My heater has never worked correctly since I've owned the truck. It only worked on High or off. So I went to Toyota and they said it wasn't the switch but the heater relay coil. I'm not sure this is the correct term for it. But it's a unit that has 3 wire coils on the back and a 4 prong plug on the front (pictured below). Last week my heater died completely and I can't figure out where to replace this unit. I don't find anything that look even remotely like it. It may be the wrong unit. My truck as A/C and I'm not sure this is a A/C unit.



I have the Glovebox out and the key on, when I "turn the heater on" I hear the relay click, so tested the power lead that goes to the motor and I get power. It's something like .7 volts on low, 1.6 volts on medium and 12 volts on high. Does this sound normal? Would the next logical step to bo pull the fan motor and check it out. Is it as difficult to remove the fan motor as it looks?
Thanks for your help,
Grant

 

Your blower motor is bad. Just because it has power does not mean it is good. Yes it is "fun" to take out.

 

Pull the blower motor, not all that hard and have a look inside:
http://www.4crawler.com/4x4/CheapTri...ml#MotorRepair


Probably worn brushes, here's what mine looked like when my blower quit (on the left) and the new brushes I installed (on the right):

 

Wow, I'm glad My heater still works cause it was -34ºC (-29ºF) today with the wind chill... that's COLD! Anyway I hope you figure it out, take some pictures while your at it. I'd like to have the information just in case I have to do something like this in the future.

 

yep, if your getting 12v on high, its probably the motor has given out. Replace the brushes as 4crawler mentioned.

 

Thanks for all your insights. I had a bad feeling it would turn out to be the motor. I'll document it and post with results

I know cold here is nothing compared to cold else where, but freezing and or foggy mornings with no defroster are no fun.

Thanks again!

Does anyone have any idea about the coil unit it posted the pictures of? Just curious mostly.

 

That is the blower motor resistor:
- http://www.4crawler.com/4x4/CheapTri...BlowerResistor

Looks intact:


If burned out, the coils will be obviously damaged/missing.

 

since were on the subject... Anyone know why a heater doesnt get very "hot". My heater just gets warm and really doesnt heat up my small single cab that great. My friends toyota pickup gets really hot. Ive flushed my core out and the valve is opening all the way as well as the heater flap that that allows the hot air to the vents. Do i need a hotter thermostat or what. me and my friends truck both have 180 stats. my water pump is also fairly new so i dont think that is the problem either. any suggestions appreciated.

 

I think the stock t-stat is 190F, at least that is what it is in the 22RE:
http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

Might try using an infrared non-contact temperature gun on the inlet and outlet hoses of the heater. See what temp you are actually seeing there. Also, try blowing out the fan and make sure the motor is turning fast enough. My '85 heater will nearly burn your feet if you have the tamp on full high.

 

4Crawler your page list a few different part numbers for the blower motor resistor are they all different or are they the same with different costs?

 

on my way home tonight the heater was BLAZING hot... I dunno why but it felt nice haha. I did drive more tonight but ive driven longer distances and the heater barley got warm. I must a really good cooling system i guess

 

I found a recent problem on my heater that might help ya.
The heater control does 2 things.
Open/close the water valve on the firewall. Put it on HOT and make sure the lever point to the front of the truck for OPEN.

The other thing the lever does is to push the flapper to direct air over the heater core vs. around the heater core. If that cable housing is not secured to the heater box, the cable housing just moves and makes a deeper bend rather than flipping the flapper. The easiest way to see is to take out the glovebox and move the control lever. You'll see something moving.

 

Good to know! Thanks. I was kind of suspicious of something along those lines as well. Thanks leiniesred