14 replies to this topic

[Dirk130]

Model: mini cooper
Year:1991
Description of problem (please be as in depth as possible):

how to connect a heated front windscreen

Any non-standard parts that might be involved with the problem?

my idea:
12 v from fusebox with to a switch, a xtra in line fuse for back up, to the screen, earth from the screen and the switch to a point on the bulkhead or other point at the body

anything else i may forgot about???

Edited by Dirk130, 12 December 2009 - 10:35 PM.

[Dirk130]

picture/paint drawing

[Ethel]

You could pretty much copy the rear heated screen. Use the same gauge wire and switch that's up to handling the current. a warning lamp would be handy too.

[Dan]

A heated front screen draws too much power to be run on any existing circuit. You should run in a new circuit from the solenoid, including a fuse. You would be best to power it through a relay controlled by a switch on the ignition live circuit. Preferably that would be a timer relay and a momentary switch so that it can't be left running. The earth just runs to earth, not to the switch. Incidentally putting fuses in series with each other as you suggested is bad practise electrically speaking.

[adam_93rio]

wouldnt you just see the strips of the heated screen all the time tho, not like modern cars where you cant see it

i thought the same about the power itll take

as said, youll have to have a separate fuse, and a relay powered by the switch.

not sure of the amount that one draws, but its basically high resistance cable (isnt it?) so draws a lot
i wouldnt want to risk leaving it on by accident. its one thing being steamed up or frosted up on cold mornings, but its another thing sat in your car on a cold morning for longer because the car wont start

[Dirk130]

so if i understand you correctly it would be like this:

Edited by Dirk130, 13 December 2009 - 09:08 AM.

[Dirk130]

i think it would draw the same amount of power as a rear heated windscreen?? as far as i know the rear window isn't connected up by a relay

[MRA]

A heated front screen on a Mini takes anywhere between 20 & 40 Amperes, so you will need to fit a relay. Rear screens by comparison take less then a third of the current to run them. So don't be tempted to run straight off a switch as most can only operate at upto 10A and a thermal event is no fun at 60mph on a cold frosty morning

[Ethel]

Heated switch would go nicely with a heated screen.

Minspares say the front screen is rated at 15amps, but that is a fair chunk to add to an existing circuit. A relay would allow you to take a feed off the solenoid but make it ignition dependent - and run it off the same switch as the rear screen.

You can get invisible front heated screens for Minis, not as good for the retro rally look though.

[mk1leg]

I installed mine with a relay and have had no problems...............

[DannyTip]

Mine's fitted but not wired in yet. I was planning on using a relay as suggested above using a switched live for the switch side so it can't be left on when the engines not running.

[Brams96]

Dirk130 - that is close with the wiring but i would do it like this.

[Dirk130]

Dirk130 - that is close with the wiring but i would do it like this.

Thanks

electrics is not my favo thing

[MRA]

make sure that the wiring is capable of carry the current plus a safety factor.... and that the fuse is lower rateing than the wire (the fuse protects the wiring and nothing else) you could use switched earth instead of switched live but really you can get relay's than can carry the current so it's not an issue like it used to be

Go for a full iso relay of at least 30 Amp rating, 2.5mm automotive wire....... with wiring if it is not good enough it will only get worse so think long term and ensure that all joints are crimped using the correct tooling, I use heat shrink with glue lining to seal (paint hot air stripper will do the shrinking)

[Pooky]

a thermal event is no fun at 60mph