heater & battery drain problem - The 1947 - Present Chevrolet & GMC Truck Message Board Network

az1970k5 · 03-02-2015, 01:26 PM

So I found the problem with my battery drain issue using the negative battery cable test method. Shows there is a short. Found out it was a short and was fixed by pulling the a/c fuse. I also found this behind the glove box. Seems the p/o jumped the heater blower. Does anyone know what connection is missing here? When the ignition is off there is no power going to this wire but when using the negative battey cable with a test light it tells me I have a short and it all comes down to this. I disconnect the jumper and the short goes away but I have no heater.

haysonj · 03-02-2015, 03:29 PM

I'm pretty sure that plugs into the two speed relay on top of the heater box

**VetteVet** · 03-02-2015, 05:14 PM

Your heater switch connector and the resistor is shown below.

You have a 14 gauge brown wire going from the fuse panel heater switch 10 amp fuse to the heater switch shown just below the ignition switch in the diagram below. It is a three speed switch, low. medium, and high.

The brown wire is the power wire to the switch and it connects to the blue wire and the yellow wire which go to the resistor for the low and medium speeds. These two wires run through the resistor coils depending on which speed is selected.

The orange wire is for the high speed fan which also runs to the resistor where it ties into the other two wires and then goes on to the fan. It does not go through the resistor coils, but the blue and yellow wires do and then they tie into the orange wire.

There is no relay in the heater circuit unless it came from the factory

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Name: Cab-2-web.jpg
Views: 116
Size: 104.5 KB

**LockDoc** · 03-02-2015, 05:24 PM

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Here is a picture of the fan speed resistor and where it is located in the top of the inside heater box.

LockDoc

haysonj · 03-02-2015, 05:26 PM

I called it a relay should have said resister It is still located on top of the heater box in my truck

**VetteVet** · 03-02-2015, 07:58 PM

Quote:

Originally Posted by haysonj

I called it a relay should have said resister It is still located on top of the heater box in my truck

I was pretty sure that's what you meant and I got interrupted when I was typing my last sentence and should have said,

There is no relay in the heater circuit unless it came from the factory with air conditioning.

az1970k5 · 03-03-2015, 02:13 PM

Thanks. I guess thats what I was missing.

03-02-2015, 01:26 PM	#1
az1970k5 Registered User Join Date: Feb 2014 Location: Tucson,Az Posts: 128	heater & battery drain problem So I found the problem with my battery drain issue using the negative battery cable test method. Shows there is a short. Found out it was a short and was fixed by pulling the a/c fuse. I also found this behind the glove box. Seems the p/o jumped the heater blower. Does anyone know what connection is missing here? When the ignition is off there is no power going to this wire but when using the negative battey cable with a test light it tells me I have a short and it all comes down to this. I disconnect the jumper and the short goes away but I have no heater. Attached Images Last edited by az1970k5; 03-02-2015 at 01:53 PM.

03-02-2015, 03:29 PM	#2
haysonj Registered User Join Date: Dec 2007 Location: Santa Maria, Ca. Posts: 1,423	Re: heater & battery drain problem I'm pretty sure that plugs into the two speed relay on top of the heater box __________________ 69 Chevy 4x4 383 Power

03-02-2015, 05:14 PM	#3
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,717	Re: heater & battery drain problem Your heater switch connector and the resistor is shown below. You have a 14 gauge brown wire going from the fuse panel heater switch 10 amp fuse to the heater switch shown just below the ignition switch in the diagram below. It is a three speed switch, low. medium, and high. The brown wire is the power wire to the switch and it connects to the blue wire and the yellow wire which go to the resistor for the low and medium speeds. These two wires run through the resistor coils depending on which speed is selected. The orange wire is for the high speed fan which also runs to the resistor where it ties into the other two wires and then goes on to the fan. It does not go through the resistor coils, but the blue and yellow wires do and then they tie into the orange wire. There is no relay in the heater circuit unless it came from the factory __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

03-02-2015, 05:24 PM	#4
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,647	Re: heater & battery drain problem - Here is a picture of the fan speed resistor and where it is located in the top of the inside heater box. LockDoc Attached Images __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 -

03-02-2015, 05:26 PM	#5
haysonj Registered User Join Date: Dec 2007 Location: Santa Maria, Ca. Posts: 1,423	Re: heater & battery drain problem I called it a relay should have said resister It is still located on top of the heater box in my truck __________________ 69 Chevy 4x4 383 Power

03-03-2015, 02:13 PM	#7
az1970k5 Registered User Join Date: Feb 2014 Location: Tucson,Az Posts: 128	Re: heater & battery drain problem Thanks. I guess thats what I was missing.



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