The heated rear screen has suddenly stopped working in my L-reg Laguna hatch. The relay is OK and both side mirrors get warm when the button is pressed. I've metered the element and it reads (on my cheapo meter) zero ohms. If I disconnect the +ve connector and press the button I get a reading of 12V, but as soon as I re-connect it it reads 0V.
My questions are, is 0 ohms normal and assuming it is, what is the likely cause of the voltage dropping to 0 when the element is connected, bearing in mind the side mirrors get warm?
Many thanks.
Keith.
Renault Laguna Heated Rear Screen
Moderator: RichardW
[:)]
Hello
You say that there is 12volts supply at the HRW. Have you checked it this way:- Disconnect the supply connector and make sure it has battery voltage and lights up a test lamp. It must light up a test lamp as if it does not it indicates a problem on the supply side. If thats ok and an ohms test -contiunity- of the HRW is ok, ....1 Ohm sounds ok....check the earth return. Disconnect the other connector -the return- and do an ohms check to earth (car chassis) this should indicate contiunity too.
Some earth returns on the HRW are only made when the boot is shut so b aware of that when doing your checks. You can use a jump lead from from the boot catch to striker plate if needs be.
One of the most common reasons for HRW packing up is because they have been scratched although depending on the locattion of the scratch it may only knock out a bar or two of the HRW.
Good luck
[:D]
Hello
You say that there is 12volts supply at the HRW. Have you checked it this way:- Disconnect the supply connector and make sure it has battery voltage and lights up a test lamp. It must light up a test lamp as if it does not it indicates a problem on the supply side. If thats ok and an ohms test -contiunity- of the HRW is ok, ....1 Ohm sounds ok....check the earth return. Disconnect the other connector -the return- and do an ohms check to earth (car chassis) this should indicate contiunity too.
Some earth returns on the HRW are only made when the boot is shut so b aware of that when doing your checks. You can use a jump lead from from the boot catch to striker plate if needs be.
One of the most common reasons for HRW packing up is because they have been scratched although depending on the locattion of the scratch it may only knock out a bar or two of the HRW.
Good luck
[:D]