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Discussion Starter #1
Ok. My '99 RR 4.0 Gems - she's running great finally. But now ... it's getting cold here in Minnesota, and she decides to lose all heat. Problem 1: the climate control round knob does nothing. I so wish it was a direct knob-to-blower control, but it's not. It just sends the computer the temperature you want and then the computer makes it happen. But. Is there not a manual override? I need HEAT! Problem 2: the blower on the driver's side sounds like a shot bearing or something. Taking the Climate Control unit out tonight, will inspect, then there is a place in California to send it to for a rebuild for $100. Not sure if this is a good idea...
Then, I'm going to take out the blower unit and see what's there - maybe a mouse nest?
Then, I'm stuck! All I want is a direct manual on/off switch for the blower. To survive.
Any ideas? Thanks,
Kevin in Minnesota.
[email protected]
 

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Just put it in Auto, it controls the fan speed automatically. You set the temperature you want and as soon as the heater core is hot enough, the fans speed up to get the interior up to what you've set. That assumes you don't have the book symbol showing on the HEVAC as that means it has detected a fault and shuts down whatever part of the system that is at fault. If you take the pollen filters out, you can see whatever it is that is causing the noise from the fan.
 

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I wd check your coolant level first - if that has dropped then it will reduce the flow to the heater matrix. See if the ali pipes going through the bulkhead to the heater matrix are hot. Just one? Or both... Blow out the internal temp sensor with comp. air. There is a manual over-ride on the round switch, but it wears - on mine you have to go round and round a few times to get from slow to fast - or just hit auto in the centre - if the sensor inputs are correct, then it should work. You can also disengage aircon on the hevac controller, but I suspect a/c won't be on anyway
 

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Discussion Starter #4
I appreciate you guys are trying to help but ... this is my old project car - I've rebuilt most of the usual problems myself with the help of youtube and atlantic british. IT has 205k miles, so to be expected, parts are wearing out. So ... the heater core is new and it's not losing coolant. Coolant level is perfect. The climate control screen is dead. Warning lights in dash are disconnected. The auto button is not working at all. If I disengage the a/c on the hevac controller, will that make any difference?
Here's what I suspect: the contacts on the circular knob are all worn off. Plus, the blower motor has shot a bearing. Anyway, taking control unit out today, and blower out tomorrow. Then, clean and diagnose ... hoping to find a nest of mice in the blower area and then all's well. But, fat chance.

Thanks, KO
 

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1995-2002 Range Rover P38A
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Your blend motors might be stuck. If you have a magic box, you can cycle the various blend motors to see if they work. Do you have a spare control unit you can put in?
 

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Discussion Starter #6
Blend motors - good thought - but they are solid. Had that problem about 5 years ago, decided to bypass what I considered a flawed system - hooked up some old stiff coat hanger wires to the levers that control the flaps, routed them to the dash, and they've worked great ever since. A simple on/off solution. I could not stand the thought of spending $400 each for the blend motors, only to have their idiotic plastic gears break again. UK designers do not know about sub-20 degree F temps and the effects on plastic.
 

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Well I guess we were missing the fairly crucial "controller may not be working" , rather than just the dodgy rotary switch !! So now we work on the basis there probably IS a service manual sign. Do you have Diagnostics? You need to clear the faults - not sure how the HEVAC will react with your cunning blend motor fix in place, especially if it has encountered other issues.
I need to fix the rotary switch on mine too, but I read that that switch can be removed and the metal contacts cleaned up and bent back into place to apply a little more pressure to the opposing contacts.
I fixed the screen on mine with a £5 ribbon off ebay.
Disengaging the a/c would only make a difference if the a/c was supplying COLD/ ambient air (via the blend doors) - eliminates one possible factor, that's all.
We still need to know if you have a hot heater matrix (on both pipes), and there's a sensor on one of them too. If you replaced the heater core then a lot of things will have been disturbed...
You could try pulling the relevant relays to isolate the blower motors and isolate the squeal from the blowers. Nanocom wouldn't help you separate the blowers it turns both blowers on/ off at the same time (although there's your manual override, right there)

After that then there are the sensors to consider (Nanocom is useful for that) and after that you may need a probe and the ETM
 

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Discussion Starter #8
All good thoughts. For now, I just want to re-assemble the unit as it was and get at least a hint of heat. Then, remove the driver's side blower/motor and inspect. Then, I dunno. Wish there was a way to hotwire the blowers to on/off ... I'm not smart enough ... will report further as things progress ... if I don't freeze to my death! It's well below zero (F) here, and will be for while. Maybe I can find a 12v electric heater - now there's thinking!
Thanks for the helpful suggestions...
K
 

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Kevino,
Seeing as you have already pretty well butchered the HVAC, the "Controller" is a write off. Might as well go all the way and when you remove the blower, simply bypass the PWM speed controller and run the 2 wires from the motor to a toggle switch on the dash. ON/OFF as you wish. If you wanted to get really sexy, you can find a resistor type switch from a 52 Chev. and you will have a 3 speed blower! Or wire the 2 blowers to a switch so you can hook them in series for 1/2 speed, or parallel for full tilt boogie!!
So, with manual control of blowers, and true manual control of flaps, you can have all the heat you want. Come summer, I am sure we will hear back from you asking how to turn on the A/C! ;)
Rangerover70,
Is it blowing cold air? or not at all? If cold air then: Blend motors.If not blowing, blower control module.
 

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Sorry to say this, but it looks like you butchered a system you don't fully understand...
The information about removing the blend motors and replacing them with a coathanger wire is crucial. I can relate in a way, having no heat or too much heat because the blend motors fail can be very frustrating, and myself and others have pondered fitting a more simple system, like the cable control in a Range Rover Classic or Defender.
But I fail to see how you can complain about no heat and blame the fan speed button with this bodge of the blend motors? It only controls the fan speed, not sends the computer the temperature you want and then the computer makes it happen. I'm with bolt, seeing as your HVAC unit is not doing much anyway (have you fitted the distribution flap motor with a coathanger as well, or is that still using a blend motor?), I'd just fit a simple fan control switch.

Filip
 

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Discussion Starter #12
UPdate: Heater is fixed! The blower motor spun fine. But the relay contacts inside the motor assembly were carboned-up, so I sprayed 'em with MAF cleaner and scrubbed with toothbrush, re-assembled and plugged in - motor ran fine and strong. But when re-installed into the plastic housing, made horrible noise. Turns out to be: when I put the motor back into the housing, I didn't get it in all the way. Fixed that and now all is well. RE: hevac/AUto comment - Don't have any lights on the display, so no idea if on auto or not. Am getting new bulbs/kit soon from UK, will report then. But for now - I'm warm!!! Thanks.
 

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I sent my controler out for rehab a couple of years ago. They replaced all the back lights, fixed the ribbon that controls the display, and fixed the rotary knob for about $100.00 with a lifetime warranty if it was never opened. They bench tested it for every function. Slapped it back in and perfect since. One of the best $100.00 i spent on her.
 

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My 1999 isn’t blowing hot air on the passenger side any suggestions for me

Jason
I just had the problem of one side not getting hot. I replaced the blend motor on that side and cleaned my hvac circuit board. I spilled coffee on it. It is working again but I am not sure what fixed it.
 

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UPdate: Heater is fixed! The blower motor spun fine. But the relay contacts inside the motor assembly were carboned-up, so I sprayed 'em with MAF cleaner and scrubbed with toothbrush, re-assembled and plugged in - motor ran fine and strong. But when re-installed into the plastic housing, made horrible noise. Turns out to be: when I put the motor back into the housing, I didn't get it in all the way. Fixed that and now all is well. RE: hevac/AUto comment - Don't have any lights on the display, so no idea if on auto or not. Am getting new bulbs/kit soon from UK, will report then. But for now - I'm warm!!! Thanks.
Hey there when the screen does not display it is usually the ribbon connector falls off. The company module repair pro in sherman oaks ca does the fix for 100. They did mine a while back. It could be the backlight bulb if not they can fix it.
 
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