S type 2003, heated windscreen issue

fortunately driver side works. passager side used to work intermittently, but for some reason, or just coincidence, after i changed my CCM (climate control module) i never seen the passager side work again.

i took off the A pillar and exposed the screen heater circuit plugs. unplugged both cables: no oxidation, but both flat flexcables look creased.
i took my multimeter and set it on the continuity test. placed the probes on the whindshield's plugs and there was continuity. multimeter read 250 ohms. very relieving to know the cables are not discontinued.
then i fired up the engine, i switched on the heated screen and i measured 14.x volts at the live and ground plugs.
turned off the heated screen function and 0v. turned it on again and 14.something again.
So if i have power, and the circuit works, lets see them in action: i plugged the screen cables back in, and still that half remains cold and doesnt work.... WHY ((

is the resistance reading that i get when measuring the continuity thru the screen heater circuit correct/normal?
is there another way to test this system? is there a common fault?

manny thanks



windscreen heating circuit plugs

 

i exposed the metallic flex cable to check the continuity ( i thought the white plugs were bad). today the reading was smaller 150 ohm, but it was the same both at the plugs and at the exposed metal.
i might have moved something and got a better connection? still that half doesnt work. ive seen it work last winter (intermittently), and so i am so eager to fix it.

any ideas? can someone please tell me what should the resistance reading be on a working circuit? i am avoiding to check the other side, as i dont want to have it fail.
did anyone fix this?

 

I have checked the working side.
around 1 ohm resistance.

anyone has any picrures of how the heater screen circuit looks like?

i want to see the possible weak spots thank you

 

Just Jag's Elec Guide.

 

Thank you. i mean the screen itself and the conductive material. I receive power at the plugs. Thats no issue of the car wiring.
i will check today again for oxidation or cracks

 

See figure 06.1 here:

http://www.jagrepair.com/images/Elec...al%20Guide.pdf

To check resistance of the heating elements, access relays R17 and R21 under the hood. From socket #5, you have direct access to the heater circuits. No need to remove any trim.

 

hi! ive just returned in the country after 2 months.
I used the car and both sides were working. Now that half stopped working again.
I recall the continuity measurements and the good side gets a perfect continuity value, the broken side has resistance. Most likely a broken contact somewhere.
But what can be causing these problems? Are they common ?
Thank you

 

Can you see the physical wire inside the laminated windshield? I would’ve thought that with only two connections at the windshield that it would be one continuous series run of wire to heat the entire section at once but if you’re seeing only half of it warming up that would suggest that, there are two separate parallel circuits that connect to those two connectors on the windshield. Can you see if there is a separate parallel circuit because if it’s just one series circuit, you can’t get just half of it heating up because the resistive wire would all be at the same current .

 

hi cuda! Whats good

yes, the pic i uploaded above is of the faulty side. Thing is, yesterday it worked again 🤣. Now it doesnt work. So yes: imperfect connection somewhere or workse: a crack that could discontinue the circuit in the glass.
Now i dont see any cracks in the glass that would discontinue the circuit main line, so i think its where the terminal ribbon cables join the glass main lines... The problem is i cant reach there... i could blindly if someone would have a picture of the inside of a removed screen so i could see how the glass circuit looks like

 

Well, it’s not making much sense because I looked at the schematic and there’s only one circuit two wires so it is we gotta work all or not at all.

It did kind of help me verify that I do not have a heated windshield. I took the trim panel off the right side pillar, and there’s a black connector that’s folded up in the harness, not connected to anything.

Also, odd is the fact that I didn’t see an airbag behind that cover. shouldn’t there be one there?

 

Yes those are the terminals.
now each side has its own power at least thats how it is on my 03

 

So I missread your initial post and I thought you were saying that you were only getting half of one side to defrost but you’re saying you’re only getting half of the windshield to defrost so ignore everything else I said