dash light problem - The 1947 - Present Chevrolet & GMC Truck Message Board Network

KWinBigE · 02-05-2003, 09:16 PM

First, I just bought a 71 Custom 10 and I sure appreciate what a wealth of knowledge there is on this board. Already picked up a lot of good info.

But.....

Here's one I haven't seen before.
The dash lights on my '71 work but are real dim. I turn the knob all the way just short of the dome light coming on and they get a little brighter but still very dim. All external lights and signals work as advertised.

Here's some possible clues.
Both turn indicators come on (and stay on) when I turn on the lights, but the signals and flashers still work fine.
The dash lights are even dimmer when the high beams are on.
The dash was replaced with a tach dash (before I got the truck).

I'm thinking it might be a printed circuit board problem?

Any suggestions for troubleshooting further will be appreciated.

Thanks,

Kim

JimKshortstep4x4 · 02-06-2003, 09:56 AM

Everything that you describe indicates a ground problem. The dash gets its ground through the connector that plugs into the dash. I would suggest adding a separate ground wire and attach it to the metal back of the dash.

Jim

cdowns · 02-06-2003, 10:16 AM

Adding an additional ground wire is a good idea if that doesnt help you could always try new bulbs

**1970 CST Short Wide** · 02-06-2003, 01:06 PM

I had exact same problem. It was a ground on the circit board. I found it by accident when I grounded the unit while trying to figure it out. Just a loose ground, now they work PERFECT

GMC Jim · 02-09-2003, 11:16 PM

I replaced the #194 lamps with #168 lamps which are 3 CP compared to 2 CP... ( 1/3 brighter! )... leave the headlamp ho/lo indicator lamp with the original 194 lamp...

02-06-2003, 10:16 AM	#3
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Adding an additional ground wire is a good idea if that doesnt help you could always try new bulbs __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

02-06-2003, 01:06 PM	#4
1970 CST Short Wide Senior Moment Join Date: Mar 2002 Location: Pittsburg Ca Posts: 4,215	I had exact same problem. It was a ground on the circit board. I found it by accident when I grounded the unit while trying to figure it out. Just a loose ground, now they work PERFECT __________________ 1970 CST LS 1 6 speed Ford 9 inch Detroit Tru Track, Dakota Didgital, Vintage Air, QA1 Coil Overs Front & Rear Lots of FUN 2013 GMC PU, Oldest Son 71 GMC LWB. QA1 Suspension, Angry SB. Youngest Son 2017 Toyota SUV Daughters car 2018 Traverse , Wife’s Ride Pittsburg Ca 94565

02-09-2003, 11:16 PM	#5
GMC Jim Senior Member Join Date: Dec 2002 Location: Portland, Oregon Posts: 901	I replaced the #194 lamps with #168 lamps which are 3 CP compared to 2 CP... ( 1/3 brighter! )... leave the headlamp ho/lo indicator lamp with the original 194 lamp... __________________ '71 GMC;fleetside;PB/PS/AC/CC/402 Eng./Custom Paint/110,000act miles/3 fuel tanks(52gal).

02-05-2003, 09:16 PM	#1
KWinBigE Registered User Join Date: Jan 2003 Location: Eufaula, OK Posts: 19	dash light problem First, I just bought a 71 Custom 10 and I sure appreciate what a wealth of knowledge there is on this board. Already picked up a lot of good info. But..... Here's one I haven't seen before. The dash lights on my '71 work but are real dim. I turn the knob all the way just short of the dome light coming on and they get a little brighter but still very dim. All external lights and signals work as advertised. Here's some possible clues. Both turn indicators come on (and stay on) when I turn on the lights, but the signals and flashers still work fine. The dash lights are even dimmer when the high beams are on. The dash was replaced with a tach dash (before I got the truck). I'm thinking it might be a printed circuit board problem? Any suggestions for troubleshooting further will be appreciated. Thanks, Kim __________________ 71 Custom 10, LWB RED, RED, RED

02-06-2003, 09:56 AM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Everything that you describe indicates a ground problem. The dash gets its ground through the connector that plugs into the dash. I would suggest adding a separate ground wire and attach it to the metal back of the dash. Jim



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