Help needed, Renault Megane not holding charge

sethsgran

Renault Megane on 54 plate.

Hi. We aim to be changing my car in the next few months so don't want to spend a fortune on it. However we have a problem that we can't solve. The car simply can't hold its charge. Admittedly it doesn't get much use but my husband feels sure it's not the battery. He thinks there is a problem with the fob, we only have one. When I lock the car it doesn't always lock and sometimes there is a high pitched beep, not too loud, for about 30 seconds after locking. There must be some electrical problem as at times the windows go up and down of their own accord.
We really don't want to spend more than £50, absolute tops as the car will probably just need to be scrapped due to the problems. Apart from putting it on a battery charger 3 times a week so I can use it the next day, what else can he do.

Marktheshark

He needs to google Renault Megane fuse box removal and connector fix.
All it will cost is his time, basically under the fuse box is multi-way connector that gets wet and mucky, the source of most electrical faults, starting issues, battery drain faults.
Once the connector is clean the issue is usually solved.

sethsgran

Fantastic, he certainly has no problem with getting his hands dirty. Thank you so much.

Strider590

If they battery is more than 3 years old, the chances are it's capacity is seriously diminished.

Unfortunately people think you can check them by measuring the voltage and this is entirely false.
It's like measuring the water level of a bucket of water with a pile of rocks in the bottom. The level seems ok, but the capacity is less than half.

Richard53

Bowing to Mark's superior knowledge as I know nothing about Meganes, but ... sounds awfully like a dead battery to me, even if your husband 'feels' that it isn't. (Why does he feel this?) If putting it on charge overnight solves the problem temporarily, that would support this view..


Also, are you sure the windows going up and down isn't just you or him pressing on the fob button for longer than usual, perhaps because the car isn't responding? A long press on my car's fob will close all the windows automatically. Just a thought.

arcon5

Yep knackered battery is very possible. What you say sounds like symptons rather than faults

sethsgran

Thanks everyone. As for windows going up and down it also happens when I am driving! I will tell him of your suggestions.

BeenThroughItAll

Disco Windows on a Megane that age is indeed indicative of water ingress to the fuse box.

angrycrow

If the windows drop when locking the car it is likely to be a fault in the temic motor control module. These sit on top of the window motor in the door. Poor design means water gets into these causing them to fail. Sometimes removing them and drying them out works for a while. Renault do not sell the temic unit on its own and will insist on a new motor.

The key cards are also notorious for failing, the transmitter coil separates from the board causing intermittent failure. There are companies that repair them for about £20 but you have to send the key away.

Marktheshark

The seal on the fusebox deteriorates and lets in water which finds its way out via the base and right in to the multi plug, poor starting, battery drain, random electrical acts, such as windows, horn, heater turning off, you name it it does it.
Cleaning out the connector and plug and cleaning the fuse box seal often fixes the issue.

Richard53

sethsgran wrote: »

Thanks everyone. As for windows going up and down it also happens when I am driving! I will tell him of your suggestions.

Ah, OK. I withdraw my suggestion.