Ever since I bought my Land Rover Discovery, the serpentine/drive/auxilary belt tensioner has squeaked. It sounds terrible, like a mouse caught in a blender.

Also, a month or so after I bought it, the rear electric windows stopped working (while they were both open, annoyingly!).

Today, I have fixed them both at the total cost of 1p! :-)

First of all, the squeaky tensioner.

On almost all car engines there is a belt, visible when looking under the bonnet, which runs a complicated route around the front of the engine. It usually powers things like the power steering, water pump etc. and being a belt, must be kept at the right tension (to stop it slipping or snapping).

This tension is provided by a “tensioner”, of course!

On a 300TDi engined Land Rover, however, there is a manufacturing fault (I’m told) which results in all tensioners being fitted at a slightly wrong angle. This results in the pulley rotating off centre and therefore squeaking.

So, having searched LandyZone for the “penny trick” I set about rectifying this problem.

In summary, you have to slacken off the nut holding the tensioner in place, move it forward slightly, insert a 1 penny piece and tighten it all back up again. This results in the tensioner going on at a slightly different angle. The correct angle!


Above you can see the penny as seen from the front of the vehicle and below is the view while standing on the driver’s side of the engine bay looking in.


Having done this, the tensioner no longer squeaks! At last! My engine sounds normal!

Next on my list was fixing the rear electric windows.

One day a couple of months ago, I drove home with both rear windows down (sunroofs don’t work and aircon disconnected). When I got home (in the dark), they would not go back up. I checked the fuses and switches and could not find the problem, so I had to pop along to the garage the following morning and have the wires physically attached to the motors for a few seconds to make them go up. This was obviously a temporary solution, because they still didn’t work after that was done (of course!).

Usually, the next thing to check would be the relay, but in a Land Rover Discovery, the electric windows are controlled by their own dedicated ECU! A reconditioned ECU costs upwards of £100 and my rear windows weren’t worth that much to me so I decided to try and fix it myself.

My fellow LandyZone members then suggested I follow these instructions to see if it would help.

I’m terrible with a soldering iron, but I had nothing to lose, so out came the glove box & window ECU. There is one joint in particular that usually goes, and it was the same on mine.

This is the entire circuit board before I fixed it. The dry solder joint is just below the tiny hole towards the top of the board.


Here is a zoomed in view of the dry joint.


And now here’s the joint after my own dodgy soldering!


So anyway… having put it all back together, the front electric windows and the rear electric windows now work perfectly! :-)

All in all, a good 2 hours work.

It should have taken me 30 minutes or so, but finding the right spanners and removing the plugs from the ECU took much longer than expected!

See various other On-Going Land Rover Maintenance Photos!