Author Topic: Dash and interior lights  (Read 3550 times)

hotrod68

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Dash and interior lights
« on: June 02, 2010, 08:41:16 AM »
Hi, fellows:
  My problem is my dash and dome lights--they haven't worked since I re-installed the wiring harnesses in my '68. All the idiot lights and turn signal indicators in the instrument cluster work as they should, as do the 4-way flasher lights, marker lights, and everything else on the circuit, but I have no instrument cluster lights and no power to the heater control bulb and dome light. I have power for the dash lights at the light switch and have used this for power to my gauge lights and they illuminate with the dashboard switch. The instrument cluster is grounded, else the idiot lights and turn signal indicators would not work. I realize that there may be a break in the printed circuit on the back of the instrument cluster that is causing the dash lights not to work, but would this affect the heater control light as well? And what of the dome light? The car has a new headlight switch and I've tried the old one with which everything worked, but the results are the same: No dash or dome lights. This has really got me stumped and I can't help but think it's something simple I'm overlooking. Any ideas would be greatly appreciated. Thanks.
HotRod'68  1968 SS350 coupe undergoing frame-off resto/rod. 386/350/4.11s
Butternut Yellow    black standard interior

tmodel66

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Re: Dash and interior lights
« Reply #1 on: June 02, 2010, 12:55:23 PM »
Yes it would have control over the heater control lights. Just think when you dim your interior lights it also dims the heater control lights too.
Daniel  
'69 SS 350/4 speed  Fathom Green--POP

flyingskibiker

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Re: Dash and interior lights
« Reply #2 on: June 03, 2010, 12:21:44 AM »
The dash cluster lights and heater control lights have different wires from the same circuit running to them.  So, even if the circuit board is cut, the heater lights should still get power.  The dome light is a completely different circuit (no dimming). 

If the circuit board had a short, I would think the fuse would blow...  Did you measure the dark green wire on the light switch?  That is the "out" for the dash lights from the rheostat circuit w/in the switch.  I believe the orange wire is the input power/voltage to the courtesy lights.  The red wire is the main power.  That is my current understanding... ;-)

The gray wire going to the back of the dash cluster and heater lights is the dash light circuit.  You can measure the voltage there (back of cluster), as well.  That will tell you if you are getting power through the fuse.  Oh, did you check the fuse?  Do the dome/coutesy lights come on when you turn the light switch all the way past the stop?  Or neither the light switch nor door switch turn them on?  The courtesy and dome light wires are orange and white.

What wiring brand did you use?  I have heard of some assembly issues like wires being reversed...  And (some) people say PainFUL instead of Painless... 

tom

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Re: Dash and interior lights
« Reply #3 on: June 04, 2010, 05:07:13 PM »
Sounds a bit like a ground issue. Have you tried adding a ground connection? Even a temp connection if it fixes the problem points the way towards the correct fix.
69 X11 Z21 L14 glide
looking for a 69 export model (KPH) speed
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