I have a 2003 BMW Z4 2.5i Sport. About a year and a half ago, I started having some electrical issues, most of which have gotten worse. I can't remember the exact progression of these things, but some of them started before others, though all began within a two month period. The top doesn't go up or down (red lights don't even come on anymore when the button is pressed), the windows don't go up or down (unless operated with the key in the door), the key fob intermittently will not operate the locks or trunk release, the A/C only works sometimes if the A/C was turned on before shutting the car off and starting the car again, the instrument cluster looks like a Christmas tree, the turn signal indicators don't light up (exterior signals do flash though), high beam indicator doesn't light up (high beams work), the battery drains while the car is off, the dash lights stay on when the car is shut off (probably the cause of the battery drain), the dash light dimmer is non-functional and the CD player reads <Disabled>. When the car is first started, the dash lights shut off and it takes around two minutes for them to come back on, but then do not turn back off when the car is shut off. I've installed a negative terminal switch in the trunk that I've been using every time I drive the car to avoid the battery drain since the issue began.
One thing that I've tried recently, after reading a little about people having similar issues, is replacing the relays in the GM5 module. This probably wasn't a good place to start, but like I said, I'm a little lost as to where to look next. Unfortunately, after replacing the relays, the car is starting intermittently. I'm not sure how this affected it, as I read that the car should run fine even with the module removed from the car, but my guess is that something related to the electrical issues I've been having worsened with the GM5 module removed. The relay swap went reasonably well and when I put the module back in, the door locks are functioning fine (which they did before I changed the relays as well), however the car doesn't want to start 3/4 of the time when the key is turned.
I feel like I need to start by chasing down the culprit of the electrical issue. I think that the two issues are probably related, but I need to start somewhere. It's possible that they aren't, but if I can fix the electrical issue with the car off, that at least gives me a starting point.
Right before these issues began, I installed coilovers and threw new 19" wheels on the car. If I didn't have so much money invested in it, this issue has gotten out of control enough that I might even consider having to sell the car. I've really loved my Z4 for the 6 years that I've owned it though, and really hope that someone can offer me some sort of advice to help get the car back into shape before the summer.
Thanks in advance for any advice that anyone can offer!
One thing that I've tried recently, after reading a little about people having similar issues, is replacing the relays in the GM5 module. This probably wasn't a good place to start, but like I said, I'm a little lost as to where to look next. Unfortunately, after replacing the relays, the car is starting intermittently. I'm not sure how this affected it, as I read that the car should run fine even with the module removed from the car, but my guess is that something related to the electrical issues I've been having worsened with the GM5 module removed. The relay swap went reasonably well and when I put the module back in, the door locks are functioning fine (which they did before I changed the relays as well), however the car doesn't want to start 3/4 of the time when the key is turned.
I feel like I need to start by chasing down the culprit of the electrical issue. I think that the two issues are probably related, but I need to start somewhere. It's possible that they aren't, but if I can fix the electrical issue with the car off, that at least gives me a starting point.
Right before these issues began, I installed coilovers and threw new 19" wheels on the car. If I didn't have so much money invested in it, this issue has gotten out of control enough that I might even consider having to sell the car. I've really loved my Z4 for the 6 years that I've owned it though, and really hope that someone can offer me some sort of advice to help get the car back into shape before the summer.
Thanks in advance for any advice that anyone can offer!
