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Old Oct 17, 2014 | 04:44 PM
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Hi Beam indicator

Hey all,

My hi beam indicator on the dash wont turn off. If I unplug the headlight (we only have 1 hooked up right now) it will go out when the switch is on low beam but as soon as I plug the headlight back in, the in dash indicator shows high beam, even if its actually in low beam. Any ideas?
 
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Old Oct 17, 2014 | 05:19 PM
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check the ground for that headlight connector...using a voltmeter you should have very low resistance from the black wire to bare metal on the body...
 
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Old Oct 17, 2014 | 05:31 PM
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should both wires to the light (red/blk low beam, grn blk high beam) be hot when the high beams are on?
 
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Old Oct 17, 2014 | 05:47 PM
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I assume you are talking voltage and not temperature...are you seeing voltage on both wires with the headlight unplugged or plugged in? If you have a bad ground and the headlight is plugged in, yes you will see voltage on both.
 
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Old Oct 17, 2014 | 05:49 PM
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If you have Java installed, the following simulation will show what happens when a ground opens...the Hi/Lo beam switch is clickable and there is a momentary switch to simulate a bad ground...with the Hi/lo in the lo beam position click the momentary switch and notice what happens to the current flow...

Circuit Simulation
 
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Old Oct 17, 2014 | 06:23 PM
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Unplugged both red and green wires have power when on high beam. If the light is unplugged, then only the red wire has power. I cleaned the ground connection that bolts just above the headlight - still doing the same. Are there other grounds?
 
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Old Oct 17, 2014 | 06:45 PM
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now you are confusing me..."Unplugged both red and green wires have power" and "If the light is unplugged, then only the red wire has power"...which of these statements is true? I'm going to assume you meant when plugged in both red and green have power...that either indicates a bad ground, OR a bad headlight (internally shorted filaments). You didn't indicate if the headlight visibly switches between low and high beam when you change the switch...

also, did you perform the first test I mentioned? check continuity from the headlight plug black wire to bare metal on the body?
 
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Old Oct 17, 2014 | 08:09 PM
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I'm confusing myself!
Let me try again. With the headlight hooked uo\p, we have power to both wires. Whether or not the headlight is on hi or low beam the indicator in the dash says hi beam (yes, the headlight hi and low beam work).

When we disconnect the headlight, only the red wire has power (on low beam) and the he beam dash indicator is out, like it should be. Going to study your diagram more once my java updates....
 
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Old Oct 17, 2014 | 08:21 PM
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We've also noticed that the headlight itself, when disconnected, will complete a circuit when I touch my test leads on 2 of the three prongs (not the ground prong) Could that be the problem?
 
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Old Oct 17, 2014 | 08:46 PM
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Well, I feel a bit like a ******* but we fixed it. the whole time we were doing this the gauge cluster was out. With power going up from the switch to the cluster when the lights were on high or low beam, we ASSUMED that the light would still be on, However after testing voltage, we noted that w/the high beams on, it was sending 12 to the cluster, w/the low beams on, only 9 volts. Turns out that 9 volts is not enough to power the light in the cluster - once we hooked the cluster up we discovered this. A night of jacking around but I learned something...

DLBurch, thanks for your assistance!
Thanks for your assistance
 
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