My heater blower stopped working on my 2007 Octavia yesterday.

Discovered it was fuse number 4 in the dashboard fusebox.

This 5amp fuse serves the Heating, Air-Coditioning system and reversing lights.

Any ideas how I go about tracing the fault?

I tried disconnecting the blower motor and reversing lights, but the fuse still blows.

I can hear it blow a few seconds after turning the ignition on.

I have exactly the same problem. In fact it seems my Octavia is starting to fall apart rapidly, - designed in failure perhaps. Just had a failed dual mass flywheel, the drivers side wing mirror glass is coming away from it's backing, reversing sensor has gone intermittent.

Help with the heater fuse would be gratefully received!

I had to take it to the dealer after trying all I could to find the fault (I am an electrician, so have a fair bit of electrical knowledge).

In the end they traced it to a faulty sensor in the heating system. Cost about £170 if I remember correctly.

Since then the car has been fine until just recently, when another sensor failed (in the exhaust system), this time a lcoal garage sorted it out for a more reasonable £60.

I'm in the same position - an electronics engineer and I am reluctant to let a garage mechanic loose on it until I've had a go myself. I've disconnected the reversing lights and the heater control unit and I still have the problem. I don't believe the Haynes wiring diagram to be correct as the only thing it shows being fed by FC4 is the heater control unit. Any idea where the heating sensor is located?

No idea I'm afraid, I left it to the garage, it took up too much of my time already.

Wish I could have been of more help, sorry.

Abit vauge but im positive its a short circuit, its time to get your meter out and do some continuity tests mr engineer ;-) a broken live from one of the three to the fuse box touching the body??

Edited 5 June, 201214 yr by 07 vRS Taxi

I'm in the same position - an electronics engineer and I am reluctant to let a garage mechanic loose on it until I've had a go myself. I've disconnected the reversing lights and the heater control unit and I still have the problem. I don't believe the Haynes wiring diagram to be correct as the only thing it shows being fed by FC4 is the heater control unit. Any idea where the heating sensor is located?

If you have the climatronic unit then the temperature sensor is the little shiny black round bit in the middle of the centre dial of the control panel. There is a sunshine sensor on the dashboardjust underneath the centre of the windscreen.

Ian

The first thing I would do is disconnect the high-pressure sensor (G65). Then pull the connector off the reversing light switch. If you have an auto-dimming mirror, disconnect that next. Finally, disconnect the climatronic.

If one of the above doesn't fix it, you'll have to cut the black/yellow wires in the loom from the fuse to isolate the fault.

HTH

Find somebody local with VCDS -- whatever has blown the fuse will have logged a fault code that can be read in seconds. Why waste time trying to trace with a multimeter?

Mike

If only that were true. The climatronic might log a fault that it has lost power or can't see the G65, but neither will help locating the shorted power supply.

Agreed, but it would tell you what component system is at fault, rather than guess climate or reverse lights. No point in checking all the wiring to the climate if there's a short somewhere in the reverse light circuit.

Mike

Unfortunately not. If wire to the reversing switch is shorted to ground the fuse will blow and the climatronic/G65 will lose power. The climatronic will log a fault that it has lost power but that isn't the cause.

I've seen a car with a short on the auto-dip mirror (also fed by this fuse). Only the climatronic logged a fault. There are no intermediate connectors to the various items, so the only way was to cut the wires.

I stand corrected.

A supply to ground short is the one thing that isn't detected (because it blows a fuse and all the items go dead). Signal short to +ve, short to ground and open circuit are detected.

Im guessing the fault is on the live side...lets not forget in which direction electrons flow.

Thanks for all the advice folks. So far I've downloaded the correct schematics from Skoda - (The Haynes manual IS a complete joke)! The feed from FC4 splits two ways, then one of those a further 3. Before delving into the loom I will disconnect all devices that could have failed. So far I've disconnected the two sensors under the drivers side foot well, the reversing lights, and the climatronic control unit. Next will be the dimming mirror and G65 - could somebody tell me if this is only accessible from under the front of the car?

I see HTH says the reversing light switch is fed from FC4. I couldn't see that on the diagram but it makes sense as the car had a new flywheel and clutch fitted a couple of weeks ago and it may have been disturbed.

Thanks again

Cliff

Maybe the connector for the reversing light switch hasn't been put back on the box and is shorting to ground. They may have forgotton to remove it and ripped the wires out.

ps/

HTH = Hope This Helps

I know this was two years ago, but did you find a solution to this? Would be very thankful for a reply on this, as I'm having the same problem with my beloved Octy.. 

Edited 30 November, 201411 yr by stjerneblaa

Today I have no heat either, blew two 5amp fuses and  now it is doing my head in. 

 

Can someone please help or shall i jus go to skoda?

 

Pre-fl octy II 2006 vrs

 

regards 

Maj