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#1 |
Registered User
Join Date: Jan 2003
Location: Eufaula, OK
Posts: 19
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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
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71 Custom 10, LWB RED, RED, RED |
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#2 |
I am a Referee of life.
Join Date: Jun 2000
Location: Greensboro N.C.
Posts: 13,993
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With any electrical problem on these trucks the first thing the BB members are going to tell you is to "Check the Grounds" There seem to be a lot of these type problems with these trucks.I have put grounds from block to firewall,body to frame, and from the ground on the printed circuit board.This seems to have taken care of my electrical gremlins.Also, check to see that all of the bulb holders are turned the correct way.It sounds as if the dash is grounding thru another circuit rather than a ground.Happy hunting and good luck!!
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The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil" |
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#3 |
Account Suspended
Join Date: Oct 2002
Location: Olathe, KS
Posts: 2,301
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I've seen the ground strap burn through the printed circuit board and cause that exact problem. When the oil line (factory copper) is connected, the gauge cluster will ground through that. But if you have somethign else hooked up or are using plastic line, your ground is now gone. Check the grounds..........
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#4 |
huh?
![]() Join Date: May 2000
Location: Washington, Illinois
Posts: 5,692
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that's exactly what happened with my truck...I had to ground the cluster...works fine now.
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Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay |
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#5 |
Registered User
Join Date: Oct 2001
Location: Grapevine, Tx.
Posts: 2,142
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Welcome to the board
You have come to the right place for all the answers to your Chevy Truck questions. First let me give you a link to GMC Pauls great web-site. The link will take you to the tech tips section where there is a diagram of the changes to the wiring that need to be made if you are switching from idiot light dash to the more common guage dash. GMC Pauls Tips I was not sure if your original dash was the idiot light style but thought that you may want to check the wiring to see if the previous owner did the job right. Like the others said check your grounds. My 71 has symptons just exactly as you described yours but mine is the idiot light version, I have had mine out and I can tell you that the printed circuit is a real mess. Have Fun
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John Hutchison Grapevine,Texas 68 1/2 t swb 68 Mustang 69 Jaguar 71 1/2 t swb 88 Supra CompTs6m 93 Escort GT 2005 Corolla XRS |
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#6 |
Registered User
Join Date: Jan 2003
Location: Washington State
Posts: 8,834
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The ground problem would be the first to check.
Also check your positive battery cable. I was having a very similar problem. Went through alot of areas looking for possible short.......finally found the postive cable shorting out behind the exhaust manifold. As some other posts tell about removing the negative cable and placing a light in line between it and the neg post....will show a draw on the bat. Good indication of a short. I ended up taking the under hood wiring loose at the firewall to the fusebox to isolate the short under the hood and went from there to find it. Good Luck.....
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1970 Chev CST 2003 Harley Fatboy 1975 Chevrolet Step Van 1956 Chev Bel Air 1977 Blazer 2WD For Sale $3000.00 1978 Blazer 2WD For Sale $7000.00 1978 Silverado 2005 Monte Carlo |
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#7 |
Registered User
Join Date: Oct 2002
Location: West Des Moines, Ia
Posts: 3,233
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hey does your whole dash blink when you turn on your blinkers and does your highbeam indicator stay on until you turn on your highbeams, mine does and it has gotten a little better since i grounded it but it still does not work properly
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Krazy Texan My Trucks are made with Wrenches not Chop Sticks 1967 GMC 3/4 ton "Johnny Cash" 1990 v1500 suburban 1967 Ford f100 Swb 4x4 "green bean" GOD BLESS JESUS, JOHN WAYNE, AND THE ALAMO |
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#8 |
English Chevy Owner
Join Date: May 2002
Location: Shropshire, UK/ Lot, France
Posts: 1,848
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I had similar problems, check the floor mounted dimmer switch. Mine was corroded to hell and all the problems dissappeared when it was replaced. I also added an extra ground wire from a bolt on the back of the dash cluster to the dash itself, but it was the switch that cured the problems.
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Phil '67 C10 long fleet. 350/TH350, 4 bbl Carter, K&N, Dual exhaust, loads of stuff coming soon 2001 S10 Blazer Daily Driver, bone stock 4 door 4x4 with manual transmission |
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#9 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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krazy texan... does your fuel guage work? It sounds to me like someone installed a guage panel where a dummy light panel was.
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#10 |
Registered User
Join Date: Jan 2003
Location: Eufaula, OK
Posts: 19
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BlueBeard - Just put a new Positive cable.
Krazy Texan - The fuel gauge and everything else on the dash works right. Thanks for all the replies, I'll post a fix when I find it. (Goin' after the ground as recommended.) Kim
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71 Custom 10, LWB RED, RED, RED |
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#11 |
Registered User
Join Date: Aug 2002
Location: Farmers Branch, Tx
Posts: 1,009
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I have had to replace the dimmer switch and plug on both my trucks. I think it was caused by a bad ground somewhere though.
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http://www.picturetrail.com/jwill41 67 1/2 ton GMC short step side 68 1/2 ton Chevy long fleet side 72 1/2 ton Chevy Suburban 99 1/2 ton Chevy Suburban founder (and only member) of the primer/clearcoat club |
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#12 |
Senior Member
![]() Join Date: Dec 2002
Location: Portland, Oregon
Posts: 901
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and when you have solved your problem; I might suggest that the dash lamps ( #194; 2 C.P ) be replaced with #168; 3 C.P.....as they considerably brighter.....( you can control the brightness with the headlamp switch and the brightness is there if you need it /..... You might want to consider leaving the headlamp hi/lo indicator lamp with the original #194 lamp.......
Ialso rewired the lamp to the heater/air cong. control panel so that it is connected to the parking lamp circuit..... In other words; the heater/ air cond panel has a constant brightness.............
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'71 GMC;fleetside;PB/PS/AC/CC/402 Eng./Custom Paint/110,000act miles/3 fuel tanks(52gal). |
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