Hvac blower motor resistor help!!

I never made much money at it either.

 

Damn that made me laugh!

 

You' re a mess...

 

I dunno, I have a dollar bill...

 

Don't worry I dropped a 100lb dumb bell on my chin back in the day. Shit happens.

 

Sorry to interrupt the fun, but the blower motor should always have Voltage at the motor black wire with a yellow strip when the truck is on and the fuses IG1 No2 10 amp and the Heater 50 amp are not blown. See the attached circuit schematic. Toyota turns the blower off and controls the speed using the ground circuit and resistor pack.

Just having 12 volts at the motor only tells you that the fuses are good, the wire isn't broken and the heater relay is on.

 

Let's get on with it then.

 

That's why I never made much money at it.

 

Thanks for chiming in Jimmy

Thats all good info to have, checking for power at that black/yellow wire would tell you if one half of the circuit is good.

How do you suggest using the multi- meter to check the ground/control side? Voltage drops across the resistor? Ohms/resistance tests? Both?

Throw up a schematic of the control side and we can walk her through it

 

Here it is:
* I usually would use a resistance check across the resistors, but in this case I do not know what their values should be.

My bets would be on the connectors ( male & female ) at the resistor pack itself and the actual 2 wire connectors on the motor itself. Both have been known to burn. If the motor connector no speeds work or are intermittent.

 

Okay Jenn..

Step 1- look at the connectors and make sure they aren't burned

Step 2- with everything plugged in and turned on check for battery voltage here (motor connector) at black/yellow


Step 3- disconnect the motor connector again, set the multimeter to measure ohms, put one lead at a good ground (battery negative, frame) and the other lead at white/light blue

Even with the ignition key off you should get continuity through here right Jimmy? You could move the fan speed switch through different positions and (even though we dont know the exact value) the reading should change. I'm gonna go out on a limb and say any reading under 100 ohms is acceptable? If you see OL (out of limit) or a super high number on the meter then you've still got a broken wire and you have to keep looking.

But.... if you've got a reasonable resistance number on the resistor side (white/light blue) and battery voltage on the power side (black/yellow) then the fan motor should run. If it doesn't, it needs a fan motor.

Sorry for the tech babble Jenn!

If you're up to it, we can help you along. This is pretty much what they'd be doing at a shop if you took it there..

 

Yes, key off and the 2 wire connector loose from the blower motor. White wire with a Blue Stripe should read continuity depending on the speed will determine the resistance to a good ground Frame Negative battery...

High speed should be nearly a dead short circuit.
Medium 2 (M2) should read a bit higher resistance than high speed.
Medium 1 (M1) should read a bit higher resistance than M2 speed.
Low Speed should read the most resistance.

And as stated by b_r_o if you see OL or a reading in the meg ohm scale you have an open circuit, broken wire etc.

Also note that the resistor pack on the schematic shows a fuse integrated into the circuit board. See the squiggly line ~ on resistor pack Hi terminal where the incoming white w/blue stripe wire goes to the resistor pack. That would be an internal fuse.

You can unplug the resistor 4 wire connector and read the pins on the pack to check this fuse. Read from terminal 2 on the pack to any of the other three and it should show some resistance value. If it reads OL you have a defective resistor pack.

I hope this is clear enough for you Jenn.

 

This is all making my head hurt right now but it's been a rough week... I'll try to read through it all when I get home from work.

 

Safe to use on the connector wires right?


Name of these is just awesome....

 

Yes....but the yellows are for a large gauge wire. The blue would suit you better

 

I do love me some Butt Splice.

Yes they work fine, but go with the blue 16 - 14 gauge.

And get a proper crimp tool for insulated butt splices.

 

shhh! she's looking for sliders now.

 

I'm so confused right now