My t reg ren megane immobilised and radio has stopped working ,how can i fix this ?

Go here: www.radio-codes.com

If immobiliser light stays on and my renault megane 1.6 hatchback wont start whats the problem

There is a fix for this, part number D82-0544 is a CAV stop solenoid without immobiliser. (only has 1 terminal as aposed to 3) if you buy one from a local motor factor (about £15), replace it with what is on yours.
To do this, you need to find which of the 3 Black wires to take to the new single terminal.. simply turn on the ignition, find which wire now has 12v and that goes to the stop solenoid, tape the other two back. You'll never get another immobiliser issue :o)

This is going to be the fuse for the ignition live to the radio.
Basically, when fuse pops, the radio still have a perminant live from the batter, so will operate from the power button. However, it is pre-set to turn off after 20 minutes unless the power button is hit.
This is to stop you killing the battery when running the radio with the ignition off for too long, or forgetting about it.

Check the fuse for the radio, its usually a 15amp. Replace, and it should be fixed. Be aware that this fuse often takes out the power (not the light) to the cigarette lighter, and the washer jets.

Sometimes running the washer jets with an empty resevoir will also cause the fuse to blow. So make sure you keep that topped up!

M_V

there will be a combination of button presses required to reconfigure your fob to the immobiliser. you dont need to get it recoded so dont pay for it. try these:
hold the a button down for ten seconds until the light comes on constantly. then press it twice quickly and it will reprogram.
or press lock about ten times, then open ten times. this should work.
i had this problem on a rover and just pressing the buttons loads of times may allow it to be reprogrammed.
also check the battery isnt upside down in the fob.

I had the same problem with mine

your key fob is now out of sync with the ECU to sync them just follow this link (renault will charge up to £180 for new key and to sync it)

http://renaulthelp.110mb.com/ImmBypass.html

Sorry to be the bearer of bad news but im afraid you need a new radio mate.Had exactly the same problem with my renault megane and ended up going to scrap yard only cost 25 quid and that included it being decoded,been fine since then.By the way don't go to renault i rang them and they wanted 300 quid for one,taking the ****,anyway good luck.

work it manually and it should work ...ie put the key in the door and open and lock the door 3 times slowly then jump in and try to start within 15 secs .if it doesnt work then be prepared to be fleeced and lay the golden egg at the dealers

I dont know this company!!! be carefull...;)
http://www.instant-radio-code.co.uk/index.php

The code for my 2002 Megane (MK51 reg) is 5817. You use the little wheel on the steering on the right hand side of steering wheel, the one where you can change channels on your radio. This will set the numbers ie 1 2 3 4 put you first No in and press the button underneath the little wheel it will then flash onto the second No. Do the same until you get to the fourth and then hold the button in until the radio comes on. Hope this helps