Pulled apart the dash today to troubleshoot some A/C Heater blowing issues and also decided to figure out why my cluster wasn’t lighting up. Started looking around at the wires back there and found these two wires unplugged. Anyone know what they go to? 1977 f-100

Behind cluster

Left side of the heater/radio

 

The yellow connector is keyed 12V power. Normally only used to power OEM cruise control with one bullet connector. The other one can be the dome light connector, a single wire should be coming down from the dvrs side A pillar and connect to it. Does you dome light work?

Or is that lone green plug is over by the ign key side and or center of the dash, it is for the OEM radio power. BOTH are HOT. It is NOT one hot, one ground. Radio ground when installed and connected to the rear support strap.

Instrument cluster/dash lights inop, did you rotate the head light switch back and forth to make the dash lights full bright?

 

If that yellow is Cruise Control you just confirmed my suspicions then. My speedo cable has a speed control module on it but my steering wheel isn’t factory so I couldn’t confirm.

The green is most likely Radio then, my dome lights work fine.

The dash lights ended up just being the bulb sockets not having a good connection to the circuit board. I did make sure the **** was turned all the way up but they’re still very dim. Not sure if that’s normal

 

Did you turn the headlight switch all the way (counter clockwise ?) to just before the "click" that turns on the dome lights with the doors closed? That is full bright in the dash lights setting. Yes if the speedo cable is a 2 piece with a module and elec connector, then yes at least you have a CC speedo cable. OEM dash lights are notoriously dim in the 1st place. Might try some Hipo parts dash light bulbs. https://www.hipoparts.com/led-bulbs-gauge-light-kits/

 

I ran out to autozone and picked up some LED bulbs for the two gauge lights. Much better!

 

Glad to hear that, what part #, $ and you do know that are directionally installed. So you got it correct the 1st time.

 

194SYLLED-2 Sylvania
$16.99

I did read that on other posts but I apparently put them in right the first time bc they both lit up