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#1 |
Registered User
Join Date: Jan 2002
Location: Elizabethtown, KY, USA
Posts: 136
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Dash Light problems
I spent a while going through other threads but I'm not finding anything to help me.
The issue is I have no dash lights other than the high beam indicator light. I had them when I put the truck back together, but when I had the lights on for 5 minutes I smelled electrical smell and next time I started, the lights didn't come on and haven't since. I did a few things that could of caused it when putting truck back together. It might be the original switch I reused. It might be that I replaced the T5 bulbs in the dash with LEDs and it didn't create enough resistance so it burned up wire? Truck was apart for 2 years in a dirty shop and painter painted over the fuse block labels. All fuses check good. all other lights including tail lights work fine. Can someone tell me what color(s) wire do I need to check the circuit on the back of dash plug or if it is possible it's just a bad switch?
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My Truck: 1968 C-20 Custom Camper |
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#2 |
Registered User
Join Date: Oct 2005
Location: Overland Park, Ks.
Posts: 5,216
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Re: Dash Light problems
The dash lights use a light grey wire. There is a separate fuse for them but you say all the fuses are o-k. LED's would not burn the wires or over load the circuits but would not dim when you turned the handle. You probably have a bad reostat on the light switch.
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#3 |
Registered User
Join Date: Dec 2010
Location: sioux city, iowa
Posts: 619
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Re: Dash Light problems
It might be that I replaced the T5 bulbs in the dash with LEDs and it didn't create enough resistance so it burned up wire? (NOT)
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#4 |
Registered User
Join Date: Dec 2010
Location: freeburg, illinois
Posts: 885
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Re: Dash Light problems
could it be the circuit thing on the back? that flexible copper thing, not sure if your truck has it i just know my 85 is torn in two places and no longer lights up. Just throwing that out there
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#5 |
Registered User
Join Date: Mar 2003
Location: San Francisco, CA USA
Posts: 2,454
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Re: Dash Light problems
Good point. The printed circuit could be damaged. Check first to see if you have power at the dash light fuse.
Ray
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Live more responsibly. Eat lower on the food chain. Eat vegetarians. Last edited by raycow; 12-08-2010 at 08:45 PM. |
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#6 |
Registered User
Join Date: Jan 2010
Location: vancouver island BC
Posts: 123
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Re: Dash Light problems
hey this is the exact topic im dealing with pulled out the dash and the printed circuit had damage.Can these be bought repro? Man I hate no dash lights went in to fix the gas guage hate that also!
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65 sbfs 65lbfs 65ccsb 65BUS 68GMC and many cars from the 60s |
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#7 |
Java Mechanic
Join Date: Jun 2005
Location: Martinsburg, WV
Posts: 6,764
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Re: Dash Light problems
They are available for at least some years. They can also be fixed if they aren't too degraded.
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Keith 11 Lincoln MKT -- Momma's wagon ![]() 13 G37xS -- middle age crazy car 68 C20 Fleetside -- RIP Decorating the whole town up at a cost of $27 .... |
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#8 |
U.S. Army Green Beret Sniper
![]() Join Date: Dec 2009
Location: Enterprise Alabama
Posts: 57
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Re: Dash Light problems
Some sections of the cluster curcuit panel is wired is series and some in parallel. That means with some bulb elements out some bulb elements will work and some will not. The wiring in the circuit panel is copper protected by plastic so if you had a short or grounded out you will see that area burned.
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#9 |
God is good!
Join Date: Sep 2010
Location: Texas
Posts: 689
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Re: Dash Light problems
Replacement printed circuits are available through LMC.
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Mando "It takes a smart man to know when he's stupid." -- Barney Rubble My build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=430367 |
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#10 |
Registered User
Join Date: Jan 2011
Location: Redmond, OR
Posts: 758
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Re: Dash Light problems
Mine don't work either, and I noticed that I am missing one of the bulb holders. Will this not allow a complete circuit and make all go out, or are they paralell?
Thanks
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68 Chev C20- son has it now 83 K20 - bought from son 70 C20 - in progress |
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#11 | |
Registered User
Join Date: Aug 2010
Location: Lost Wages, NV
Posts: 201
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Re: Dash Light problems
Quote:
Classic Industries - $39.99 Year One - $95.00 LMC - $39.95 etc.etc.etc
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1968 K10/30 Frame Off Project "Overkill" My 5 year, $30,000.00 toy |
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#12 |
Registered User
Join Date: Jan 2002
Location: Elizabethtown, KY, USA
Posts: 136
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Re: Dash Light problems
So eight years later, I decided I could no longer stand the problem and decided to diagnose it properly.
Checked the resistance on rheostat on headlight switch - ok Checked fuse and replaced - ok pulled dash, inspected all copper, polished everything until all circuits could complete to ground. checked for power to dash plug with truck on and lights on. - FAIL after quite a bit more screwing around, I realized there is a short to ground (18 gauge black pin) to (20 gauge gray pin) on the plug in the back of the dash. the conclusion is there is a burned gray wire shorting to ground somewhere in wiring harness between fuse and plug. This is kind of DUH as this is what a blown fuse should have told me 8 years ago, but I'm on it now. So I guess I will search the forums to see if I can pull off the fuse box and wire a jumper from back of fuse box to the gray wire right before the plug.
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My Truck: 1968 C-20 Custom Camper |
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#13 | |
Msgt USAF Ret
![]() ![]() Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,714
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Re: Dash Light problems
Quote:
Power goes to the no. 3 pin on the seven gauge panel and to pin seven on the 3 gauge panel. It is a pink wire from the fuse panel and it powers the fuel gauge and the temperature gauge. The lights are powered separately. to say you have a short between the black and gray wire pins means nothing unless you state the resistance that you measured because you will get a reading between the two points through the light filaments. If you are reading less than 1 ohm then you have a short but if you measure around 10 ohms then you are just reading the dash lights resistance. They are wired in parallel so you should read slightly less than the resistance of one light. Take a reading on the PNL lts fuse with the cluster plug unplugged and if you get close to zero ohms on either side of the fuse holder then you have a short in the wire from the headlight switch rheostat ( green), or the wire to the cluster plug, (gray). Don't forget that you have 2 gray wires together on the cluster plug, pin 8 or pin 12 depending on the style of cluster you have. One of these gray wires is the power wire from the fuse panel and the other wire goes to feed the heater panel light, and glove box light if so equipped. This wire is a common source for a short to ground. Before you run a jumper to the cluster plug, do a short to ground check on the fuse panel lights fuse, and if you don't read a short to ground with the cluster plug unplugged then you don't need the jumper . Make sense? Don't forget the heater panel light and that you will read approximately 10 ohms through this light if the bulb is good Then you can check The cluster for short to ground between pin 7 and 8 or between 6 and 12 if a 3 gauge cluster. Try these checks and post back.
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VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative. |
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