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Discussion Starter · #1 ·
I just bought my Rover and got a great deal because it needed Head Gasket repair. Before I did the job the climate control would power up but the fan wouldn't work. Now that I have done the HG job the unit won't power up at all. I have checked all of the fuses and they are all fine. I am kinda stumped. There are quite a few people around here parting out discos and I'm wondering if I should swap out the controller.
 

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What Rover and year do you have?
 

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Probably an 03/04.

The head gasket job shouldn't have anything to do with the controller. I would double-check on the various connections underhood. There are a couple of grounds that sometimes get missed.

If you have not done so, download a copy of the RAVE manual. it's a bitch to navigate, but there is a breakout of every system. There's also a separate wiring manual. You can pull the controller and check for power. Removing the unit is tricky. You need a tool- like a piece of credit card plastic.

If there are people parting trucks out there, you should be able to get a controller for ten bucks or so. Probably easier than the diagnostic.

I would strongly suggest looking at the owning-a-Discovery threads for the common maladies with this truck. Your head gasket probably blew because of one or more of them. You may have found this out, but most head gaskets pop because the temp gauges are useless on these trucks. The needle only moves once the engine experiences damage.
 

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I haven't looked at the schematic, but, and this is if we are talking about the same "resistor", that piece is used for regulating fan speed, I wouldn't think they would run the power feed to the control unit through that piece. In the Rave AC section, they simply reference it as how any other blower resistor might work, with power being fed to it from the blower control.
 

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A friend of mine suggested it might be the resistor.
The resistor usually only controls the lower fan speeds. With the resistor gone, the highest speed will usually still work. If it did not work on any speed setting, it would most likely be another issue.

There is more than one fuse involved. This is the start of the RAVE CD section dealing with the electrics. There is a lot more detail there if you want to look.

OPERATION
Air Conditioning Supply
Circuit supply
A feed from the battery positive terminal is connected on an R wire to the engine compartment fusebox. The feed passes through fusible links 1, 3, 4 and 8 and fuses 5, 6 and 13. Fusible links 1 and 4 are connected in series. Fuses 5 and 6 are also connected in series with fusible link 1.
The feed from the battery is also connected directly to the contacts of the main relay in the engine compartment fusebox.
From fusible link 3 is connected on an NR wire to the passenger compartment fusebox where it passes through fuse 20.
The feed from fusible link 4 is connected on an NK wire to the passenger compartment fusebox where it passes through fuses 6 and 7.
The feed from fusible link 8 is connected on an NW wire to the passenger compartment fusebox and from the fusebox to the ignition switch on an N wire.
Ignition switch supply
When the ignition switch is in position II, the feed from fusible link 8 flows through the ignition switch to the passenger compartment fusebox on a W wire and passes through fuse 31.
From fuse 31 the feed passes on a GK wire to splice joint A9/A144. From the splice joint the feed is divided into three separate feeds as follows:
• A GK wire supplies power to the Air Temperature Control (ATC) ECU.
• A GR wire supplies power to the in-car temperature sensor.
• A GR wire to connector interface C0765-1/C0778-1 changes to a LGW wire to splice
joint A1. From splice joint A1 the feed is connected on a LGW wire to the fresh/ recirculated air mode motor. A tapping from splice joint A1 passes on a LGW wire, via splice joint B1, to the coil of the blower relay. From splice joint B1 a second LGW wire is connected to the coil of the power relay.
Front Air Conditioning Operation
Air temperature control ECU supply
A feed from fusible link 3 in the engine compartment fusebox is connected on an NR wire to the passenger compartment fusebox. The feed passes through fuse 20 and is connected, via header C0725, to the Air Temperature Control ECU on a P wire.
Main relay/inertia switch supply
A feed from fuse 13 in the engine compartment fusebox is connected to the inertia switch by a NB wire. When the inertia switch is closed (not tripped), the feed continues on a WG wire to the coil of the main relay in the engine compartment fusebox. The main relay coil is then connected from the relay to the Engine Control Module (ECM)) on a UR wire. When conditions are correct, the ECM provides the earth path which in turn energises the main relay, closing the contacts.
Cooling fan relay supply
A feed from fuse 5 in the engine compartment fusebox, is connected to the contacts of the cooling fan relay.
Cooling fan motor operation
When the main relay is energised, a feed passes from the relay contacts to the coil of the cooling fan relay. The cooling fan relay coil is earthed on a BP wire (Td5 engines) or a GW wire (V8 engines) to the ECM.
When conditions are correct, the ECM provides the earth path which energises the cooling fan relay coil closing the contacts. The feed from fuse 5 in the engine compartment fusebox passes through the cooling fan relay contacts and from the fusebox to the cooling fan motor on a BN wire. The feed operates the cooling fan motor which is connected to earth header C0018 on a B wire.
 

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You're wrong again, Ian. I didn't say it controls ALL fan speeds.


What you gave the OP is useless. Without a schematic and an index, you might as well have posted instructions in Sanskrit. You ignored the fact that the control unit doesn't turn on. What he needs is to know what wire in the plug supplies the control with 12v+ to see if the unit is getting power.
 

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You're wrong again, Ian. I didn't say it controls ALL fan speeds.


What you gave the OP is useless. Without a schematic and an index, you might as well have posted instructions in Sanskrit. You ignored the fact that the control unit doesn't turn on. What he needs is to know what wire in the plug supplies the control with 12v+ to see if the unit is getting power.
You are a moron!
He had stated that he had checked the fuse and it was OK.
The information I posted states how there are a number of fuses and where they are.
So it gives him a list of basic things to check before he starts pulling his car apart.
 

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Wouldn't it make more sense than trying to sort through the vastly incomplete information you provided, that he pop the unit out and probe the power wire? If the head is dead, why tear the whole electrical system apart. What you gave him is useless without the diagram that it references and a legend for the various abbreviations.

I can only presume you have never worked in a shop on customer's cars for a paycheck. Your diagnostic approaches are absurd. You'd starve on flat rate.
 

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Wouldn't it make more sense than trying to sort through the vastly incomplete information you provided, that he pop the unit out and probe the power wire? If the head is dead, why tear the whole electrical system apart. What you gave him is useless without the diagram that it references and a legend for the various abbreviations.

I can only presume you have never worked in a shop on customer's cars for a paycheck. Your diagnostic approaches are absurd. You'd starve on flat rate.
I do work for a quoted fixed price, rather than by the hour. And yes, I do sometimes stuff up the estimate about the time required and costs of materials. Sometimes I complete it quicker and less materials are required, sometimes slower and more materials are required, but it all balances out.
Unlike you, I would check the fuses first before pulling the car apart. But just call be crazy for doing that.
Again, your comments are just attempting to divert the thread. I will not be responding to anymore of your useless posts in this thread.
 

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I do work for a quoted fixed price, rather than by the hour. And yes, I do sometimes stuff up the estimate about the time required and costs of materials. .
"Stuff up"? An appropriate term. Like "I really stuffed it up their ass on that one"?

If you repair cars the way you advise others, someone is taking a serious boning. If I brought you a car with a dangling coolant sensor, just how much of my bill is going to be your research into how the ECU processes the signal from that sensor? Does everyone get an antifreeze boil research test, like a shop supplies fee, just built in to the bill?
 

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Discussion Starter · #14 ·
I found the issue. There is a broken wire in the wire harness supplying power to the controller. I ran a new power line and everything turned on the way it should. Even my side mirrors work now. Not sure why.

On to the next issue :)
 

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Discussion Starter · #16 ·
Hey, it is what it is. Now I'm trying to figure out how to fix my rear pass window. New motor, new switch, but it will only go down. I like fresh air but there are times I want the Rover closed up. Eventually I'll figure it out.
 

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Alot of times you'll find internal breaks in the wiring loom in the section between the door jamb and the front face of the door. It flexes and breaks internally. Looks OK from the outside. We have a bunch of F250's and it always happens in the passenger door on just about every one of them. That's weird because that door gets a tenth of the use as the driver's, but go figure. Have someone work the switch and then manipulate the loom.
 
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