Quick instrumentation illumination questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

shuttermutt · 01-03-2004, 08:02 PM

First, are the bulbs in the instrument cluster wired in series or parallel? In other words, if one bulb burns out, does it take out one entire side of the dash?

Second, are the heater and A/C controls on a 67-72 (factory A/C) supposed to be illuminated? If so, are they the same 194 bulbs or are they different? Where are they located?

Thanks!

*rage'nrat638* · 01-03-2004, 08:25 PM

yea the heater controller is lit....one on each end 194 bulbs

i do not think that one bulb out kills the rest....
was not the case on mine....

724x4a/cchevy · 01-03-2004, 08:27 PM

The gauge panel lights are wired up in a parrallel circuit. If one goes out, it wont effect the rest of them.

shuttermutt · 01-03-2004, 08:31 PM

Bummer! It appeared that only one bulb was dead on the left-hand side of my dash yet the entire left-hand side was black. It was still too light to see if replacing the 3 bulbs I could find did the trick or not. Now that it's dark, I'll check 'em and see. Guess I'll dig around for those heater control bulbs, too.

724x4a/cchevy · 01-03-2004, 08:37 PM

If you look at your heater control, There is a hole right behind where it says defrost,air,heat. Right behind those words there is a hole, or a bulb housing, Try replacing that bulb. That display should light up when you turn your headlights on.

724x4a/cchevy · 01-03-2004, 08:38 PM

If your truck is a/c ther is a hole on each side of that display!

shuttermutt · 01-03-2004, 09:02 PM

Yep, it's an A/C truck. I replaced the right-hand (passenger) side bulb, but no love. I've got a couple of loose connectors up there, though. I'll have to troubleshoot when I have daylight. In the mean time, I've got my instrument lights working again. Well, except for the one near the oil pressure gauge. I think I'm missing one of those neat-o bulb holders for that one.

01-03-2004, 08:02 PM	#1
shuttermutt Don't say "Oops!", Doctor Join Date: Nov 2003 Location: Houston, TX Posts: 677	Quick instrumentation illumination questions First, are the bulbs in the instrument cluster wired in series or parallel? In other words, if one bulb burns out, does it take out one entire side of the dash? Second, are the heater and A/C controls on a 67-72 (factory A/C) supposed to be illuminated? If so, are they the same 194 bulbs or are they different? Where are they located? Thanks! __________________ 'Mutt 1968 CST LWB: R.I.P. 1967 Chevelle: TPI 454 beast 1967 C10 SWB: Claimed when Bumpster didn't put it on his list

01-03-2004, 08:25 PM	#2
rage'nrat638 Account Suspended Join Date: Mar 2003 Location: THE FALL GUY CHICAGO IL Posts: 5,883	yea the heater controller is lit....one on each end 194 bulbs i do not think that one bulb out kills the rest.... was not the case on mine.... Last edited by rage'nrat638; 01-03-2004 at 08:31 PM.

01-03-2004, 08:27 PM	#3
724x4a/cchevy Self-proclaimed LED man Join Date: Nov 2003 Location: Harrisburg, Missouri Posts: 1,021	The gauge panel lights are wired up in a parrallel circuit. If one goes out, it wont effect the rest of them. __________________ My LED Website My Photobucket Album of LED's Ask me about hand-made custom L.E.D brake and reverse lights. <- LINK I also do LED: -Third Brake/Cargo -Brake (truck and burb) -Reverse (truck and burb) -67-68 Front Turn Signals -69-70 Front Turn Signals -71-72 Front Turn Signals -GMC Front Turn Signals I can also do custom lights for other vehicles....i did a set for a AMC Gremlin once Norwood Survivor

01-03-2004, 08:31 PM	#4
shuttermutt Don't say "Oops!", Doctor Join Date: Nov 2003 Location: Houston, TX Posts: 677	Bummer! It appeared that only one bulb was dead on the left-hand side of my dash yet the entire left-hand side was black. It was still too light to see if replacing the 3 bulbs I could find did the trick or not. Now that it's dark, I'll check 'em and see. Guess I'll dig around for those heater control bulbs, too. __________________ 'Mutt 1968 CST LWB: R.I.P. 1967 Chevelle: TPI 454 beast 1967 C10 SWB: Claimed when Bumpster didn't put it on his list

01-03-2004, 08:37 PM	#5
724x4a/cchevy Self-proclaimed LED man Join Date: Nov 2003 Location: Harrisburg, Missouri Posts: 1,021	If you look at your heater control, There is a hole right behind where it says defrost,air,heat. Right behind those words there is a hole, or a bulb housing, Try replacing that bulb. That display should light up when you turn your headlights on. __________________ My LED Website My Photobucket Album of LED's Ask me about hand-made custom L.E.D brake and reverse lights. <- LINK I also do LED: -Third Brake/Cargo -Brake (truck and burb) -Reverse (truck and burb) -67-68 Front Turn Signals -69-70 Front Turn Signals -71-72 Front Turn Signals -GMC Front Turn Signals I can also do custom lights for other vehicles....i did a set for a AMC Gremlin once Norwood Survivor

01-03-2004, 08:38 PM	#6
724x4a/cchevy Self-proclaimed LED man Join Date: Nov 2003 Location: Harrisburg, Missouri Posts: 1,021	If your truck is a/c ther is a hole on each side of that display! __________________ My LED Website My Photobucket Album of LED's Ask me about hand-made custom L.E.D brake and reverse lights. <- LINK I also do LED: -Third Brake/Cargo -Brake (truck and burb) -Reverse (truck and burb) -67-68 Front Turn Signals -69-70 Front Turn Signals -71-72 Front Turn Signals -GMC Front Turn Signals I can also do custom lights for other vehicles....i did a set for a AMC Gremlin once Norwood Survivor

01-03-2004, 09:02 PM	#7
shuttermutt Don't say "Oops!", Doctor Join Date: Nov 2003 Location: Houston, TX Posts: 677	Yep, it's an A/C truck. I replaced the right-hand (passenger) side bulb, but no love. I've got a couple of loose connectors up there, though. I'll have to troubleshoot when I have daylight. In the mean time, I've got my instrument lights working again. Well, except for the one near the oil pressure gauge. I think I'm missing one of those neat-o bulb holders for that one. __________________ 'Mutt 1968 CST LWB: R.I.P. 1967 Chevelle: TPI 454 beast 1967 C10 SWB: Claimed when Bumpster didn't put it on his list



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