Td5 heated windscreen and genuine switch

[kingrat]

Hi. It’s been a while.

Ok so fitted the facelift dash this weekend. Changed the fog light and hazard switches ok.

 

Heated windscreen was on a Carling on off switch. Can the genuine front screen switch be made to work with the Carling switch wiring, or would it be easier to replace with the latching rear heated window switch?

 

Thank in advance

 

Paul

[crwoody]

It depends on how it was wired with the Carling switch and whether the original timer module is still there.

The original Td5 heated windscreen wiring includes a timer relay, the switch is a momentary contact type which provides a brief input to the timer to start it and activate the heater for a short period of time. 

If there is no timer relay fitted then either type of switch would work the same but it would ideally need to be switched via a normal relay, the screen heater takes a fair bit of current and I doubt the switch contacts would last for long. 

Also it's not ideal to leave the screen heater turned on for extended periods, that's why there's a timer on the original setup.

[kingrat]

Thanks mate. From memory this has just an orange relay. I think I need to have a long look at this and work it out

[ThreePointFive]

The orange relay is the timer so that sounds promising.

There are threads on here about how to set these up with the non-latching switch, I had a bit of trouble getting mine to work but got there in the end. I'll dig out the one that I used. From what I've seen from the kits, the setup is probably identical if it's Carling or genuine but they seem to make a point of turning the relays away from the camera so you can't see which connection goes here.

[kingrat]

Yeah I found that during the weekend converted to +ve switching. Pin out is then very simple to work out. But good to confirm in the write up I found searching

 

Thank you everyone for the comments support and search. I knew PaulMc had to have written on this at some point 

Edited June 20, 2020 by kingrat