Heater(blower) works intermittently

2003 TRD 4 Door 4x4 6 cyl blower works when it feels like it, sometimes a bump seems to cause it to come on or just reaching 70mph on the highway. or sometimes it wont work for days. I replaced the blower itself last year. could it be the switch behind the control panel?

Any feedback would be appreciated.

 

loose connection, bad wire, bad fan switch.

test it by running a wire straight to the battery and touch the fan terminal, if it works you know the fan isn't the problem, then touch it to the power supply to the fan controls, this will tell you at what point the power isn't getting to it.

 

Does your blower stop working on all speeds? If it works always on high then it's probably your blower motor resistor,which controls the fan speeds.

 

It works on all speeds so I know its not the resistor.

Do you know Keakar if the fan switch is this part...2003 TOYOTA TACOMA 3.4L V6 : Electrical-Connector : Blower Motor Connector

This part, the blower motor(already replaced last year) and a resistor are the only parts that are listed on rock auto.

Thx for the reply guys

 

x2 or a loose connector.

 

Ok Wanted to follow up guys, thank you for your input.

I took the center console panel out and removed the plug in the back of the fan switch and reconnected it and so far it seems to have fixed the problem.

The connector didn't appear to be loose but maybe it was. I'll know if it was in fact the connector over the next week and repost.

 

That could be it--dirty connection--nice find!

 

don't you hate it--replace something-and still have the same problem--then you find out it was something easy and simple!!!
Been there-done that.

 

wouldnt be the first time someone "thought" it was plugged in but the blade wasn't inside the terminal but laying against it so it touched but later started acting up as you had.

glad you got it sorted out.

and the blower motor switch and resistor is changed as one part and that is the resistor you were looking at, that's all there is to it. the way it works is for high speed the fan gets the full 12v, and for each slower speed they lower the voltage it gets by passing it through resistors so in most cases each lower speed adds another resistor so just picking numbers at random

high = 12v (created by a 12v power source)
med = 10v (created by a 12v power source plus one resistor)
low = 8v (created by a 12v power source plus 2 resistors)

sometimes they wire it a little differently but the principle is the same, this is why if you run a wire direct to the fan you quickly find out if its a bad switch or the fan since these are the only two parts

 

Well Heat is still working flawlessly to this point, thx again everyone for your professionalism and wisdom....

While I had the HVAC unit out I noticed two of the three panel lights were out so I replaced those and decided while I had the center dash console out I would also replace the bulbs out in the dash cluster as well, can't remember last time I had so much fun....not. Took two hours start to finish, hardest part was getting my hands up in there to remove the plugs for the diff lock, dimmer, etc. It is very cold out here today with 35 mile-an-hour wind gust, had to come in a couple times to warm my hands up in order to get the dexterity back. But its done and I will now be able to see my gages at night again on my 230,000 plus Tacoma. Feels good, can't imagine what it would have cost to have a dealership do it. Would not have been daring enough to tackle that project if it not had been for the write-ups that others had taken the time to do for everyone else to benefit from, like myself.

Again Thank You...

 

Ok Guys the heat is not working again. I posted a couple pics, first pic front of HVAC unit. I think if you double click it will make the pics larger. Could not figure out how to make them bigger as .JPG files





The second is the back of the unit. I went to the local Toyota dealership and they(she) didn't really seem to know what she was talking about, so I'm double checking with you guys. She said this comes as a complete unit for $176.00 bucks. I was told the fan switch second pic can be replaced without the whole unit? any help from the pros to confirm or deny this? If it cannot be replaced separately, does anyone have a suggestion where to get one cheaper?

 

I just had to replace my climate control box a month a go. My temp control wouldn't work.
Toyota sold me the white part in your picture for 170 after tax.

Now my system works perfectly.

If you where local I'd work a good deal out and let you pull parts from my old box as the fan and direction switches worked perfect.

 

That would be great if it doesn't have to be replaced as a unit. Which is my question

 

I'll have to check this out. This is my problem.

 

Slightly cheaper here, comes out to about $130 after shipping (they are in MA): http://toyotaparts.bochtoyotasouth.com/oe-toyota/5591035240

 

Wow that's a lot cheaper, thx for that info Ken.

I thought of another question..... Can the computer board on the back of the unit (seen in the pic) come right out by removing the 4 screws and be re-attached to the new one without any other things needing to be done?

 

No idea. Even the blue-LED swaps (e.g. http://www.customtacos.com/forum/15...-your-01-04-heater-ac-control-panel-pics.html) don't require taking the board out. It's possible the fan switch is soldered directly to the board, so there could be 10-12 points to desolder if you want to swap out just the switch.

 

Well I replaced the whole HVAC unit with a bran new one and the fan still does not work when turned on, same as the other one.

Could this have anything to do with a fuse? Anyone got the under the hood fuse diagram?

 

wait, I thought you said you confirmed you had power to the control but not coming out of it?

 

No! when I removed the unit to replace the light bulbs that were out it started working every time??? So I figured the connector was loose. Than it started not working again.

So what I want to know now is if there is a relay between the fan switch and motor somewhere on the wiring harness? Does anyone know ? and if so what end is it located closer to the motor or switch?