Switch Dimming

[DradusContact]

I have a problem with my rear demister. When i put it on with the lights on, it dimms quite a bit. It gets even worse if i use more electrical power, like putting the indicators on. I have a dummy front fog light switch running of the voltage of the switch next to it. Could this be causing it?

 

[Cherie]

You mean your headlights dim when you switch the demister on? That's pretty normal, as the demister does draw a lot of power. However, if everything is having the same effect, it could be a problem.

However, i'm not sure at the moment what it could be, I'll see what I can find out.

 

[Dal]

Does the engine slow down just a tad as well? That's normal when under lots of electronical (<<good word eh?) load.

 

[DradusContact]

Yes the engine does slow a tiny bit. But thats not what worries me. Its the way the demister light dims if any other electrical current is used, like the indicators. You know when you see old escorts and the brake lights dim when the have the indicators on? I dont want it to be like that. As far as i can tell its only the one switch that does it. The guy who converted my switches to blue might have used led's that are a bit too bright maybe? Or beacuse im running the fog light switch off the switch next to it maybe? Something to do with parallel circuits i seem to remember from my science days at school.

 

[Dal]

Check the earthing points perhaps?

 

[DradusContact]

inkeye:

( couldnt find a better emoticion to show me with that going right over my head! )

 

[BOK]

Your battery could be on the way out.

 

[benking]

Mine dims, i have a sub and a dvd player so it draws more power from the battery than what it was designed for. If you have any aftermarket equipment i.e stereo, sat nav, etc it will draw more power from the battery. Any alteration or add on in anything electric can draw more power hense a lack of power in other areas to cope. Try testng the battery or as colin says replace it

 

[DradusContact]

Battery is a super-dooper one only 11 months into a 4 year guarantee. Its not the battery. It only happens with the one switch.

 

[BOK]

You've probably got a charging/voltage regulator problem then...maybe try a good used alternator.

Does it sound like you have a belt slipping?

 

[DradusContact]

The belts squeak like mad when its cold. Once its warmed up they sound fine. Its never given me cause for concern, i assumed it was just moisture collecting on them.