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Old 01-04-2009, 01:28 PM   #1
Eyegore
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Electrical woes

OK guys I need your help on my 78 c20.
First problem, dash lights don't work, everything else does in the dash does, gauges -oil, temp., gas, wipers, headlights. But at night no dash lights when headlights are on. All fuses are good.

Second problem. I just redid the horn cap with pin, cup, etc. all inside the steering wheel. Now when I hit the turn signal to go right the horn honks on and off as the signal goes on and off, it does not do this on left directional. However when I pull the emergency flashers on, there is no flashing just a clicking down under the dash in the signal relay box, this is with the key in on and off position. Again all of this started after I changed the missing horn mechanism. Where did I screw up?

P.S. lights were not working long before the horn issue.

Thanks

Tom
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Old 01-04-2009, 01:37 PM   #2
us111
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Re: Electrical woes

hello,dash lights could b the ground.on mine there is a black wire
from back of gauge cluster then attaches kinda up above the
e brake pedal.also could b the part of the headlight switch that
rotates to dim the dash lights.
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Old 01-04-2009, 04:21 PM   #3
Eyegore
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Re: Electrical woes

Quote:
Originally Posted by us111 View Post
hello,dash lights could b the ground.on mine there is a black wire
from back of gauge cluster then attaches kinda up above the
e brake pedal.also could b the part of the headlight switch that
rotates to dim the dash lights.
I checked the switch, it appears good, but its electrical - I hate electrical issues
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Old 01-04-2009, 04:55 PM   #4
87Bob
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Re: Electrical woes

Quote:
Originally Posted by us111 View Post
hello,dash lights could b the ground.on mine there is a black wire
from back of gauge cluster then attaches kinda up above the
e brake pedal.also could b the part of the headlight switch that
rotates to dim the dash lights.

I agree I had the some of the same problems when I got my 85 with the ground. I had a lot of weird gremlins that disapeared when I re-grounded the the cluster. I was getting back feeding thru my turn signals when i'd hit the brakes with the dash light on.
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Old 01-04-2009, 05:09 PM   #5
87Bob
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Re: Electrical woes

Quote:
Originally Posted by Eyegore View Post
OK guys I need your help on my 78 c20.
First problem, dash lights don't work, everything else does in the dash does, gauges -oil, temp., gas, wipers, headlights. But at night no dash lights when headlights are on. All fuses are good.

Second problem. I just redid the horn cap with pin, cup, etc. all inside the steering wheel. Now when I hit the turn signal to go right the horn honks on and off as the signal goes on and off, it does not do this on left directional. However when I pull the emergency flashers on, there is no flashing just a clicking down under the dash in the signal relay box, this is with the key in on and off position. Again all of this started after I changed the missing horn mechanism. Where did I screw up?

P.S. lights were not working long before the horn issue.

Thanks

Tom
I noticed you said you replaced the missing horn mechanism. That may be the reason why it was missing in the first place. I would back up and remove the items that you installed. and check out each circut ( the horn and the turn signals). What you may find is that someone many have taped into one to power the other. FIRST remove the parts you installed on the horn then fix your ground problem on your gage cluster. Then trouble shoot the horn circut. Then the turn signals. While your knocking around under the dash look for chaffed wires around the exit point on the steering column it could just be that the wires have been chaffed and are grounding on the cloumn. The horn circut like the dome light operates when a ground is introduced. In other words there is power in the wire comming up the column when you press the button you ground the circut allowing power to flow just like when you open a door you ground the circut allowing the power to flow thru the light to ground thru the door switch. Good luck let us know what you find.
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Old 01-04-2009, 05:20 PM   #6
Eyegore
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Re: Electrical woes

Quote:
Originally Posted by 87Bob View Post
I noticed you said you replaced the missing horn mechanism. That may be the reason why it was missing in the first place. I would back up and remove the items that you installed. and check out each circut ( the horn and the turn signals). What you may find is that someone many have taped into one to power the other. FIRST remove the parts you installed on the horn then fix your ground problem on your gage cluster. Then trouble shoot the horn circut. Then the turn signals. While your knocking around under the dash look for chaffed wires around the exit point on the steering column it could just be that the wires have been chaffed and are grounding on the cloumn. The horn circut like the dome light operates when a ground is introduced. In other words there is power in the wire comming up the column when you press the button you ground the circut allowing power to flow just like when you open a door you ground the circut allowing the power to flow thru the light to ground thru the door switch. Good luck let us know what you find.
I believe my gremlins started when my son took the dash and steering apart. The horn and dash lights worked fine but they lost the steering horn parts and I found replacements at the wrecking yard.
My concern now is a condesor I removed on the blower motor a while back. I know the blower is activated by power and that condesor may have been in there for a reason.

Tom
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Old 01-04-2009, 09:32 PM   #7
87Bob
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Re: Electrical woes

Quote:
Originally Posted by Eyegore View Post
I believe my gremlins started when my son took the dash and steering apart. The horn and dash lights worked fine but they lost the steering horn parts and I found replacements at the wrecking yard.
My concern now is a condesor I removed on the blower motor a while back. I know the blower is activated by power and that condesor may have been in there for a reason.

Tom
Probably to reduce radio noise. They used them for noise supression in various places. As I remember they had them on alternators at one point in time.
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