light switch/gauge question

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Cav Trooper
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light switch/gauge question

Post by Cav Trooper »

I don't know if I have a problem or not. Here is my issue...with the light switch in the all off position, my instruments don't register, ie; fuel, oil, temp, when I turn the light switch to the first position for brake lights, etc. the gauges still don't register but, when I turn the switch to the second position to turn on the running lights/headlights etc. the gauges work. Do I have a wiring cross up? I can't find anything in the manuals, maybe not looking in the right place, that describes the gauge functions relative to switch positions.

Thanks,

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Re: light switch/gauge question

Post by achiem37 »

Th epower supply to the gauges comes from the ignition main switch. With it on the gauges have power from wire # 27 that feeds the 4 or 5 wire spider assembly to the gauges. Sounds like someone has crossed up the wiring to fix a problem?? Wire t# 15 supplies the light switch at it's connector and it's fed from the circuit breakers before it via wire # 11 and wire # 10 that comes out of the regulator harness . The ignition switch gets it power from this wire # 11 at the lighting circiut breaker via a double connector. This way the lights have constant "on" power from the battery. Terry
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Re: light switch/gauge question

Post by Cav Trooper »

Thanks.

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HHT 2nd ACR
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
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1969
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Re: light switch/gauge question

Post by cuz »

I would first make sure the spider wire set #27 is connected directly to the main (ignition) switch. Once you have insured this and you then find the light switch does not work without the main switch being on you can then sort out that wiring mixup and make sure the light switch wire #15 gets it's power from the circuit breaker.

You may find almost any number of terminals on your ignition switch which are often changed over the years. Just apply the M37 or M37B1 diagrams below and do what is necessary if your switch wire count is different.
M37 closeup wires sm.JPG
M37 closeup wires sm.JPG (142.35 KiB) Viewed 558 times
M37B1 closeup wires sm.JPG
M37B1 closeup wires sm.JPG (149.04 KiB) Viewed 558 times
Wes K
wsknettl@centurytel.net

54 M37, 66 M101, 45MB, 51 M38, 60 CJ5, 46 T3-C
MVPA 22099

Disclaimer: Any data posted is for general info only and may not be M37 specific or meet with the approval of some esteemed gurus.
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