voltage coming from that limiter jumps directly to the fuel gauge inside that gauge. This pulse voltage also comes out of the gauge at another of the posts so the printed circuit board can carry the pulse voltage to the water temp' gauge and the oil pressure gauge. The copper traces on these printed circuit boards are very simple to follow so you should be able to see and understand what I've described here.
And I must say I am so sorry I failed to mention those board mounting screws. I should have and could have saved you some headache. They have what is called a kept washer on them that rest against copper pads beneath. So that is in fact the first link in the daisy chain chassis ground path.
I spent 8 years of my life renewing these gauges and/or entire rally inst' panels before retiring. While in process I would use a water like safety flux (used in solder brass cane around glass, purchased at Hobby Lobby) to clean every brass contact point on the circuit boards. I used a wire brush in a dremel to spin and scrub those kept washers on all board mounting screw. I also cleaned all gauge posts and replaced the stamped tin speedy nuts on gauge posts with real 10-32 hex nuts and internal toothed washers on every gauge post.
Last step was to test every circuit on my workbench and calibrate every gauge to ensure customer satisfaction. I didn't keep a count on anything other that how many fuel gauges I renewed during those 8 years and I forget that now, either 332 or 352.
 
Last edited:
You know... I'm thinking the above could be too much information or it could be that I stopped short of everything I could type here in effort to help you. My best plan is probably to wait for your next question.
 
RedFish said:
You know... I'm thinking the above could be too much information or it could be that I stopped short of everything I could type here in effort to help you. My best plan is probably to wait for your next question.
Click to expand...
deffinetly not too much info much appreicated i went over the wiring diagram last night and highlighed each gauge wire i followed everything this morning with a clera head and found the 12v gas gauge wire was one place off on the plug going to an spot with no pin. now i have 5 volts at the gauges. my amp gauge the new Volt reg is bad so that gauge now works. the oil pres gauge the sending unit i have is for a oil light so i have the correct bell type coming. as for water temp i think its fine also. This Rally cluster has been very interesting to say the least. I have learnt lots and many things have come back to me been a few years since i did a restore to this magnitude on a mopar. Many things tend to slip the mind. LOL thanks for all your help Cheers
 
seitz said:
deffinetly not too much info much appreicated i went over the wiring diagram last night and highlighed each gauge wire i followed everything this morning with a clera head and found the 12v gas gauge wire was one place off on the plug going to an spot with no pin. now i have 5 volts at the gauges. my amp gauge the new Volt reg is bad so that gauge now works. the oil pres gauge the sending unit i have is for a oil light so i have the correct bell type coming. as for water temp i think its fine also. This Rally cluster has been very interesting to say the least. I have learnt lots and many things have come back to me been a few years since i did a restore to this magnitude on a mopar. Many things tend to slip the mind. LOL thanks for all your help Cheers
Click to expand...
GREAT! There is one thing I wanted to mention even though you didn't ask. About those thin tin speedy nuts holding the gauges to the board. Although they do have a fairly large footprint to the copper pad beneath, the reason for their use is how a engineers training and mind works. A weak nut suggests a weak foundation of what its screwed onto. Those studs a swedged into a thin piece of fiber board that will break easily. Turning the stud would damage the nichrome wire welded to head end of them.
If the stud was rusty or damaged, a service tech could cut that pizzy nut off, thus saving the board and gauge. The downside of that nut.., it's the weakest link in the positive current path since it contacts only one thread of a stud or bolt. All of that is the cause for my internal toothed washers and true hex nuts but I had to CAREFULLY chase the studs threads first and be very careful in tightening.
I all most forgot. The connector that attaches to a oil sender looks a lot like a female spade terminal. It sides onto a small round button atop that sender. It typically doesn't have an insulator on it, so if it should fall or get knocked off and lay to chassis ground bad things could happen to all of your guages. That connector is available online somewhere, but I can never recall who/where to find it. Just another coin well spent in my opinion. Someone here knows but are they following this thread. Fingers crossed.
Happy moparing
 
Last edited:
Jumping in here, any chance someone knows of an available barrel plug for the center of a rally cluster…?? Any help would be greatly appreciated..!! Thank…..Swingn’
 
The terminals in that connector are oval shaped so in oversized round holes. No retainers in there either. One could make that thing with any piece of plastic large enough. Connector had a locating tang in its center, nearly impossible to see when assembling. Better to put your locating reference at top, 12 o'clock, where dk blue fuel sender wire is, on the out side of your homemede connector.
 
RedFish said:
The terminals in that connector are oval shaped so in oversized round holes. No retainers in there either. One could make that thing with any piece of plastic large enough. Connector had a locating tang in its center, nearly impossible to see when assembling. Better to put your locating reference at top, 12 o'clock, where dk blue fuel sender wire is, on the out side of your homemede connector.
Click to expand...
10-4…..Good info…Thanks, wasn’t aware the connector receptacles were oval. Yes a home made connector is in my future. Thanks again Swingn’
 
You must log in or register to reply here.
-

Back
Top