billwade98

The heater/ac blower stopped working on my 2004 Lexus GX470. All the lights and display work but the fan doesn't work on any speed. I replaced the relay in the fuse box under the hood but no luck. I removed the blower and it works when I hot wire it to the battery. I checked the voltage coming into the blower and its at 13.5V, same as coming off the battery but it doesn't turn the fan. Looking for some help.

Thanks,
Bill

mswtoyota

If you have 13.5VDC at the fan and it is not turning, then it probably needs to be replaced. Brushes or commutator may be bad. I have seen intermittent fan motors before, so you might smack it around a little bit while you have it out.

billwade98

The blower works if I hot wire it directly to the battery but when I connect it to the connector, even with 13.5V at the connector with the car running, it doesn't work. Appreciate any ideas on this before I bring it to the dealer. If they had a Haynes book on this I'd be in good shape but no such luck. But not working with 13.5V at the connector doesn't make sense to me.

mrblister

Based on what your saying sounds like there is a problem with a relay or a ground or some issue with a sensor ?

billwade98

Wanted to provide an update on this and potential assist others with similar problem.

When I determined that I was getting 13.5V at the fan connector I assumed the fan was bad. I got a new fan and it wouldn't work either, but it worked if I hot wired it to the battery. I could hear the relay click when I changed the heater setting from off to high so I figured the relay was good and I had already bought a new relay early in the troubleshooting.

Next step -- With the heater on high the fan connector read 13.5V but I decided to test it with the fan connected and with it connected it read zero Volts. I replaced the resistor and problem fixed. Must have been a short in the resistor. I was under the impression that usually the resistor will work on one speed if its bad but not the case here.

mswtoyota

Thanks for getting back to us with the solution to your problem. I think the blower resistor on the GX is actually pulse width modulated, so I guess there was enough voltage, but not enough current supplied to run the blower motor.