Toyota Avensis D4d Blowing Heater Motor Fuse

[Geoff Cummings]

Hi,

I have a Toyota Avensis D4D which keeps blowing the fuse for the heater motor.

If I put a new fuse in and switch on the ignition key (without starting car) with the heater switch turned on, the fuse will blow.

If I start the car and put a new fuse in, I can turn the fan on and it works and does not blow the fuse.

As soon as I turn the car off and on again the fuse will blow.

The problem has started around the same time as the alternator was changed. I have tried disconnecting the alternator but it made no difference.

Hoping someone has an idea :)

many thanks

Geoff

[Q.S.]

Hi,

I have a Toyota Avensis D4D which keeps blowing the fuse for the heater motor.

If I put a new fuse in and switch on the ignition key (without starting car) with the heater switch turned on, the fuse will blow.

If I start the car and put a new fuse in, I can turn the fan on and it works and does not blow the fuse.

As soon as I turn the car off and on again the fuse will blow.

The problem has started around the same time as the alternator was changed. I have tried disconnecting the alternator but it made no difference.

Hoping someone has an idea :)

many thanks

Geoff

With the engine running the voltage is higher (alternator lifts voltage to around the 14 volt mark), when the voltage is higher, the current is lower (amps) hence the fuse stays intact. On ignition only the voltage is lower and therefore the current draw is higher, high enough to blow the fuse. (10 amps at 14 volts, 11.66amps at 12 volts for example)

That explains why there is a difference but the fuse should be ok in either situation, the heater motor must be drawing excessive current to blow the fuse.

Are you sure that the fuse you are fitting is the correct rating?

[Mallion]

Hi. Can I ask the location  of the fuse for the blower motor ? I’m having trouble locating it

[Konrad C]

I already answered your question on you original post, before you posted this new request on this old thread! 

This post may be related to previous generation Avensis, due to the original date. T27 would have been very new, and under warranty.