Heater Resistor blown again in two months???

[Hotsauce]

The only thing that could blow a resistor consistantly would be too much current. I would think the fuse on the fan would blow before the resistor if it was sized properly though.

Do you know the value of the resistor?

Either the fan is malfunctioning and drawing excess current, or could it be jamming on something in there?

Low voltage can also cause high current draw.

As a temporary step, I would replace the fuses with lowest value that doesn't blow in normal operation.

John C.

[mrlegoman]

I'll take the fan apart and clean it, plus I'll change the fuse as you suggested.
It just seems odd that the fan only works on high, which is why I thought it might be a resistor problem. Thanks for the advice!

[Hotsauce]

I think the resistor is switched in to lower the speed, by consuming some voltage.

John C.

[SGT.BATGUANO]

Isuzu seems to switch the ground or negative for controls in a lot of cases, unlike U.S. vehicles, so check your under dash body grounds behind the kick panels. They have been cited as causing other problems. Otherwise, it may very well be that your resistor has blown again .