Need some help guys on my dads 70 98 Olds convertible. The blower for the heat/ac quit and he recently got a new blower motor and installed it but no luck. With the key in the run position, engine off, when you turn the switch all I can here is the relay or voltage regulator click at each position, but nothing at the blower motor. Could it be the switch itself? Motor have been bench tested and are both good.

 

Very likely it's your resistor pack. Just a thought - does the car have tempmatic AC?

 

The relay should only click between High and the next lowest speed. There is no other relay in this system.

Have you checked the HEATER fuse on the fuse block (top fuse on the left side)?

Have you checked for voltage at the wires that go into the resistor, as you go through the blower speeds?



But if the resistor were completely shot, he'd still have High speed.

- Eric

 

Visually the fuse looks good and I don't think it has tempmatic ac. I will upload a pic of ac/heat panel control later. I have not checked the voltage on the different speed settings.

 

An accurate test would be to place the tip of a grounded test light on each end of the fuse and verify that both ends have voltage when the circuit is on.

 

Exactly. Start with the simple things.

- Eric

 

Would you mind 'splainin to me why? Use simple words ok? I had a faulty resistor pack in my non AC car and when it went there was no fan on high speed. If you're talking about an AC car, I'm still curious to know why.

 

Well, first of all, he does have A/C. [Simple enough so far?]

For a heat-only car:



Power goes into speed switch from yellow wire to switch contact, goes out through High terminal to orange wire, and through orange wire to motor.
No resistor needed or used.


For an A/C car:



Power goes into speed switch from brown wire, goes out through High terminal to black/orange wire, through black/orange wire to High Speed Relay, energizes relay and closes contacts, making circuit from black/orange wire from battery to purple wire to blower, and running blower.
No resistor needed or used.

- Eric

 

I checked the voltage at the resistor on the firewall next to the ac/blower box and I have 10.7 volts going in and nothing coming out! This is with the key on and the blower switch in either the low or high position. I assume this is the problem? Next problem is where do I find one and what interchanges with it? Thanks again

 

The resistor is not on the firewall, it is in the top of the blower box, inside the passenger compartment, behind the glove compartment.

If you are measuring something on the firewall, it is not the right thing.

As noted above, the resistor has nothing to do with the high speed.

- Eric

 

Sorry it was the ambient sensor switch that I was checking.

 

Ahhhhh. Well, carry on. You're getting there.

Just follow the schematic I posted (your '70 doesn't have the thermal limiter or the superheat switch) and you'll figure it out.

- Eric

 

Followed the schematic and traced the fuse down, guess what it was blowed! Thanks for your help

 

You're welcome! That's what we're here for.

- Eric

 

A blown fuse by any other name = no workee.