Hello,

Having trouble with the heated screen in my mk3 mondeo.

There seems to be no power at all. Idle doesn't drop when it is switched on, nor does the light on the switch coming on.

Things I've checked...

Heated screen is fitted.
Connectors under the scuttle are tight and secure
A GEMS test notifies it is getting a signal when the button is pressed.
Fuses 2x30A and 1x3A are both fine.
Relay is fine.

Any ideas?

Cheers

 

Contenuity the screen connections
make sure screen is ok first

 

what shape mondeo is it?

 

mk3 mondeo brian

if the gem sees there is power there, remember that you need to have the engine running for it to come on first

once it's on check the wires to see that there is power going through them

most likely cause is the connectors at the bottom of the screen going fuzzy and not letting any power through, but you have obviously checked that these work and that the wires haven't chaffed through ont he bonnet and stuff yes?

 

is an 03 plate for example classed as mk3? (i tend to identify the model by the screen part number. probably sad i know). if so, check all the wires where they connect into the screen as they are very flimsy. if you didnt know there is a wire that goes under the outer 'a' post trims and connects at the top. they are that flimsy i have broke a few off simply removing the tape used to protect them in transit from the manufacturer

 

I'll have a another good look tomorrow. The strangest thing is that the light on the switch is not working, yet the switch is fine.

I'll have a look tomorrow, do you mean under the plastics that run up the side of the windscreen Brian?

Dojj, the wires have not chaffed as far as I can see.

 

yeah thats the one. as for the light on the switch, i have put non heated screens into cars when they should of been heated into the first shape mondeos and also on focus' andthat wouldnt bring on the light on the button as the circuit wasnt complete. its probably the same on other ford models so it would suggest the elements are fubar. one possible way to check would be disconnecting the screen and bridging the harness and see if the switch lights up

 

put an resistance meter across the screen. it should be less than 0.5 ohms. or use a current meter to see what is going on! also need to check relays, you will feel them click as they switch the power circuit also check for earthing faults on the edge around the screen