dash lights flickering even when headlight switch isnt on

[WH23G3G]

I've got this 65 Plymouth Valiant 170 that I finally got back running again and pretty much fixed besides body work. Now I've got some bugs to work out. I had all my gauges redone by Instrument Specialties Inc. I also installed a new dash harness from Year One and put all new fuses in the fuse box that was made into it. I also replaced the forward light harness/engine harness from Year One. So I got everything plugged in and double checked to make sure it's right. However when I start the car only one pod of the instruments lights up but it doesn't really light up it only lights up every couple seconds. Even when you turn off the headlight switch it still does it. When you turn the headlight switch to dim, the radio light doesn't work and the dome light doesn't work with the doors open either. All this stuff worked on my hacked wiring harness before I changed it all. I do remember though it was kinda hard to get everything lit up using the dimmer function on the headlight switch, it wasn't all the way turned to the right it had to be on a certain spot in the middle of turning it. I checked to make sure no fuses were blown and none are. The tail lights don't work but the headlights and turn signals work. What could be causing the instrument panel light to light up even with the switch turned off and to flash instead of staying illuminated?

[Ghoste]

Sounds like a short somewhere.

[b5blue]

Rotate the switch a bunch of times. The contacts get dirty.

[Dino]

Probably the rheostat.  When it gets dirty it'll act up.  Also check your grounds.  If it was a Charger I'd say check the turn signal switch as it can be the cause of non functioning brake lights.

[WH23G3G]

I turned the headlight switch back and forth a bunch of times and my dome light came on and my tail lights started working too. I wasn't able to verify if the dash lights quit flashing since it was so bright outside and I left before it got dark. My biggest problem is the non functioning temp and fuel gauges now. I had the gauges redone by Instrument Specialties, new year one headlight/engine harness, new year one dash harness, new Standard Ignition voltage limiter. I started the car up the gauges seemed to be working right and after idling and running around the yard about 5-10 mins I noticed the gauges were pegged as high as they could go. So I thought they were toasted. I swapped out the voltage limiter and the gauges don't seem to move except the fuel gauge a little. Then I swapped it out with one from RTE today and again only looks like the fuel gauge moves to the bottom of E eventhough I put 4.5 gallons in a new tank. After I put in the RTE limiter I did the Chrysler test with ignition switch on and hooked my test light to a good ground and to the temp sending unit and the test light did not light up at all. I double checked to make sure I had a good ground by probing the battery which lit it up. So if the temp sending unit doesn't light up at all with the ignition switch on what does that mean?

[Dino]

The temp sending unit's violet wire runs through the bulkhead connector to the wide plug that goes to the circuit board on the cluster.  I'll bet you the pin is loose, very common.  In fact, it sounds like there may be some more loose pins.  It's an easy fix but you're going to have to remove the cluster.  Then remove the circuit board from the cluster and clean it up, make sure all the pins are straight and solder them to the board on both sides.  That fixed all my issues!

[nh_mopar_fan]

I would run an extra ground from the back of the cluster as well.

I had similar issues with my wife's 66 Signet ragtop and the ground cleared that up.

By any chance are you running LED bulbs in that new cluster? Those are an issue. Get regular bulbs in there.

[WH23G3G]

I'm using regular bulbs. Where should i run a ground? I checked the pins when I had the cluster out.

[Dino]

Just to make sure: did you measure continuity between pins and ends of the copper runs?  the pins on mine seemed fine but not all made proper contact.  Once the board was cleaned and the pins soldered all was well.  I'm not saying you didn't check properly, just making sure we can scratch this step.

I don't see why running another ground would be necessary as every screw holding the cluster in the dash is ground but if you want it, anywhere from the metal cluster housing to anywhere on the dash frame or chassis will work.  Shorter is better.

[WH23G3G]

No I didn't do all that. I looked at the pins to make sure none were broken. I did notice the new year one round cluster plug was quite snug to get on. Just to make sure. When I've got the car running and the temp sending unit wire plugged in on the engine shouldn't it light up my test light if it's getting power? Could it have burned out the temp sending unit? I know the fuel sending unit connector barely stayed on the new sending unit just like it did on my Charger. They always fall off real easy. But I see the fuel gauge moves just a little bit when I turn the key on.

[nh_mopar_fan]

I did it because while every screw there is a ground, they are 50 years old and chit doesn't always tighten down as well as it did after all that time.