Heater blower wiring (MA61)

[Brett]

Hi everyone, long time since I've been on here

I am in the process of making my MA61 roadworthy, it's been out of action for well over a year now. One of the things it needs to pass the roadworthy is a working heater fan. When I was a bit younger, I decided it would be a good idea to remove almost everything under my dash to save weight, stuff like the AC box, heater blower, all ducts and vents...now I am regretting it as I need to put it all back in.



The other day I bought an RA60 for the parts I need, as the original ones I took out are long gone. Fortunately everything looks very similar from what I can remember. I've been putting it all back piece by piece, but I've run into a small snag. Well, not really small, I've spent the past two days trying to figure it out.

The problem is that the heater blower does not switch on.

Luckily the the heater blower works fine in the RA60, so I've been able to use it to test the breaker and the relay. The wiring looks like this power wise:





So far I've worked out that I have power all the way up until the wire I've labeled "TO HEATER BLOWER MOTOR". There is nothing wrong with the breaker or the relay. I thought the problem might have been the switch, but they both work fine in the RA60 (the MA61 switch and the RA60 switch).

Here is the wiring from the switch:


The two green wires just go to a green LED behind the control panel (never seen it working, must be something to do with the aircon). The furthest right blue wire with a black stripe goes to the heater blower. The white wire with a black stripe goes through the firewall (I'm guessing it's a ground). These both continue through the white plug which connects the fan control panel:



I've slightly pulled it out the white wire with a black stripe here:


All I've worked out is that the white wire with a black stripe is essential (the blower doesn't turn on without it connected on the RA60). As for the other colours, they go to various plugs on the AC box.

The heater blower works fine in the RA60 without any of the AC box plugs plugged in.

My best guess now is that the white wire with the black stripe is the culprit, as I haven't managed to trace it into the engine bay precisely. I think it goes to the bottom of the fuse box next to the battery.

So yeah, this is driving me mad as I have absolutely no knowledge of electronics. I bought a multimeter today and managed to work out a few things, but I don't know what my next step should be. I only want the heater fan to work, I am not even going to attempt to fix the aircon (most of the plugs don't match up from the RA60 AC box anyway).

I'd be very very appreciative if anyone could point me in the right direction, I've been going two days straight on this!

Cheers.

[CrUZida]

W-B wire will be earth! Hence its requirement!

The blower will only work in HIGH speed without the blower resistor installed.
The ignition also needs to be ON for the fan to work.

Are you using the TSRM wiring diagrams?

Apart from that, I can offer no further help.

[Rhyno]

Hmmn Brett,

That is a pain in the arse. I would reccomend checking for conduity between a good earthing point (like say your door hinge) and see if thats connected.

Using your multimeter turn it to the setting that has an arrow looking thingy on it, and when you touch the leads together it should beep.

Put one on a good earth (a bare bit of metal thats why I surgested the door hinge) and one on the white wire. If it beeps its connected. If not thats your problem, earth if and you will be laughing.

Secondly test for power at your fan. Put the negative of the door hinge again and make sure you are getting power to your relay/breakers.

If this is all good and If it beeps, find where the wire goes and measure the resistance through your wire (from one end to the other). It could be that the wire is corroded inside and stopping the fan from getting the correct amount of voltage/amps it requires.

Let me know what you find out.

Best of luck!

Ryan

[takai]

Nah, there is some relay that you have to bypass to get the RA60 gear working with the MA61 wiring.

I took a photo of it ages ago, but i cant find it now.

[Brett]

Thanks for the advice everyone

I bought some wire and a toggle switch today and I've managed to get it working by just running it straight off the battery. Once I worked out how a basic electrical circuit works, I managed to wire it up to the lever on the control panel. I guess it isn't a great idea to run it straight off the battery, but as the circuit didn't have any fuses it should be alright yeah? It only works on high of course, but that should be enough for it to get a tick on the roadworthy sheet One cool feature is that it works without the ignition this way

[CrUZida]

Just make sure you fuse that wire and it will be fine to run off the battery.

[Brett]

Ah good idea, any idea what sort of amperage I should use?

[CrUZida]

10A will suffice, but it depends how big the wire is.

[Rhyno]

Your welcome mate,

Cruzida is proberly right, but just in case is there any ratings on the motor?

Like Amps, Volts, Watts or anything?

Worse case scenario, put a 10 in if that pops, put a 15 amp fuse in. Just don't exceed the current limitations of your wire and you will be fine.

Best of luck at the pits!

Ryan