Need electrical help, in trouble shooting my heater blower motor |
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Need electrical help, in trouble shooting my heater blower motor |
ww914 |
Mar 31 2014, 03:18 PM
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#1
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914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
I am in the process of determining why I don't have potential to my heater blower motor. I know the motor works because I hot-wired it to test it. Using the Haynes manual electrical diagram, I have traced all the wires (I think) and where they go on the relay board, the blower lever and checked the fuse on the fuse block under the dash. The diagram shows S13 as a fuse on the regulator panel. Anyone know where this fuse is located? If you look closely at the schematic it shows that connection T14/14 is north of the fuse, which tells me that the fuse must be somewhere on the relay board. Any help on this would be greatly appreciated.
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Dave_Darling |
Mar 31 2014, 05:42 PM
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#2
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914 Idiot Group: Members Posts: 14,986 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
That's one of the fuses on the relay board--the rear-most one, it looks like.
The circuit goes like this: Fan gets ground all the time on the brown wire. It gets +12V from the appropriate relay--the rear-most relay. The relay sends power from the rear fuse on the relay board to the fan when the relay is activated. The relay is "activated" by having one of its switching pins at +12V, and the other grounded. The +12V is supplied by the same circuit that powers the coil, and that is hot when the key is on. The ground is supplied by the switch under the heater lever. So, if the key is on and the switch under the heater lever is grounded, the relay should close and take any power that's coming through that fuse and send it out to the fan. The most common failure points are: - No fuse or the fuse is blown - The switch under the heater lever has failed or is not connected --DD |
Tom |
Mar 31 2014, 05:44 PM
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#3
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Advanced Member Group: Members Posts: 2,139 Joined: 21-August 05 From: Port Orchard, WA 98367 Member No.: 4,626 Region Association: None |
Warren,
The heater blower fuse is the rear fuse on the relay board. Your heater blower relay is the rear most relay on the relay board. Tom |
ww914 |
Mar 31 2014, 06:07 PM
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#4
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914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
Warren, The heater blower fuse is the rear fuse on the relay board. Your heater blower relay is the rear most relay on the relay board. Tom Thanks guys. Since I whined, I found a good schematic and found the fuses. They are both good and I still don't have 12v to the heater fan. Oh, I did change the relay just to test and I grounded the heater lever solid. So, I am still searching. Well, who needs heat, except I just spent a fortune on Tangerine headers and a heat exchanger. |
TheCabinetmaker |
Mar 31 2014, 07:34 PM
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#5
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I drive my car everyday Group: Members Posts: 8,300 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
It's called an auxiliary fan. It pushes air at idle. Once your moving at higher than idle the heat works.
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ww914 |
Mar 31 2014, 07:57 PM
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#6
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914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
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Spoke |
Mar 31 2014, 08:18 PM
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#7
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Jerry Group: Members Posts: 6,979 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
They are both good and I still don't have 12v to the heater fan. Oh, I did change the relay just to test and I grounded the heater lever solid. Did the relay energize when you grounded the heater lever? If so, how did you check it? I had a heater lever that did not ground the wire and didn't turn the fan on. Had to disassemble and clean the lever to get it to work. Did you check for 12V on both sides of the fuse? If you have 12V at the fuse, remove the relay and check for 12V at the appropriate plug pin. Follow the voltage and you will find the issue. |
cary |
Apr 1 2014, 08:30 PM
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#8
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Advanced Member Group: Members Posts: 3,900 Joined: 26-January 04 From: Sherwood Oregon Member No.: 1,608 Region Association: Pacific Northwest |
One more thing. Take the relay board out and flip it over. After 40 years the tar breaks down and the contacts push out thru the tar. Maybe you lost one leg.
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ww914 |
Apr 2 2014, 12:24 PM
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#9
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914 Convert Group: Members Posts: 435 Joined: 29-September 11 From: Central Coast, CA Member No.: 13,621 Region Association: Central California |
I am in the process of determining why I don't have potential to my heater blower motor. I know the motor works because I hot-wired it to test it. Using the Haynes manual electrical diagram, I have traced all the wires (I think) and where they go on the relay board, the blower lever and checked the fuse on the fuse block under the dash. The diagram shows S13 as a fuse on the regulator panel. Anyone know where this fuse is located? If you look closely at the schematic it shows that connection T14/14 is north of the fuse, which tells me that the fuse must be somewhere on the relay board. Any help on this would be greatly appreciated. Well guys, I would never rat on someone else, but since it is me, here goes: When I thought the problem was electrical gremlins and the problem simply could not be fixed, the magic light came on. I had the relay in the wrong hole. Geez, it works good when the 'lectric flows where its suppose to. (IMG:style_emoticons/default/idea.gif) |
TheCabinetmaker |
Apr 2 2014, 12:43 PM
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#10
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I drive my car everyday Group: Members Posts: 8,300 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
Every man makes mistakes. A bigger man admits his mistakes and learns from them.
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