Blower fan/relay

[Ricko1966]

A wire any wire piece of extension cord whatever wire you have laying around.

 

[HotWheelsBurban]

Ok so does anyone know which wire I can run directly to the battery to see if the blower spins. Thanks

On a square body truck, since the blower motor is under the hood, you could use a long jumper wire and go straight to the battery. That's what Dad did, back in the day.
On my OBS trucks it's under the dashboard, so I have to take it out and use jumper wires to check it. Still 5 screws and a couple of terminals, but just a bit harder to get to....

 

[Wallace6]

A wire any wire piece of extension cord whatever wire you have laying around.

No I'm asking which wire in the relay block will go directly to the blower motor. I don't really want to rip it apart if the motor spins, thanks

 

[Ricko1966]

No I'm asking which wire in the relay block will go directly to the blower motor. I don't really want to rip it apart if the motor spins, thanks

Your relay should be hot,when you close the points the blower should spin. If it doesn't them there is no power to the relay the wire from the repay to the blower is bad or the blower motor is bad. A relay is just a switch 12v in,just like a toggle switch 12v out to your accessorie. The difference between a relay and a toggle switch is you move the toggle switch position by hand,the relay does it with an electro magnet
So 1 lead of the relay is hot,one powered the blower. The other to are control( electromagnet)

 

[Wallace6]

Im

Your relay should be hot,when you close the points the blower should spin. If it doesn't them there is no power to the relay the wire from the repay to the blower is bad or the blower motor is bad.

Looking to take the relays out of the equation and the fan switch inside the cab. Just want to run a jumper wire from battery straight to the blower motor, without tearing the ac plenum apart. Thanks so much

 

[PrairieDrifter]

Im

Looking to take the relays out of the equation and the fan switch inside the cab. Just want to run a jumper wire from battery straight to the blower motor, without tearing the ac plenum apart. Thanks so much

No. Don't do that. That's a hack way to burn your truck down. Don't do it, or take it to someone that knows how to fix it.

Blower relay is bad if you don't have high speed. Resistor block is bad if you don't have any others, that is if you have power.

 

[Ricko1966]

No. Don't do that. That's a hack way to burn your truck down. Don't do it, or take it to someone that knows how to fix it.

Blower relay is bad if you don't have high speed. Resistor block is bad if you don't have any others, that is if you have power.

Blower relay could be good,but no control circuit,meaning no power and ground on control side. And a relay is just a switch you can replace a relay with a toggle switch it's not a fire hazard,but it is a hack method. And all of this is assuming he has a good blower motor.

 

[Wallace6]

No. Don't do that. That's a hack way to burn your truck down. Don't do it, or take it to someone that knows how to fix it.

Blower relay is bad if you don't have high speed. Resistor block is bad if you don't have any others, that is if you have power.

Maybe I said it wrong,I just need to test the blower motor

 

[mtbadbob]

Maybe I said it wrong,I just need to test the blower motor

You should just be able to hook up a wire directly from the battery & to the blower terminal. 12v's is 12v's. Do you have a stab tester to test the purple wire from the relay to the blower motor? The key has to be on before the relay sends the voltage to the motor. Also, pull the resistor out of the blower box & visually inspect it to make sure it's not burned through anywhere.

 

[Ricko1966]

Do you have a red wire,and an orange wire at the relay? If so red should be hot (12v +) Orange should be out to the blower. Use a fused jumper from red to orange if the blower doesn't come on check for 12v on the orange wire,at the blower ,and check the blower for ground. Still no blower than you need a new blower motor.

 

[mtbadbob]

Do you have a red wire,and an orange wire at the relay? If so red should be hot (12v +) Orange should be out to the blower. Use a fused jumper from red to orange if the blower doesn't come on check for 12v on the orange wire,at the blower ,and check the blower for ground. Still no blower than you need a new blower motor.

I believe its purple that runs from the relay to blower on the '87's

 

[Ricko1966]

I believe its purple that runs from the relay to blower on the '87's

Thank you @mtbadbob I didn't have a schematic handy. @Wallace6 the wire colors I states maybe incorrect, the principal is still the same. 12v in at relay jumper to blower power wire.

 

[Wallace6]

Do you have a red wire,and an orange wire at the relay? If so red should be hot (12v +) Orange should be out to the blower. Use a fused jumper from red to orange if the blower doesn't come on check for 12v on the orange wire,at the blower ,and check the blower for ground. Still no blower than you need a new blower motor.

I do have those colors and will try that thanks. Also my purple wire is connected to the relay but nothing else. Maybe it came unplugged I will have do some digging. This is a front and rear ac and heat burb,so there is a lot going on in that area. Thanks everyone

 

[RaisedK5]

This is the 90 diagram. Purple goes to the blower. If it's not hooked to anything that is your problem.

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[Wallace6]

Any i where the purple wire goes, I have looked at entire top,must plug in to the bottom, like I said there is a lot going on there currently. It was working well than just stopped,the purple wire is connected to nothing but the relay. Thanks