Quick Wiring Question- Heater and Lighter

Discussion in '1947-1954' started by Haasman, Oct 10, 2019 at 12:11 AM.

  1. Haasman

    Haasman Member

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    I am wiring my '51 3100 with a simple OEM style harness. Where should I connect the heater blower motor and lighter? It seems everything routes through the headlight switch. Wondering if there isn't a better way? Thinking of eventually adding a radio. All three could run off the same 12v source?

    Any suggestions/comments?

    Thanks in advance.

    Haasman
     
  2. Bill Hanlon

    Bill Hanlon Member

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    The heater fan motor could take a lot of current and I prefer to not have that current going through the ignition switch. If you are using an OEM style harness I assume that you are using a stock 3 terminal ignition switch and ammeter and would prefer it to measure the complete electrical system including the heater and lighter socket. If so, I'd wire it like this.

    Get a 30 amp self resetting breaker like this: CURT 30-Amp Universal Circuit Breaker-58361 - The Home Depot and a 40 amp Bosch style relay like this: Pico Relay and Connector Kits 5591PT
    Make sure it comes with a socket/pigtail.

    Using 12 gauge wire, connect either terminal of the circuit breaker to the terminal on the ammeter that does NOT connect to the battery. Keep this wire as short as you are comfortable with, considering where you will mount the circuit breaker.

    Connect two wires to the other side of the circuit breaker. One wire will go to the lighter socket, the other to pin 30 of the relay.

    Connect a wire from pin 85 on the relay to ground.

    Connect a wire from pin 87 on the relay to the heater switch.

    Connect a wire from pin 86 on the relay to the accessory lug on the ignition switch. Use the ignition lug if it is easier to work with.

    Red below is existing, while black is the new stuff. When you add the radio you could power it from the same wire as pin 87 on the relay.

    [​IMG]
     
    Last edited: Oct 10, 2019 at 9:31 PM
  3. Haasman

    Haasman Member

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    Thank you Bill! Really appreciate you taking the time to post this.

    Haasman
     
  4. Bill Hanlon

    Bill Hanlon Member

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    By the way, if you add a radio with memory connect the memory power wire where the lighter connects.
     
  5. Haasman

    Haasman Member

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    Good reminder! Thanks again Bill.
     

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