bad heater relay source of power failure?

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goat69
Posts: 12
Joined: Sat Mar 29, 2014 6:11 am

bad heater relay source of power failure?

Post by goat69 »

Hoping joatmon will see this, but I welcome any responses to my question. Would a bad heater relay (directly above the glove box) be the cause of no power to the 10amp fuse found by the steering column? I have no power (voltage) going to the 10amp fuse, car on or off, nor am I getting any power to the blower. Before I pull the relay box holding the 3 relays above the glove box, wanted to see if that's a possibility or should I be looking elsewhere for no power. Oh and yes the relay in the engine compartment is good. Thanks.
andrewclaus
Posts: 482
Joined: Tue Oct 03, 2017 6:38 pm
Location: Golden, CO

Re: bad heater relay source of power failure?

Post by andrewclaus »

Check the 40 Amp fusible link labeled HEATER in the instrument panel junction block. It's right above the fuses.
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goat69
Posts: 12
Joined: Sat Mar 29, 2014 6:11 am

Re: bad heater relay source of power failure?

Post by goat69 »

Thanks..did check it and it's good
andrewclaus
Posts: 482
Joined: Tue Oct 03, 2017 6:38 pm
Location: Golden, CO

Re: bad heater relay source of power failure?

Post by andrewclaus »

I guess the relay's next:
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goat69
Posts: 12
Joined: Sat Mar 29, 2014 6:11 am

Re: bad heater relay source of power failure?

Post by goat69 »

pulled the relay and tested it but online sources said reading should be between 50-120 ohms. Anything more or less should be discarded. I got a reading of 166 ohms so safe to assume it's bad?
andrewclaus
Posts: 482
Joined: Tue Oct 03, 2017 6:38 pm
Location: Golden, CO

Re: bad heater relay source of power failure?

Post by andrewclaus »

Best bet is to put a 12 Volt bench source to the coil and see if the relay works mechanically. Check the contacts both relaxed and energized and be sure they change state.

If your ohmmeter isn't calibrated, don't trust it reading at that level. Also, resistance of copper is temperature dependent.
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