I have a 2007 toyota sienna LE. Fuse #38 (HTR 10A Air conditioning system) began tripping causing the blower fan inside the cabin to stop blowing air. Replacement fuses would trip. I replaced the blower motor resistor. The fuses still tripped at both 10 and 15A. I discovered, however, that I could run the blower as long as the air conditioning (including defrost) was not on. I removed the magnetic (compressor) clutch relay and now can run the blower without tripping the fuse. I tested the relay. With 12v across the coil it switches properly. The resistance across the coil is 164 ohms. So the relay seems OK, right? I do not have a wiring diagram. Can you help me find what is tripping the fuse?
Thanks,
Chris
How long has your 2007 Toyota Sienna had this problem?
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Not sure off the top of my head what the resistance through the coil should be on the relay, however if removing the relay cures the blown fuse issue. I would suspect that the magnetic clutch is shorted, since it is powered by the same fuse.
The real test would be to measure the current flow through the wire. At 4.2 ohms with battery voltage of 12.6 Volts would give a current of only about 3 amps. However you could have a winding shorting out when clutch engages or gets hot. If you know what you are doing you could use a DVOM and hook it up in line with the wire with a fused wire with a fuse slightly below the Amp capacity of your DVOM to protect its internal fuse and see what draw you get in real use. I personally would use an amp clamp around the wire to measure, much safer and less risk of damaging equipment.
Clint
Thank you, Accomplished. I checked the resistance across the magnetic clutch coil and got 4.2 ohms, which I think is within specifications.
The real test would be to measure the current flow through the wire. At 4.2 ohms with battery voltage of 12.6 Volts would give a current of only about 3 amps. However you could have a winding shorting out when clutch engages or gets hot. If you know what you are doing you could use a DVOM and hook it up in line with the wire with a fused wire with a fuse slightly below the Amp capacity of your DVOM to protect its internal fuse and see what draw you get in real use. I personally would use an amp clamp around the wire to measure, much safer and less risk of damaging equipment. Clint