MK5 Golf GTI

All Things Mk5 => Modifications & Technical Area => Cosmetic/Interior Modifications => Topic started by: Garth on April 18, 2010, 03:00:44 pm

Title: Any auto electricians on here?
Post by: Garth on April 18, 2010, 03:00:44 pm

I need to wire something up with a relay and wanted some advice before I start...

I currently have something fed with a live from the light switch so that it varies the voltage with the interior light dimmer. Now I want to continue using this but also introduce a relay so that when the lights are off, I get a 12v supply, but when the lights are on, I want the variable voltage I currently use.

This is a pretty simple circuit and I can find the necessary feeds, I just need to know what kind of realy will be suitable for this and any advice on wiring it up if necessary.

Thanks  :drinking:

Title: Re: Any auto electricians on here?
Post by: cameluk on April 18, 2010, 09:54:25 pm

A simple SPDT relay should do

connect the NC pin to 12V
connect the NO pin to the dimmed voltage
connect the common pin to the device you want controlled
connect one side of the coil to ground, and the other side to 12V controlled from the light switch

Maplin do a suitable relay N00AW

Title: Re: Any auto electricians on here?
Post by: Garth on April 19, 2010, 09:52:08 am

Nice one, thanks mate you're a star  :drinking:

Title: Re: Any auto electricians on here?
Post by: Garth on April 24, 2010, 07:57:33 pm

Camel,

I'm afraid I'm being thick. I've got the relay now, but your instructions don't help much when I don't know which pin is which  :ashamed:

Can you tell me which pin connects to what as per your description before please? I've attached a photo of the relay showing the circuit diagram. The pins are just numbered.

Thanks a bunch  :happy2:
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fss335%2Fgarthfred%2Frelay.jpg&hash=5f6010dc118cabcf8266405333300d3ebe85ec1f)

Title: Re: Any auto electricians on here?
Post by: Garth on April 24, 2010, 08:11:43 pm

I reckon I've worked it out:

85 : Ground
86 : Ignition switched live
87 : Dimmed 12V
87a: 12V
30 : Load

Correct?

Title: Re: Any auto electricians on here?
Post by: cameluk on April 24, 2010, 11:15:53 pm

Spot on   :smiley:

Title: Re: Any auto electricians on here?
Post by: Garth on April 24, 2010, 11:38:56 pm

Yessss! I'm not an idiot after all  :grin: