Heater Control Blower Switch Wiring Help Please
Thread Starter
Instructor
Joined: Oct 2011
Posts: 153
Likes: 0
From: Des moines Iowa
Heater Control Blower Switch Wiring Help Please
Replaced the Hi blow relay with a new on from willcox. tested the resistor and its fine. When everything is hooked up correctly the Hi blow relay just buzzes. If I jump orange and black wires that go to relay I have high speed from the switch to the blower motor. It works
though even with the key off. I tested all the wires and there isn't one wire that is hot with key on and dead with key off. What do I have to do to fix this?
though even with the key off. I tested all the wires and there isn't one wire that is hot with key on and dead with key off. What do I have to do to fix this?
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
That's a tuff one to give info on. I guess the first move is check to see it the hot wire is hot and the ground wire is grounded well going to the relay. On corvettes, it always seems to be the ground that causes the biggest headache.
Thread Starter
Instructor
Joined: Oct 2011
Posts: 153
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From: Des moines Iowa
I have 3 hot wires if I remember right. the black wire must be shorted because if I ground it it sparks. if I hook it up the way it was originally
the relay buzzes but nothing works.
Thread Starter
Instructor
Joined: Oct 2011
Posts: 153
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From: Des moines Iowa
should I run a ground from the black wire on the relay?
Thread Starter
Instructor
Joined: Oct 2011
Posts: 153
Likes: 0
From: Des moines Iowa
Thread Starter
Instructor
Joined: Oct 2011
Posts: 153
Likes: 0
From: Des moines Iowa
it tested out fine continuity where it should have.
it still only works on high speed. if you turn the selector to off it cuts
the power to the switch. but if selector is in any other position the blower motor stays on even with ignition key off. Is this the way it is supposed to be? anyone else have an idea what could be wrong?
Im thinking the new relay must be defective or I have a cut or frayed wire somewhere or corroded connection somewhere.
Instructor
Joined: Feb 2015
Posts: 194
Likes: 11
From: Tennessee
Closely check the plug to the relay. I found mine to have a hot spot with melted plastic allowing a couple of the wires in the three wire plug to short. I pulled the wires and connected separately and solved my problem.
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Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Blower Switch Testing 77-82
You said if you jump orange to black... orange is the hot high blower power wire and if you connect it to the black ground it should short out.... Power input to the blower motor is on the purple wire... Are you sure the car is wired correctly?
It sounds to me like you have a wire issue... what was the car doing before you replaced the high blower relay?
Below is a schematic that should help you isolate the issue.
When everything is hooked up correctly the Hi blow relay just buzzes. If I jump orange and black wires that go to relay I have high speed from the switch to the blower motor. It works
though even with the key off. I tested all the wires and there isn't one wire that is hot with key on and dead with key off. What do I have to do to fix this?
though even with the key off. I tested all the wires and there isn't one wire that is hot with key on and dead with key off. What do I have to do to fix this?
It sounds to me like you have a wire issue... what was the car doing before you replaced the high blower relay?
Below is a schematic that should help you isolate the issue.
Last edited by Willcox Corvette; Apr 21, 2015 at 11:46 PM.
Thread Starter
Instructor
Joined: Oct 2011
Posts: 153
Likes: 0
From: Des moines Iowa
Blower Switch Testing 77-82
You said if you jump orange to black... orange is the hot high blower power wire and if you connect it to the black ground it should short out.... Power input to the blower motor is on the purple wire... Are you sure the car is wired correctly?
It sounds to me like you have a wire issue... what was the car doing before you replaced the high blower relay?
Below is a schematic that should help you isolate the issue.
You said if you jump orange to black... orange is the hot high blower power wire and if you connect it to the black ground it should short out.... Power input to the blower motor is on the purple wire... Are you sure the car is wired correctly?
It sounds to me like you have a wire issue... what was the car doing before you replaced the high blower relay?
Below is a schematic that should help you isolate the issue.
work at all. I ran a new ground wire from the blower motor. if all hooked up as original or according to schematic relay buzzes or blower motor doesn't come on at all. If I ground original black wire not the one from relay plug it does short out. I guess will have to keep testing and troubleshooting. should yellow power input wire to switch be hot even with key off?
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,851
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Jumping orange to black makes no sense at all. The black is the ground and the orange is the power to the relay when the motor is in high blow. The orange wire should have power when you have the blower in high.
When in lower speeds the blower is controlled by the power input from the dark blue.
The function of the blower relay is to switch the blower motor power from the the resistance dark blue circuit to the orange wire circuit.
When you place the blower switch in high position power from the yellow goes to the orange and when the orange wire gets power it energizes the relay and the voltage side is switched to red.
You can bench test the relay by following the info posted below.
When in lower speeds the blower is controlled by the power input from the dark blue.
The function of the blower relay is to switch the blower motor power from the the resistance dark blue circuit to the orange wire circuit.
When you place the blower switch in high position power from the yellow goes to the orange and when the orange wire gets power it energizes the relay and the voltage side is switched to red.
You can bench test the relay by following the info posted below.
Thread Starter
Instructor
Joined: Oct 2011
Posts: 153
Likes: 0
From: Des moines Iowa
Jumping orange to black makes no sense at all. The black is the ground and the orange is the power to the relay when the motor is in high blow. The orange wire should have power when you have the blower in high.
When in lower speeds the blower is controlled by the power input from the dark blue.
The function of the blower relay is to switch the blower motor power from the the resistance dark blue circuit to the orange wire circuit.
When you place the blower switch in high position power from the yellow goes to the orange and when the orange wire gets power it energizes the relay and the voltage side is switched to red.
You can bench test the relay by following the info posted below.
When in lower speeds the blower is controlled by the power input from the dark blue.
The function of the blower relay is to switch the blower motor power from the the resistance dark blue circuit to the orange wire circuit.
When you place the blower switch in high position power from the yellow goes to the orange and when the orange wire gets power it energizes the relay and the voltage side is switched to red.
You can bench test the relay by following the info posted below.
Pro
Joined: Nov 2013
Posts: 730
Likes: 37
From: Catoosa Okla
Replaced the Hi blow relay with a new on from willcox. tested the resistor and its fine. When everything is hooked up correctly the Hi blow relay just buzzes. If I jump orange and black wires that go to relay I have high speed from the switch to the blower motor. It works
though even with the key off. I tested all the wires and there isn't one wire that is hot with key on and dead with key off. What do I have to do to fix this?
though even with the key off. I tested all the wires and there isn't one wire that is hot with key on and dead with key off. What do I have to do to fix this?
Thread Starter
Instructor
Joined: Oct 2011
Posts: 153
Likes: 0
From: Des moines Iowa
Huh? Sounds like a dead short if these two came together unless a PO did a rewire. Willcox came to the rescue again with a great schematic that can be used to undoubtedly correct the issue. Keep in mind all the high blower relay does is switch a N/O contact and allow the blower motor to draw current, not through the console mounted switch and rheostat circuit , but through the relay and it's powered through an orange wire going through a barrel fuse running off of a fenderwell mounted power source over on the alternator side. The switch on the console (in high speed) energizes the the coil only on the relay (switches the NO contact to a NC) With the Willcox schematic you can see the coil terminals vs the ones that carry the high speed fan load. Good luck!
