2003 4Runner Heater Blower Not Working

[billr578]

Hi,

I have a 2003 4Runner V8. A couple weeks back I took it in for service at the local dealer to have the AC looked at (wasn't blowing cold). After there and about $210 in labor, they told me the electrical system was messed up. While they were testing they claimed the dome light stopped working and then the blower gave up. Apparently they found remnants of a mouse house in the engine bay and were pointing at mice having eaten through the electrical system somewhere and causing a short.

Anyway, not wanting to buy a new 4Runner I went digging in my own. Dome light wasn't working because the relay was missing from the fuse box! Seems like they forgot to put one back in. So that got me thinking that maybe they messed up something on the blower or heating/cooling system. Took the dash apart - nothing out of place. Tried replacing the heater relay, blower, and resistor and still nothing. All the fuses seem check out as well when tested. Is there anything else I could be missing or could test before I throw in the towel? Love my 4Runner and would hate to have to get rid of it. I have the whole service write up as well if that'd help. Thanks!

-Bill

2003 V8 4Runner Limited
Bill Rowell

 

[asahi4runner]

Hi,

I have a 2003 4Runner V8. A couple weeks back I took it in for service at the local dealer to have the AC looked at (wasn't blowing cold). After there and about $210 in labor, they told me the electrical system was messed up. While they were testing they claimed the dome light stopped working and then the blower gave up. Apparently they found remnants of a mouse house in the engine bay and were pointing at mice having eaten through the electrical system somewhere and causing a short.

Anyway, not wanting to buy a new 4Runner I went digging in my own. Dome light wasn't working because the relay was missing from the fuse box! Seems like they forgot to put one back in. So that got me thinking that maybe they messed up something on the blower or heating/cooling system. Took the dash apart - nothing out of place. Tried replacing the heater relay, blower, and resistor and still nothing. All the fuses seem check out as well when tested. Is there anything else I could be missing or could test before I throw in the towel? Love my 4Runner and would hate to have to get rid of it. I have the whole service write up as well if that'd help. Thanks!

-Bill

2003 V8 4Runner Limited
Bill Rowell

Get a power probe and jump the blower to see if it works

 

[billr578]

Get a power probe and jump the blower to see if it works

I already tried a new blower motor with negative results so my guess I that there is more wrong than just the blower. I'll start testing the electrical system back at this point though. Thanks.

 

[asahi4runner]

Yeah start by checking to see if you are getting 12volt to the motor

 

[BlackWorksInc]

I can't remember if the 4th gens use the older style resistor or the newer style pulse width modulated blower system. One means you can test it easily... the other means it needs to convert a modulated signal into fan speed and could indicate an issue with the HAVC controls and/or Blower Module.

 

[billr578]

I can't remember if the 4th gens use the older style resistor or the newer style pulse width modulated blower system. One means you can test it easily... the other means it needs to convert a modulated signal into fan speed and could indicate an issue with the HAVC controls and/or Blower Module.

I just tested for voltage at the plug for the blower and it didn't measure anything. Verified the multimeter worked on a AA battery and it read properly.

 

[billr578]

I just tested for voltage at the plug for the blower and it didn't measure anything. Verified the multimeter worked on a AA battery and it read properly.

For what its worth, the VSC lights are on as well (VSC Off and VSC Trac I think).

 

[bgebhard]

Any luck on this fix, I am having the same issue.

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