Hello everyone I am a new owner of a 1971 Plymouth scamp. I was doing some work on my dash none of the dash lights would work. So I took it out cleaned it and put all new bulbs in. And when I put out back in the only light that would work that the right turn signal light any ideas?
Dash lights not working
- Thread starter kuldips
- Start date
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Post some photos
Did you have the cluster grounded during testing?
Nothing jumps out, are you sure the terminals are in the correct slots?
Your copper traces look oxidized but not bad
I just cleaned this up with a pencil erasure and some contact cleaner.
It was really bad, your looks like erasure would be enough.
Nothing jumps out, are you sure the terminals are in the correct slots?
Your copper traces look oxidized but not bad
I just cleaned this up with a pencil erasure and some contact cleaner.
It was really bad, your looks like erasure would be enough.
Where any of the screws touch the cir board will do
Do you even know if the dash lamps are getting power? The dash dimmer controlled lamps are a bit of a trick.
The headlight switch has TWO sources of power. B1 ONLY powers the headlights, comes off the ammeter black wire circuit and IS NOT FUSED. The headlights circuit is sort of protected by a breaker in the light switch.
The second power source, B2, comes from the fuse panel, and operates the park, tail AND DASH lamps
The dash lamp power in the switch, coming from the tail/ park circuit, goes to the DIMMER control which must be twisted to the left to get brighter. Twist/ work, jiggle that to be sure it is not dirty. "Working" it vigorously helps clean the control.
THEN the dash light power leaves the light switch on TAN and goes TO the fuse panel INST (instrument) switch, and from there to all dash dimmer controlled lighting, including the radio, etc.
TEST your cluster out of the rig first. And as Dana said, ADD a separate ground wire.
Since you have it out you should consider doing some other work. Loosen/ tighten the nuts on the gauges to scrub them clean and be sure they are not loose. Consider replacing the gauge regulator/ limiter with an RTE or other solid state replacement. Solder jumpers across the IVR contact fingers to the PC board traces. Likewise, inspect, clean and solder any harness connector pins that are the slightest bit loose. They are sort of riveted/ swedged iin place, originally.
Clean the copper PC board pads around the lamps. If you can find an abrasive eraser, that works. Likewise clean and inspect the lamp socket contact fingers and bend them if necessary, for better contact.
The headlight switch has TWO sources of power. B1 ONLY powers the headlights, comes off the ammeter black wire circuit and IS NOT FUSED. The headlights circuit is sort of protected by a breaker in the light switch.
The second power source, B2, comes from the fuse panel, and operates the park, tail AND DASH lamps
The dash lamp power in the switch, coming from the tail/ park circuit, goes to the DIMMER control which must be twisted to the left to get brighter. Twist/ work, jiggle that to be sure it is not dirty. "Working" it vigorously helps clean the control.
THEN the dash light power leaves the light switch on TAN and goes TO the fuse panel INST (instrument) switch, and from there to all dash dimmer controlled lighting, including the radio, etc.
TEST your cluster out of the rig first. And as Dana said, ADD a separate ground wire.
Since you have it out you should consider doing some other work. Loosen/ tighten the nuts on the gauges to scrub them clean and be sure they are not loose. Consider replacing the gauge regulator/ limiter with an RTE or other solid state replacement. Solder jumpers across the IVR contact fingers to the PC board traces. Likewise, inspect, clean and solder any harness connector pins that are the slightest bit loose. They are sort of riveted/ swedged iin place, originally.
Clean the copper PC board pads around the lamps. If you can find an abrasive eraser, that works. Likewise clean and inspect the lamp socket contact fingers and bend them if necessary, for better contact.
70SwingerGuy
Long Haired Freaky Person
I guess an obvious question would be, what were you doing to the dash, did they work before, and did you check the fuses?
Did you bench test the lights and gauges before assembly? Are these stock replacement bulbs? The circuit boards are grounded to the cluster and the cluster is grounded to the car. Lastly, is that light circuit receiving power through the nine pin connector?
The only ground, originally, is the OEM mounting screws for the board to the cluster, and then in turn, the cluster screws to the dash frame, which is poor after all these years. Put a pigtail on and bolt to the column support or dash frame
Dave999
Well-Known Member
lights won't work until frame of cluster is touching frame of car to earth it. or bolted back in place
any light with 2 wires might work but most have 1 and use the cluster and circuit board as their negative connection
any light with 2 wires might work but most have 1 and use the cluster and circuit board as their negative connection
The 1 turn indicator is also chassis grounded like illumination. Only bulbs with 2 wires are oil warning and BRAKE . There is a way to bypass the dimmer rheostat and have full on illumination but a new switch shouldn't break the bank.
PINOUT
"A" Switched 12V in RUN and maybe in ACC
"B" Fuel Sender
"C" Temp Sender
"D" Cluster illumination, should have 0-12V when the headlight switch is pulled out to the first or second position DEPENDING on the turn of the dimmer rheostat
"E" High beam indicator
"F" Drivers side turn signal indicator
"G" Pass side turn signal indicator
"K" Brake Warning Light
"L" Oil Warning Light
"5-6V IVR output" is shared by the Temp and Fuel gauges
"IVR Ground" is also the ground for the far right Dash Illumination bulb
There are 2 more ground screws one by the lower left "Dash illumination" and one by the lower right "Dash Illumination"
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This is the ivr I got wich is the one on the dash 1966-1974 Instrument Voltage Regulator For Dodge Challenger Charger Dart Cuda Satellite | Custom in the description is said is was for 72 scamps and newer but I thought it would be ok since it the same dash and stuff but I don’t know if that really matters and then I just ordered a new headlight switch as well. Another problem I was having was when I plugged in the dash out of the mounting place to test is the gas gauge started to work but when I put in the dash and plugged it in the gauge stopped working but it has never worked as long as I’ve owned the car
I don't think a mechanical voltage limiter can work without chassis ground. A solid state regulator can pass full 12 volts without chassis ground if it doesn't have safeguard built in (like RTE claim to incorerate in yheir unit). I have no clue what inside the can you have.
All 3 grounds have to be grounded for all of the bulbs to light
That looks like an electro- mechanical ivr and it must be grounded or you will provide 12v to the gauges and burn them out.
Watching to learn about the gauges
Are your dash lights led by any chance?
What have you done in the way of troubleshooting/ testing? As I told you --you must make sure you have power out of the dimmer circuit.
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