Fuse keeps blowing - HELP!

[outrightrubix]

I've got a problem with my 08 plate Twingo. The other day the fuse (10 amp) for the interior light, boot release and rev counter blew. I replaced the fuse, turned the engine on and all work fine again...until I touched the accelerator when it blew again. I tried this a few more times with a 15 and a 20 amp fuse and the same thing happened - as soon as the accelerator goes down a fraction, it blows. I also noticed before the fuses blow, if I put my clutch down, the interior light starts to flicker.

I could live with this problem fairly easily because the rest of the car work perfectly, except it's got its MOT in 5 weeks time and will fail because the rev counter doesn't work once the fuse has blown.

Anyone seen anything like this before or got any ideas as to what it might be?

Thanks

 

[maggi200]

I've got a problem with my 08 plate Twingo. The other day the fuse (10 amp) for the interior light, boot release and rev counter blew. I replaced the fuse, turned the engine on and all work fine again...until I touched the accelerator when it blew again. I tried this a few more times with a 15 and a 20 amp fuse and the same thing happened - as soon as the accelerator goes down a fraction, it blows. I also noticed before the fuses blow, if I put my clutch down, the interior light starts to flicker.

I could live with this problem fairly easily because the rest of the car work perfectly, except it's got its MOT in 5 weeks time and will fail because the rev counter doesn't work once the fuse has blown.

Anyone seen anything like this before or got any ideas as to what it might be?

Thanks

Is the rev counter tested?

It's best to start looking, perhaps a wire is being caught when you press the pedal? I would check that and then the earths.

The lights dipping very slightly is actually reasonable as the alternator 'takes the strain' when you start to move and do things.

 

[user 980]

I'd say the same, check behind the pedal and inspect any cables to see if there's any exposed cores.

Maggi, what do you mean by is the rev counter tested?

 

[maggi200]

As in the op is concerned about his MOT regarding the lack of a working rev counter but I'm not sure it's tested? It's not standard on a lot of basic models

 

[outrightrubix]

Just checked and the rev counter isn't tested as part of the MOT which is good. Got a bit more time to sort it out. I've had a look at the accelerator pedal in the foot well. There aren't wires behind it and it appears to go straight into a black box which looks more electrical than mechanical so I can't see how any wires would be being trapped - I don't know much about cars though.

 

[maggi200]

That's because there's no throttle cable.

And I suggested it in case something had moved. Where are you, perhaps a friendly local might help with a suggestion or a nosey

 

[singlespeed]

changing the fuse to a higher rating is asking for trouble. The fuses will be chosen for the maximum system loading, so guestimating about 110Watts of power from a slightly flat battery

If your blowing a 20 amp fuse whilst the battery and alternator are charging properly (+13volts), theres somewhere above 260Watts of power being used/earthed.

If it happens when you press the throttle, it kind of points towards the throttle control circuit... However, it may be a wire or component further away from the peddle position sensor which is just above the peddle.

As a rule of thumb, if you have done or had any work done recently, look around there first, even if you think its not quite related.

 

[benmc]

Check loose connections on rev counter maybe disconnect it them try it if it pops again its not rev counter be easy one to do ..

 

[Martin_172]

Stick a jump lead from negative battery terminal to the engine block to add an extra earth point and rule out anymajor earth straps being broken, just cured a non starting 172 that was doing stupid electrical issues by doing this, it was the earth strap from gearbox to body that was broken

Also had issues with interior lights and dials on mk2 clios with trapped wires or dodgey bulbs on rear lights.

Standard stereo system on ur car??