Morning all

 

Since we bought it 3 years ago, my wife's Octavia Mk1 (04 Diesel, ALH 1898cc) has had a fault. Each time the ignition is switched on, the oil pressure warning light (little oil can picture on dash) flashes 3 times then goes off. The cause of this has been something that has steadily driven me around the bend for the last 3 years, but has now finally been solved and I wanted to share in case it helps anyone else out.

 

Symptoms we experienced

Oil can warning light on dash flashes 3 times when ignition starts

Air Con does not work

Air con re-circulation does not work

 

Things I tried

Replacing Oil Level sensor in bottom of Sump (twice with new parts) - No change

Checking wiring from Oil Level sensor with mult-imeter - all working

Replacing Bonnet Catch sensor (twice) - No Change

Checking wiring from Bonnet catch sensor with multi-meter - all working

Unplugging Re-circulation motor behind glove box - no change

Checking wiring to re-circulation motor with multi-meter - all working

Checking wiring to air con compressor - fault discovered - wiring had chafed through. Repair with solder and heat shrink - fault still occurred.

 

At this point, I noticed that the common thing to all these components was that they all passed through the same fuse in the fuse board beside the drivers door - specifically Fuse 5 (7.5 amp). This fuse was blown and I replaced it before testing each of the components.

However, it continued to blow at random intervals from 30 seconds to 5 minutes and it was not affected by the activation of any of the components running through it.

 

I bit the bullet and took the car to some professional auto electricians. They identified that it must be a wiring short leading away from the fuse board. What became telling was that the fuse actually blew when the drivers door was opened or closed. Pulling the wiring loom from behind the fuse board where it runs into the area of the chassis near the door, a wire was found to have rubbed against the sharp metal of the chassis. This was repaired and the problem was solved.

 

This fault has cost me over £200 in various parts and more time than I want to think about, but we now have working air con and no flashing oil lamp! 

Hope this helps someone out there  

 

 

I suspect your post helped many people, but as their problem goes away they quickly forget to say anything to acknowledge the person who’s info helped most. This is a bit like the inverse of consumer complaints. You only hear the complaints but never the satisfaction or pleasure of resolution. Funny old world. The worst ones are the humans.

The wiring loom on the oil level sensors sometimes get watèr in and corrode the pins on the plug which causes a short and the fuse to blow.

 

The yellow oil light flashes and beeps 3 times on start up to indicate a fault.

 

Also, as I discovered, there are 2 different types of oil level sensor, both look the same but they are not interchangeable. 

Edited 5 September, 20205 yr by Paul thornton