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fan switch going bad

Discussion in 'The Garage' started by tx_sub, Jul 23, 2004.

  1. tx_sub

    tx_sub 1/2 ton status

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    my ac fan switch shuts off on the highest fan setting. all the lower positions work. no power is getting to the blower on the highest position. my question is, can i just replace that switch or do i have to replace the whole control assembley. i see what i might need in lmc. part no 36-0681 heater switch. is this right? please help me. anyone else have a similar problem and or solution.
    'preciate it y'all
     
  2. wraenking

    wraenking 1/2 ton status

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    i would try replacing the blower relay in the engine compartment. fixed me up right
     
  3. HarryH3

    HarryH3 1 ton status Author

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    Re: fan switch going bad *DELETED*

    Post deleted by HarryH3
     
  4. tx_sub

    tx_sub 1/2 ton status

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    thanks guys. i'll hit the parts store tomorrow
     
  5. tx_sub

    tx_sub 1/2 ton status

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    Re: fan switch going bad: FIXED IT

    the harness had a burnt connector. the purple wire going to the blower box. i replaced the relay anyways. napa 8.05 and cut off part of the harness and used a female blade connector on the single wire. now all fan settings work. it only cost 10 bucks in the end, an hour and a half and only one tool thrown across the drive.
     
  6. anthony stark

    anthony stark Registered Member

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    Re: fan switch going bad: FIXED IT

    My power wire for the HI setting burnt also. Caught the whole wiring harness on fire. I posted to see if this was a common problem, and to find a solution, but there was no response that helped. I still don't know what is causing it. After I install this new harness I'm going to check my ground connections
     
  7. muddbudd72

    muddbudd72 Registered Member

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    my 90 did the same thing (burnt wire),must be more common than i thought
     
  8. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: fan switch going bad: FIXED IT

    On GM cars 80's vintage many used a connector in the blower motor wiring. The "hi" setting wire almost always melts the connector for that pin. Same size wire going into and out of the connector, but apparently the pin in the connector just isn't large enough, or is barely large enough when new, and with a little corrosion, is enough to melt it.

    Could be same issue in trucks with the relay?
     
  9. tx_sub

    tx_sub 1/2 ton status

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    Re: fan switch going bad: FIXED IT

    the wire going from the relay to the blower motor is larger tnan the others coming from the relay. 12 or 10 ga. so i hope it can handle the voltage. come to think of it, it is the only wire going to the blower. why it worked on the lower settings is beyond me, maybe increased power leading to increased head/resistance and no worky. it was just the plastic on the connector that melted adn corroded the terminal. i'll have to wait and see if the blade type plug i replaced it with holds up. plus a new relay probably helps too.
     

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