Hi there. Got a problem that half of the heating elements in the rear window of my 96 Xk8 Convertible work and demist fine, the other half doesn't. No obvious issues with the elements so just wondering if the feeds are from both sides and evenly split control of the elements?

Effectively looking at the back of the car from outside, starting at the bottom, elements 1,2, 4, 6 & 7 work and the others done. There are 10 in total hence my query.

any input would be great, thanks
Phil

 

first i was thinking that it could be that the defroster grid was scratched in sections causing you to have dead lines, however it looks like an overall low voltage or poor connection at the sides of the grid.

you can repair individually scratched lines with a special conductive paint that is sold for this purpose at auto supply stores. my technique for finding the bad lines is to use a small radio speaker, grounded to the car and gently rub a fanned copper wire over the lines. the noise that you hear will tell you which ones are active. do not use a test probe as any injury to the paint will make a break in the circuit.

first though i would check the voltage at the side connectors.

 

Thanks for your reply. Any idea what the voltage should be on the sides as I've finally purchased myself a voltmeter?

 

do not know, sorry. in my other cars it was always 12. disconnect the plugs to check. sometimes this can be as simple as a bad ground. Also, be very careful disconnecting the plugs as you can break the spade connectors off the glass. i have fixed this with the conductive paint that I mentioned above, but let's not invite more work.

 

Ok thanks. Will have a look at the weekend and do more checks and take the measurements.
Will keep posted.