A160 intermittent heater fan

[geraldreme@tiscali.co.uk]

My heater fan is intermittent thus not allowing heating or A/c. It may last only one trip or 4 or 5 days, when it will start operating correctly. When working both the heater and A/c are brilliant but when they are not it poses a safety problem with no demisting!
I have changed the fan/heat/airconditioning control panel(from an insurance write-off), fan motor and the resistor pack all to no avail.
Is there a relay in the circuit that may be playing up?
I really do`nt know what else to do---can someone out there help me please?
THANKS
GERRY

 

[mattkh]

Hi
Under the drivers footwell is the battery compartment. You will find a folded paper there. Scan/photograph it and put it up for us.

 

[jberks]

you seem to have replaced everything but the wiring!
What diagnosis have you done? I get the impression that you've simply replaced everything without fully understanding how it works in the hope that you must have replaced whatever was defective. Those parts can't all be faulty and there's no point replacing perfectly good components blindly.

The resistor pack controls the fan, using power on a constant 12v based on a variable control signal from the switch. It then puts out an appropriate voltage to the fan, and the fan turns. Simple as that.

So, when it's not working, do you get power to the resistor pack? Do you get a control signal to the resistor pack and does it change with the switch position? Is there a decent earth? If everything to the resistor pack is ok then what about power out to the fan. Does the fan have a decent earth?
The system isn't very complicated when you think about it, could be a dodgy fuse, poor earth etc but you really need to go back to first principles, do a basic diagnosis and figure out what is missing.
Let us know what you find.

 

[jdgomez]

you seem to have replaced everything but the wiring!
What diagnosis have you done? I get the impression that you've simply replaced everything without fully understanding how it works in the hope that you must have replaced whatever was defective. Those auto parts can't all be faulty and there's no point replacing perfectly good components blindly.

The resistor pack controls the fan, using power on a constant 12v based on a variable control signal from the switch. It then puts out an appropriate voltage to the fan, and the fan turns. Simple as that.

So, when it's not working, do you get power to the resistor pack? Do you get a control signal to the resistor pack and does it change with the switch position? Is there a decent earth? If everything to the resistor pack is ok then what about power out to the fan. Does the fan have a decent earth?
The system isn't very complicated when you think about it, could be a dodgy fuse, poor earth etc but you really need to go back to first principles, do a basic diagnosis and figure out what is missing.
Let us know what you find.

Jberk's right. Maybe you've got the wiring all wrong. Update us immediately on what happened.

 

[jberks]

Jberk's right. Maybe you've got the wiring all wrong. Update us immediately on what happened.

err - Mr Gomez - why have you added a link to my post?
Spam i assume - we don't take that kind of behaviour well on here.

Also, FYi - there is a small island off the coast of Europe (New York, head East and keep going and no, not Ireland) called "England". Thats where we are, so there's not a lot of point spamming us with a dodgy link to a US based site.

 

[geraldreme@tiscali.co.uk]

thanks jdgomez; the system does seem quite basic but when it is not operating there is not any voltage at fuse 45---is this supplied from the ignition switch or is there a relay in the feed to fuse 45?----its a 30A fuse which leads me to believe there may be a relay to "soften" the switching. Let me knowhat you think
thanks