Lights dim and then brighten on start up.

**STI65** · 30-12-2014, 05:47 PM

My Polo has a couple of issues recently. The latest is happening upon starting it after it has been sitting for a while.
The headlights and dash lights dim and brighten and then repeat for a while until the idle seems to settle. It also has an effect on the A/C fan speed. has anyone else had this or a similar issue and what is it? Could it be that the alternator is on its way out?
Thanks for the help and advice.

**Hillbilly** · 30-12-2014, 09:47 PM

Either that or the battery

**brad** · 31-12-2014, 07:48 AM

I'd be cleaning all your battery terminals & earth connections & the connections to the big fuses / relays near the battery. Check the resistance of the cables. There are known issues if you search this sub-forum.

**STI65** · 02-01-2015, 12:16 PM

Thanks for the advice guys. I replaced the battery less than 2 years ago. If I clean it should I just use a cloth or are there particular methods and tools to use?

**Hillbilly** · 02-01-2015, 01:09 PM

You can use Baking soda dissolved in water or buy a terminal cleaner from Supercrap for $5 or so

The terminal cleaner is a double ended wire brush that has internal and external brushes that fit over the terminal and inside the clamps

**brad** · 02-01-2015, 02:11 PM

they should be shiny. wire brush & fine wet/dry sandpaper is often helpful. terminal cleaner is good but doesn't get heavy corrosion off.

2yr old battery could still be the issue

**STI65** · 02-01-2015, 04:40 PM

Had a look and the terminals look pretty clean.

**Hillbilly** · 02-01-2015, 05:04 PM

clean and tighten the earths then

**Paazuzu** · 02-01-2015, 05:04 PM

Originally Posted by brad

I'd be cleaning all your battery terminals & earth connections & the connections to the big fuses / relays near the battery. Check the resistance of the cables. There are known issues if you search this sub-forum.

+1

I would clean your earth connections as mine used to do this when it had some electrical gremlins.

**AALocksmiths** · 02-01-2015, 05:57 PM

+1 for a battery. Even though its only a couple of years old it could still be playing up, especially if there are other electrical issues like the battery being drained constantly or the alternator not charging it properly.

I think it would be worth getting the battery tested and check that the alternator is putting out enough volts. Start with that ( as you can generally get them tested for free) and then work back from there.