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High speed only on heater fan
Posted: Fri Dec 10, 2010 7:27 pm
by kennyz
1994 SE without Climate Control. I only have high on the blower fan. I`m thinking it`s the relay. Where is it located and does anyone have a part number? TIA
Re: High speed only on heater fan
Posted: Fri Dec 10, 2010 7:39 pm
by 01bonneSC
Blower motor resistor, IMO.
Re: High speed only on heater fan
Posted: Fri Dec 10, 2010 8:01 pm
by 94SilverSSEi
01bonneSC wrote:Blower motor resistor, IMO.
x2. It's a cheap and easy fix.
Re: High speed only on heater fan
Posted: Fri Dec 10, 2010 8:10 pm
by kennyz
Where is the blower motor resistor located?
Re: High speed only on heater fan
Posted: Fri Dec 10, 2010 11:17 pm
by imidazol97
kennyz wrote:Where is the blower motor resistor located?
Here's the location of the
resistor unit. It sticks down into the airflow channel to keep it cool. If it's not got a broken
resistor link, you might have a relay problem. There's a relay that switches off the
resistor and allows the direct power relay to supply power. I always have to study the circuit diagram to figure out how the two relays work, but if your
resistor is not the problem, there is a single pole double throw relay and a single pole single throw relay involved.
The relay center can be raised a little after removing two screws to give access to the
resistor location at the end of the
blower motor wires.
Good luck.
Re: High speed only on heater fan
Posted: Sun Dec 12, 2010 1:05 pm
by John Deere Boy
These pics are for the climate control version, but i'm pretty sure yours will be in the same place. You just have a
resistor pack instead of the
blower control module.
http://www.pontiacbonnevilleclub.com/fo ... =57&t=2431
Re: High speed only on heater fan
Posted: Sat Nov 03, 2012 2:14 pm
by bonnie_99
Same situation. Only high speed fan. I pulled my resistor and it looks good. Don't know exact numbers but I have resistance on all coils. At my relay center I am not sure which one is for the blower motor. I do not have climate control. I only seem to have resistor for High speed blower. Got a better diagram? Is it possible resistor is bad despite resistance on all coils? None of them seem to be broken. Looking at relay pack going from passenger side to drivers side.............
1-a/c comp 2-horn 3-High speed blower 4 and 5-blank 6-abs pump 7- high cooling fan 8-blank. Any suggestions
Re: High speed only on heater fan
Posted: Sat Nov 03, 2012 5:58 pm
by imidazol97
bonnie_99 wrote: At my relay center I am not sure which one is for the blower motor. I do not have climate control.
The
blower motor relay is the 4th from the left facing the car in the diagram I posted previously.
The 3rd one is the high speed relay which is a double pole single throw relay. It is in circuit with the
blower motor relay normally and allows power to the
resistor pack to modulate the speeds.
Then when the selector switch is on HI, it throws and contacts the high speed line directly through the 30 amp fuse in the relay center.
You can take out the relay and trouble shoot it for continuity in relaxed position which is your low speeds. I suspect burned contacts inside. The cover can be taken off. There is no equivalent relay in the group on the firewall to switch with. The others are all single pole, single throw and can be switched for troubleshooting.
bonnie_99 wrote: Is it possible resistor is bad despite resistance on all coils? None of them seem to be broken. Looking at relay pack going from passenger side to drivers side.............
1-a/c comp 2-horn 3-High speed blower 4 and 5-blank 6-abs pump 7- high cooling fan 8-blank. Any suggestions
Re: High speed only on heater fan
Posted: Sat Nov 03, 2012 6:08 pm
by bonnie_99
I do not have the 4th from the left(blower motor relay). So are you telling me you suspect burned contacts in the 3rd one from left (High speed relay)?
Is this one responsible for both low and high speed on the fan?
Re: High speed only on heater fan
Posted: Sat Nov 03, 2012 7:01 pm
by imidazol97
bonnie_99 wrote:I do not have the 4th from the left(blower motor relay). So are you telling me you suspect burned contacts in the 3rd one from left (High speed relay)?
Is this one responsible for both low and high speed on the fan?
This is confusing from my FSM. The Buick has both relays. Sorry. Yours is a Pontiac. It has one relay that switches between the speed line from the
resistor pack and the 30 Amp direct line from the underhood fuse.
The relay has 5 lines
It is called the
Blower relay but does the switching with the high speed circuit on your car.
The orange and black lines are low power for the solenoid that moves the contact.
The Dark Blue is the line from the
blower motor resistor.
The Red is from the 30 amp fuse
The purple goes to the
blower motor.
If you use a fused jumper, 20 or 25 amp, between the dark blue and the purple lines when you remove the solenoid, with the key ON you should be able to change the fan speeds for the 3 low speeds. That bypasses the relay.
With key ON you should have voltage from the dark blue line to ground if your circuits through the resistors are good.
The relay should have continuity (0 ohms resistance) between the terminals for the dark blue and the purple lines.
http://www.rockauto.com/catalog/moreinf ... cc=1357062
This relay is under rockauto.com 1999 pontiac bonneville
electrical-switch and relay
heater
blower relay
10$ to $23