Blower Resistor help, blower motor speed

[car_boy_16]

I've got the blower motor resistor out and I went to radioshack to buy these resistors that you guys are telling me about: the 0.4, 0.8, and 1.5 Ohm resistors, but the only resistor they had was a .47 Ohm resistor and it was a really big rectangular ceramic resistor that probably wouldn't even fit.

So I went to a TV repair shop and the owner comes out and knows exactly what this toyota resistor pack was without me even telling him anything. I ask if he has any 0.4, 0.8, and 1.5 Ohm resistors that he can solder on in place of these coil-wound resistors. He tells me that I cant just put any resistor on there based on the Ohm value, and that I MUST know what the wattage value is. This is where I am stuck! He wants me to find out how many watts runs through this pack so that he can solder on the proper resistors in place of these broken coils that I have now in my pack.

He tells me that these coils get so hot that you can light a cigarette on them and that even the ceramic cased resistors can get that hot as well so a large one that is touching any plastics (which the large radioshack one probably would have!) may cause a fire.

So if anybody knows the wattage value of these, please do tell! I need help! Any input or advice is definately welcome!

btw, I am a poor college student, poor even for 'college student' standards, so buying a new resistor pack for ~$50-$65 is kind of out of the question, at least for now.

[Doctor J]

I am not sure that resistor values are .4, .8 and 1.5 ohms. the blower motor is about 40 to 60 watts so get 60 watt resistor.
If you do have acess to the pull your part junkyard, pull some resistors , then while there clip the biggest coils from them (cut on the brass part, not on the coil wire), then solder these coils in the place of the broken ones on your resistor . Their resistance value is about the same.
Go to www.autoshop101.com, there is a great explanation how to use the multimeter.

[89 2wd]

[89 2wd]

I see no reason why a concrete encased resistor shouldnt work. My neighbor is an electrician who rebuilds old mixing boards and other stereo equipment and he recommended the concrete resistors because they will dissipate heat better than that little dinky piece of metal. Since the resistor pack is in the air ducts, why wouldn't the moving air act to cool off the resistors?

I believe the reason the stock ones fail is because the slower moving air cannot pass by the 0.4 resistor and because it is a smaller diameter than the much larger 0.8 and 1.5, there is a small surface area to air contact.

If you really wanted to use the original type coil wire resistor, you would probably have to make it about the same size as the others.

I will update should any problems arise.

Fan speed w/0.47 resistor and pushbutton controls.

0 = off
1 = 30%
2 = 40%
3 = 70%
4 = 100% (high)

[Dave's]

Tried the 5 watt ceramic encased resistors in my '91 toy truck. Smoked after a few uses. Larger ones like 10 watt didn't fit. Went the salvage route. (Actually e-bay but I had to rebuild as the plug wasn't compatible.) Now if you had access to a supply of nichrome wire in different resistances you could probably roll your own...

[car_boy_16]

Sorry for forgetting about my own thread...

Thanks for all the help, guys. DoctorJ, I did what you said and went to a junkyard and pulled a bunch of resistors and only found one partially good resistor so I cut the coils off of them until I got the good low and medium speed resistor coils. I didn't cut from the base, though, because my cutters were weak (or maybe me...) so I cut the coil itself. Then I brought the coils to a TV/electronics repair shop and the guy took my resistor and soldered on the good junkyard coils. He said that the soldering was hard because he wanted to use a "heavy silver" solder due to the extreme heat that goes through the resistors. So he soldered them on and charged me $5 and now my heat works 100%!!

He also told me that the ceramic encased resistors have a lot of weight to them. He said that the weight matters because when the resistors get hot the metal weakens and with the car in motion and the forces that will be inflicted on the hot resistors it could cause it to sag or bend and when that happens it may or may not touch plastic nearby and if that happens it could cause a fire. But that was just his opinion on ceramic encased ressistors for this application.

[89 2wd]

It never really gets cold here in Socal, so I don't use the heater...thus subjecting the resistors to extreme heat. I only use the blower fan with the a/c on anyway. If it does start a fire, you'll for sure hear about it