Summer purchase - hides the winter issues....

H

HyperGrade

Member
 Peterborough
Hi Guys,

Bought my second Z in June at the peak of the summer.
Just tried the rear window heater and although the light comes on, nothing seems to be happening at the back.

Have run a quick search, but can't see anything much. Any thoughts?

TIA! :(
 
I've had a look, but can't see anything obvious. Is there a known point for wearing? The wire disappears behind that material, so it's hard to get a good look.
 
Start simple, make sure transport mode has not kicked in when a battery was changed or went flat, this shuts down non essentials like the rear screen and air-con. The fix requires re-coding.

If it's not transport mode then get a basic multimeter or 12v current tester / bulb and see if current is getting to the positive tab or elements, these will only be live with engine ignition on. If you have power there then there is probably a break in the elements.

If there is no power check the relevant fuses behind the glove box (20 & 25 according to Adamski's previous post http://www.z4-forum.com/forum/viewtopic.php?f=3&t=38888 ).

If those are good there is also a relay to check, should be marked K13 per the realoem pics. http://www.realoem.com/bmw/enUS/showparts?id=BT53-USA-07-2004-E85-BMW-Z4_30i&diagId=61_4109
Remove it and check for activation (click) when terminals 1 and 2 are energised with a 12v source, and that you have continuity using a multimeter on terminals 5 and 3 (set to ohms then meter should beep)

If that's good then it may be disconnected wire (roof out sometime maybe?) or loom damage.
 
Ok thanks- very detailed, really appreciate it!
I have no idea about Transport mode as I bought it from auction and have no history, but the A/C works.
Looks like I'll need to get some tools out and someone who knows about electrics.
Cheers!
 
HyperGrade said:
Hi Guys,
Bought my second Z in June at the peak of the summer.
Just tried the rear window heater and although the light comes on, nothing seems to be happening at the back.
Have run a quick search, but can't see anything much. Any thoughts?
Click to expand...
Did you get this sorted?

Similar story - we bought the car in summer and now discovered HRW doesn't work at all.
- Switch illuminates
- Not transport mode, as everything else works correctly
- Both fuses OK
- Continuity of circuit checked at B pillar, so appears no issues to window elements or wiring to/from window.
- But... relay was missing :? New relay from dealer fitted - makes no difference.

Any ideas?
 
Sidewaze Samm said:
HyperGrade said:
Hi Guys,
Bought my second Z in June at the peak of the summer.
Just tried the rear window heater and although the light comes on, nothing seems to be happening at the back.
Have run a quick search, but can't see anything much. Any thoughts?
Click to expand...
Did you get this sorted?

Similar story - we bought the car in summer and now discovered HRW doesn't work at all.
- Switch illuminates
- Not transport mode, as everything else works correctly
- Both fuses OK
- Continuity of circuit checked at B pillar, so appears no issues to window elements or wiring to/from window.
- But... relay was missing :? New relay from dealer fitted - makes no difference.

Any ideas?
Click to expand...
Sorry, it just cleared itself (no pun intended)
Not sure how it can go from dead to working without intervention, but it’s worked fine ever since. Best of luck!
 
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