Air blower in 1990 RR Classic

The hot/cold air blower runs at settings 2 and 3 only - nothing at setting 1. I conclude that the portion of current limiting resistor used for the slowest speed has burnt out and that the fan is OK. But I haven't made any tests with a meter to prove this (yet). A study of the manual reveals a wire-wound 3 tap resistor buried in the guts of the blower housing.

Dismantling the lower dash and associated other heater related horrors does not appeal. Can I mount a pair of suitably rated resistors in a remote location and wire them into the fan switch? I was thinking of metal bodied multi-watt resistors mounted on some convenient chunk of heatsink (AKA body panel) - maybe on the bulkhead somewhere.

Am I likely to be completely wrong in my assumptions? How do I prove them? If it is a burnt out resistor, does anyone know the value or values of the replacement resistor(s)? I suppose that I could measure the value of the number 2 speed resistor and add one of the same value??

TIA

Richard

Reply to
Richard
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Your deductions sound correct to me. But I don't think your solution will work as you'll be looking to dissipate a huge amount of heat - a quick measure of the fan current in my Hilux (because the resistor is accessible) shows about 8A of draw on the blower motor so that's close to 100W to deal with.

Reply to
EMB

On or around Fri, 15 Dec 2006 16:38:35 +1300, EMB enlightened us thusly:

blower speed resistors are notorious on anything. on the tranny, they're behind the grille in the airflow, other makers put them in the heater inlet ducting.

You can mount a new resistor unit eslewhere if you can find the wiring. You might be able to get to it without removing all the dash, depending on where it is.

Reply to
Austin Shackles

Isn't that why the resistor pack is mounted in the blower airflow, to get rid of the heat!

Reply to
JacobH

Thanks EMB

You're right about the dissipation problem. My initial thoughts were to prove that it is the resistor that has failed, get at the relevant terminals on the switch then think about a suitably windswept location. Behind the radiator grill perhaps? Or even replace the crude resistor solution to current limiting with a solid state solution based around an LM317 perhaps. That raises the possibility of a continuously variable fan speed ;-)

Ta

Richard

Reply to
Richard

That has potential, I'll have a wee bit of an investigate too. School summer hols have just started here so a project like that will shut my lad up for a wee while.

Reply to
EMB

Zactly

Reply to
EMB

Thanks EMB

Don't suppose that you know anything about the construction of RR electric seats? - see my other thread.

Richard

Reply to
Richard

They have a single motor under the base with a cable coming out of each end so one cable drives clockwise and the other anti-clock as the winders have symmetrically opposite contruction. The motor is running ok so maybe the cable or the actual winder mechanism is sticking or knackered/worn out. Sounds more like the winder on one side to me.

HTH Martin

Reply to
Oily

Thanks Martin

Any advice as to whether it's a fruitless task trying to fix them? ISTR something in the manual about winding and unwinding the drive cable.

Richard

Reply to
Richard

Sorry Richard, I can't honestly remember what was wrong with it or how I fixed it, I'll have a look at the parts fiche and see if it jogs the grey matter, I think it may have been the cable end now but not sure.

BTW Watch your fingers in there if I remember rightly.

Martin

Reply to
Oily

Martin

Don't go to any great trouble looking at the parts fiche unless you think it has more info than the paper and CD parts manuals (which, I think, are direct copies of the fiches).

I have both paper and CD copies of the parts books and both only discuss the surface components of the seats.

I'm going to take the seat out of the car and lash it to my Workmate and try to power it so that I can study the action before I start breaking it open.

But thanks anyway.

Richard

Reply to
Richard

"Richard" wrote:-

The seat motors, switches and gearboxes are shown under Body Electrical (Fiche4, J8-J11), which is nowhere near the actual seats and AFAIR were quite easy to get to underneath. If you pull the multiplug you can test it with two wires on a spare battery poked up the opposing side holes in the plug, just swap the wires around to change direction but, as I said before, watch you don't get trapped.

Best of luck with it.

Martin

Reply to
Oily

Thanks Martin

Into the valley etc!

Rgds

Richard

Reply to
Richard

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