High speed only on heater fan

[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

[01bonneSC]

Blower motor resistor, IMO.

[94SilverSSEi]

Blower motor resistor, IMO.

x2. It's a cheap and easy fix.

[kennyz]

Where is the blower motor resistor located?

[imidazol97]

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.

[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

[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

[imidazol97]

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.

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

[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?

[imidazol97]

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