92' L Series Heater Blower

Dave72 · Post by **Dave72** » Thu Jan 05, 2012 12:30 pm

G'day all,

I'm having a hiccup with the blower motor in my 92 L Series wagon. After a hot day a couple of weeks ago, I restarted the car after a short break and popped the two 15amp "heater" fuses.

I inspected all the wiring and found two wires had shorted out under the clutch pedal, which I cut out and repaired. However after replacing the fuses, the blower does not work.

I tested the blower motor direct from the battery, it works fine, the brushes inside the motor still look okay too.

I also confirmed there is 12 volts going to the blower as soon as the ignition is switched on (even though the fan switch is off! - which also makes me wonder how it is earthed because both blades on the plug to the blower have 12 volts???). Huh?? I thought you could only have one positive and one earth? Or does the switch operate some relay that earths somewhere else? I'm confused!

If I switch the A/C on, the compressor engages when the fan switch is turned on (even though the blower doesn't start up), which makes me think the fan switch is still okay.

Any ideas? And just out of curiousity... why are there 2 x 15 amp fuses on separate circuits?

Cheers,
Dave

YouTube · Post by **El_Freddo** » Thu Jan 05, 2012 2:52 pm

Dave, I've not really looked into it that much but the issue you could be experiencing is that the resistance wires (after the blower) could be damaged/too resistant or the switch could be faulty, although the faulty switch one doesn't make sense as the AC still kicks in...

As for the power on each side of the fan, it could be the wiring you've played with or it could be the wiring circuit with the switch on the earth side of the circuit and not the positive side if that makes sense.

This L series seems to be a pot load of fun for you!

Cheers

Bennie

Dave72 · Post by **Dave72** » Fri Jan 06, 2012 9:19 am

Yeah, I was thinking there has to be some resistor for the different fan speeds, but I've got no idea what it looks like, or how I could test or replace it. I was under the impression that when the fan is on full speed, the resistor is bypassed (the fan doesn't work on "4"), but I don't have much of a clue about this sort of stuff.

I'll probably just wire in a manual switch directly to the starter motor and toggle between off and warp speed (which is a slight breeze now that all the vacuum hoses are leaking and not controlling the actuators properly!).

spike · Post by **spike** » Fri Jan 06, 2012 11:29 am

you probably know more about it than me but id go though and check all the wiring again

YouTube · Post by **El_Freddo** » Wed Jan 11, 2012 12:54 pm

Dave72 wrote:Yeah, I was thinking there has to be some resistor for the different fan speeds, but I've got no idea what it looks like, or how I could test or replace it. I was under the impression that when the fan is on full speed, the resistor is bypassed (the fan doesn't work on "4"), but I don't have much of a clue about this sort of stuff.

The resistors are built into the air ducting on the driver's side of the fan ducting assembly. If you pull the fan out with it's "house" you'll come across come plugs that connect to these resistors in the ducting. I don't know if the full speed fan setting 4 is located in this area as well or not.

Have you made any progress other than what you've already posted here?

Cheers

Bennie

Dave72 · Post by **Dave72** » Wed Jan 11, 2012 2:42 pm

So far I've just wired a "temporary" switch direct from the battery and setup a new earth lead from the blower.... "just to get me out of trouble." It's dodgy, but at least I used an inline fuse! To make matters even more dodgy, I cable tied the actuators closed so that the air no longer goes to the feet vents (I couldn't find the vacuum hose leak).

I'm pretty sure I've fixed all the wiring faults and I've now cable tied everything well away from the pedals (the original wires jammed between the clutch pedal and adjuster screw at the top of the pedal cluster).

There's obviously something else that was damaged when the two fuses blew, probably that resistor, but I can't test it. It doesn't seem worth diassembling all the ducting and finding another unit from a wreckers if I'm not 100% sure where the fault lies. Something tells me there will be a cheap L Series in the ausubaru classifieds in another couple of months... I just don't have the skills to keep this thing going!