2011 4runner SR5 HVAC Blower Relay Issues

Hi All - I am new to this forum and to 4runner ownership - TIA for your help. Just bought this rig (188K miles) a couple of months ago and it just developed a couple of problems. One - the in cabin blower (manual system) will turn on/turn off by itself/ turn on again... It is even turning on when the truck is not running - KOIO. I suspect it is the blower relay sticking/malfunctioning so I am changing out the blower (cheap insurance) and need to change out the blower relay but cannot find it? Can anybody point me in the right direction? Also at the same time the alternator has failed. I checked the Alt fuse and it looks good - battery terminal voltage at 12.3 and declining when running (fully charged battery) - could this just be a coincidence? Thanks again!!

 

Might be a coincidence, but weird things can happen without proper power being supplied. Before you throw the parts cannon at it, fix what you know is bad and that is the alternator. I wouldn't cheap out either. Go OEM (which is Denso). The original gave an amazing 188K, and there's no reason it shouldn't go another 188K. Buy once, cry once.

 

Thanks Cat and I agree. Have already picked up the alternator. Any thoughts on the location for the blower relay?

 

Should be in the engine compartment on the driver side. I don't have time now, but I'll look in mine and I've also got a FSM I'll check.

 

So it's turning on when key is out of the ignition? Any other electrical issue with this vehicle?

 

Thanks cat for help chasing this... Yep - turning on when the car is off....sometimes the blower will stop running without touching the fan speed control knob. The only other electrical issue is the alternator is not charging....everything else is ok...

 

There are 3 relays related to to heater/blower, and they are located in the engine compartment. This is what I found.

 

Thanks cat - I appreciate your help! I checked - my truck only has No 1. The relay tested good when pulled to bench test and when in operation. Further - when I pulled this relay and turned the fan switch to on, it still ran... Looks like these relays control a small resistance heater(s) - not the blower....the search continues.

 

May not be related but something to look at-https://www.tacomaworld.com/threads/turn-truck-off-take-key-out-blower-runs-lights-on-dash-stay-on.778773/
https://www.toyotanation.com/threads/blower-motor-run-when-off.928465/
https://www.tundratalk.net/threads/2011-tundra-vent-fan-runs-even-when-truck-is-off.557785/

Resistor is on the motor.

 

Hi Rocko - Thanks a lot for these references. Has given me a few other leads to chase down. That ignition switch issue - sheesh - who would think???

 

No problem. Easiest/cheapest is buy an aftermarket blower from Amazon, throw it in. If that solves it you are set.

 

Yep - I opted for the incredibly expensive OEM version. Hope this fixes it....

 

Me too. Please post an update once it's installed.

 

Hi Guys - I replaced the blower assembly with an OEM unit - the problem appears to be solved. Never did find that pesky blower relay. I suspect that the functionality is in the AC amplifier unit. (just a guess though...) The alternator was also bad so it got swapped too - likely the result of the number of times the car needed to be jumped over the last few weeks. All appears to well now. Thanks for your thoughts on this!

 

Good news. Glad it worked out.