Sprint heater blower motor fan

[PeterB]

Hello,

Have a question:

My heater blower just blows on what must be a low level setting ( very quiet ).

I would like to take out the blower motor to have a look and access the resistor more easily on the bench; will it be a straight forward job ( well, as it appears to be to me ).

As far as the resistor replacement if that is needed, what are the specs like watts and ohms for this critter ( looking at Arcol ones at present but its all a mystery re the specs ).

Surely, if the resistor was the culprit, I would get the high speed level....so another mystery.

I've looked at the forums previous deliberations on this topic but it didn't really help me.

Any ideas ?.

Peter.

[tony g]

Youre correct in thinking the resistor gives the slow speed so its not that. resistor is under the bonnet on the outside of the heater box. Has the wiring been played with under the bonnet?There are 3 wires for the heater and on mine a 4th wire which is not used but is live with ignition on. Connection wise going from low to high speed thats on the actual lever on the dash panel. It makes a sliding contact when selecting speeds. It might be worth pulling the 3 knobs off and the black facia panel the levers poke through and have a look in there for a broken or dirty connection.

Tony

[roadster]

I recently fixed mine which had similar symptoms. Found that the wiring was wrong on the three bullet connectors. The power supply wire is green and goes directly to the motor but the other colours don't match across the connectors. The other wires act as earth ( via the switches on the selector lever inside the car ). One goes directly to the motor although sharing a connection with the resistor. The other goes to the opposite side of the resistor to provide slow speed. The selector lever inside the car also has a position where the Bowden cable opens the air vents but the fan is off. Once you are sure that the solid green wire goes directly to the motor connection you can experiment with the other two so that you get half and full speed in the correct selector lever positions. Incidentally I also found that the flexible tubes to the eyeball vents had not been connected.

[PeterB]

Thanks Roadster and TonyG.

I will go out and have a look at next opportunity, hopefully this afternoon.

I recall from looking at the bullet connections last time, there were two connected and one floating unconnected.

Please stay tuned .

[yorkshire_spam]

Are the sprints the same as the 1850s?

[PeterB]

Just checked wires into and out of bullet connectors according to wiring diagram for VA 150001 and onwards rhd and they appear to be joined up ok and I have in fact the 3 bullet connectors and a spare white wire with a connector unconnected sitting in space.

I tried to prise the plastic facia out on the dash but that wouldn't spring out and I don't want to break it if thats what you need to do to check the contact points on the sliders.

So after listening very carefully with engine switched off, the high speed appears to work but its very slow and only slightly faster than slow speed and I thought it would go faster so all in all technically everything is working.
This was like this when I bought the car in 1985 for my late mother and I always thought it might be the resistor so perhaps something else if the fan should go faster .

I will have to replace the battery.

The alternator supplied by the AA back in the 90's is a high power ( 70amps ? ) and is putting out the recharging as it should ( 14.4 volts at battery terminal unloaded ? ).

Thank again.

[roadster]

The easiest way to check the switching is by using an electrical meter that has a continuity buzzer or resistance setting. Even the absurdly cheap ones are good enough for occasional use. First establish which of the four car side wires ( yes including the unused one ) are live when the ignition is on. Ignore these and keep them out of the way. Then with the ignition off and preferably with battery disconnected, connect one side of the meter to earth and the other to each of the two remaining wires in turn. In the two fan on positions of the control lever you should get continuity to earth in one and only one of the wires for each position. If you are actually measuring resistance continuity means below 10 ohms for a typical cheap meter but the audible check is probably better because it forces some current through the contacts and will sound feeble if the contacts are bad.
You can also check the fan motor easily enough by connecting a twelve volt supply to the green wire and earthing the opposite connector. Do this with all bullet connectors disconnected from the car.

[red&black]

If you need a new motor,a Series 3 Land Rover one will fit.

[PeterB]

Thanks roadster and red&black.

I was thinking of hooking up the battery to the motor directly as my next test so I will do that first during the coming week.

I will also try the continuity test with the £7.99 Kendo digital multi tester I bought at the Range awhile ago...it has a buzzer I think.

I was also thinking it might be a failed motor and with the damp climate down here in west Cornwall it doesn't help although the vehicle has always been garaged with good ventilation.

Please stay tuned.

Thanks again.

[PeterB]

Played around with the wires at the motor and got high blow but lost low setting.
The got some smoke off the resistor so swapped the bullet connections back.
So back to where I started except I have the high setting which I didn't have before but have lost the low setting now.
So motor seems to be ok.


I will soldier on some time when I get over this cold I just developed this week.

Thanks again everyone.

Peter.

[roadster]

The resistor might get very warm but if its getting too hot it sounds like its seeing a live connection one side and earth on the other. Given that the interior switch will earth it by design on each side depending on position, that would mean you have an incorrect direct connection from a live wire rather than via the motor only. It should only see twelve volts via the motor connection when there is no current flowing, i.e. the switch is in the no-fan position or the off position and the resistor is not earthed on either side. I don't know exactly what type of electric motor is used but its quite likely that if you do have a live feed direct to the resistor the motor will be running in the wrong direction.