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1950 headlight switch question


Rosiesdad

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Hi all,

My '50 Super has an electrical issue. The instruments and ignition power (6 Volt) keeps dropping out. I see there is a current limiting device on the headlight switch. Is ALL the cars electrical power supposed to run through this switch or has someone messed with the wiring????

I think I would prefer to have a separate supply line to the ignition.

TIA,

Phil

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Phil, do you have a shop manual? It has a good wiring diagram,figure 10-115, page 10-98. Also, on page 10-71, figure 10-81, shows the light switch.Terminals #1 should have a hot wire from the bat post on the regulator. The hot wire [supply wire]to ign switch comes from a terminal on this bar. THIS IS BEFORE THE CIRCUIT BREAKER.

Ben

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Phil, do you have a shop manual? It has a good wiring diagram,figure 10-115, page 10-98. Also, on page 10-71, figure 10-81, shows the light switch.Terminals #1 should have a hot wire from the bat post on the regulator. The hot wire [supply wire]to ign switch comes from a terminal on this bar. THIS IS BEFORE THE CIRCUIT BREAKER.

Ben

I took the headlight switch out today. The wire to the instruments attaches to the input 6V lead there. It does not pass through the light switch. I measured the input voltage at 6.2V

When I connect the instrument lead the voltage drops to 5.1V with a 20.mA current draw. My first thought is that my battery has very little capacity if such a small current drops it a full volt. I continued to mess around with it and the voltage completely disappeared! Then it came back at 3.2V! I moved the wires around some more and it jumped back up to 6V. Looks like the problem is not in the switch after all. I have had the motor and instruments cut out but restored operation by cycling the light switch a couple times. I have no idea why the voltage comes and goes. Is this a voltage regulator issue maybe?

Thanks,

Phil

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Yes. I do have a manual. The problem appears to be that voltage is not reliably getting to the junction on the rear of the lighting switch. Sometimes I measure 6V sometimes 3.2V. When I removed the light switch and found the voltage still variable I eliminated the switch as a voltage pull down problem. I will clean the switch today and reinstall it since the "Direct replacement" one I ordered is not remotely similar.

I have noticed that honking the horn sometimes works sometimes not. I don't know but suspect the problem is "Upstream' somewhere. I will wait until the voltage supply problem reappears and go directly to the regulator to check it there. I have never had a regulator intermittently fail so I am not sure I am on the right track yet.

Phil

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I have no idea if this has any bearing on your situation, but after looking at the wiring diagram, would it make a difference if the two smaller wires on the starter got inadvertently switched? Just shooting blind other than following your gut feeling to clean the switch.

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Guest NikeAjax

Phil, just wondering here, um, are these new or old wires? The reason I ask is, if they are as old as the rest of the car, you may be getting resistance within the wire itself: verdigris, that icky green stuff that makes bronze-sculptures look nice, makes a jimdandy resistor too!

Just wondering,

Jaybird

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LOL. They are all OLD wires. I probably should have replaced the harness when the interior and dash was out. I didnt have any problems with it before we got rear-ended so I didn't expect all this to come up. When I cleaned the headlight switch I tightened up all the power wire junctions on the end and this may help. I appear to be getting better voltage at the dash area and to the fuel pump. I solved the problem with the horns though! I found the hot terminals on the horns were rubbing the underside of the hood. I guess there is not much clearance under there. Thus when I tried to honk the car would die!

Regards,

Phil

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I have no idea if this has any bearing on your situation, but after looking at the wiring diagram, would it make a difference if the two smaller wires on the starter got inadvertently switched? Just shooting blind other than following your gut feeling to clean the switch.

I think the Starter circuit is OK. I did find the horns hot wire grounding to the hood though! Will go through and clean all the main grounds.

p

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