strange problem with bmw

yesterday i stripped and re-tinted a rear screen on a 1999 bmw 5 series saloon (sedan for our american friends), everything in car worked fine before i started, now that screen is re-tinted the heated rear screen works fine on its own and the fm aerial works fine on its own, BUT..... when i have the radio on and then turn on the heated rear screen i lose fm reception????????? very wierd, never had this problem before, bmw are one of my biggest customers and i tint more bm's than i do anything else and ive never had this happen before (im sure dealer would be on the phone if this was occuring) i have checked all screen connections they seem fine, i have checked the dual diversity units at the sides of the screen both seem dry and all connections to them seem tight and wiggling them with radio and rear heater on doesnt yield any clues, i cant get my head round this one at all, any help much appreciated

btw- its johnson greystone film which is non metalised, and also exactly the same as what was on it originally as i tinted the car in the first place

not only the defrosters on the rear glass, but antennas also. some metal films conduct between the defroster line causing signal failure. also the brain to the radio is in the trunk and should always be covered to prevent the water from running down and shorting brain. these 2 things are your possible problems.

yes thats correct, antennas are in both top corners of the screen, clearly visible as seperate from heater, as im using a non metalised film i dont think that the film is the problem also its the same type of film that has been on the car for the last year or so, i dont even keep metalised film in my shop, non-metalised only for me. the "brains" for the antenna aka "diversity units" on this model are located at the side of the screen clearly visible with trim removed, these units are dry and should have at no point been wet during install as they were covered in polythene, you can easily trace the wires from these units to screen/aerials etc and see which wires do what, as i said i have checked all connections etc and given them the wiggle test all to no avail, but thanks for your ideas

...who says it wasnt working befor you did the job, did you check it first???

unfortunately in this case this is my own car, i know it was working beforehand, thank f@#k its not a customers car cause it looks like in needs a new backglass

Yeh, the problem is you are using metalized film on the rear glass. Try a color stable dyed film and the problem will magically disappear.

Let it dry a while longer, maybe it's the moisture left over that's conducting...

Why dont you get a regular antenna and plug it in and see if it still does it? heck if its your car and it works, just hide it under the dash. I know its ghetto but better than buying a glass.

WETINTCARS.COM if you read both my posts - I AM NOT USING METALISED FILM (but thanks for trying to help) johnson greystone was developed purely to be 100% antenna safe, the car has had greystone on it for over a year, problem has only arisen since strip an re tint, i have been doing a bit of research on the net and apparently if there is a slight break in the heater it arcs this causes interferance on fm, nightmare!! actually seems to be quite common even on non tinted cars, its getting a new bg 2moro i cant handle my own car not being right

my thoughts exactly

blade, yes this was my original thought, the wierd thing is the dryer the window gets the worse the problem gets, im pretty sure its fully dry now as i left an IR lamp on it for a while today, its been tinted for about 3 days now, looks like is def a new bg

I would have gotten a window mount antenna and stuck it up in the black on the back window where you can't see it,,,$40 beats a new window
http://www.ecshylites.com/page/page/761353.htm

yeh i thought about that 2, my experience with the glass mounted aeriels is that they are rubbish, i dont know about in the states but over here their reception tends to be substandard, new bg should sort it out and luckily its quite a cheap replacement

good deal man. Yeah I have seen mixed reviews with those antennas. Good luck with the new window.

i got my new bg today, its sitting in the w/shop tinted ready to be fitted 2moro, so i decided to have a little experiment with the old one, i tried the cut above topline of heater, i just cut thru the 2 verticals as the window is coming out anyway, this made no difference to problem, i then removed thefilm over the aerials, again nothing, worth a try tho for future reference, so 2moro we find out if the new bg solves it

well thats the new bg fitted, problem solved!!

....it was fukd then mate

it seems so, like i say thats everything working fine now with the new bg, will be wary of that in future

stareo shops carry antenna adapters and you might be able to hide a differnt anntena in the headliner...not sure if you solved the issue yet? this would be the next avenue before bg replacement. might even enhance the radio to pick up more stations, this has been done in my shop for a different reason though...

new screen is aleady fitted but thanks anyway, it was actually quite a cheap window

I blame it on the metalized films you use hahahahahaha

Hows the car drivin Scott??

fantastic!! its like a different car, got a bg fitted for £90 so thats another problem solved