Electrical Nightmare

BimBim2oo2 · Post by **BimBim2oo2** » Thu Aug 02, 2012 9:45 pm

My recently acquired 81 528 is turning into a big PITA. The majority of my issues are electrical. Some of the problems I'm experiencing are:

ODO IN OP
Speedo IN OP
Tach IN OP
Fuel Gauge IN OP
High Beams IN OP
Heater is stuck ON
Hazards recently turned on randomly killing my battery (found the culprit hopefully believe it was a BMW Relay 1 364 654- this relay was making very loud clicky noises which leads me to believe its done)
Rear passenger side window IN OP- I believe this to be a faulty motor and another member is sending me a good one to test it out. All other windows work
Sunroof just went IN OP
Also I noticed that when the above mentioned relay went bad my temp gauge suddenly was reading hot. Is this something that would be related to the relay?

Im sure I'm missing a few but this is what comes off the top of my head.

So my question is: Has anyone else experienced similar problems? Im trying to find a good place to start in tackling this. Im a bit new to the electrical realm of cars however I do have experience in electronics so it shouldn't be anything to difficult for me to handle with a little guidance.

Thanks for any help guys

Josh

themilkguy · Post by **themilkguy** » Thu Aug 02, 2012 10:04 pm

Josh,

I am by no means a BMW electrics dude, but I do have a couple of suggestions based solely on toilet bowl spirals I have encountered in airplanes.

That many separate systems going awry at once suggests (to me) that it is more likely a bad ground or a bad power source. I don't know if the 528 is structured exactly like my 520, but my wiring harness comes in at the top of the driver's side of the firewall and splits into almost a half dozen multi-pin plugs, all attached to a metal box/housing. I'd suggest starting there, especially if new systems are failing. From there, move to check the common ground for the dash systems.

G'luck,
Craig

BimBim2oo2 · Post by **BimBim2oo2** » Thu Aug 02, 2012 10:12 pm

themilkguy wrote:Josh,

I am by no means a BMW electrics dude, but I do have a couple of suggestions based solely on toilet bowl spirals I have encountered in airplanes.

That many separate systems going awry at once suggests (to me) that it is more likely a bad ground or a bad power source. I don't know if the 528 is structured exactly like my 520, but my wiring harness comes in at the top of the driver's side of the firewall and splits into almost a half dozen multi-pin plugs, all attached to a metal box/housing. I'd suggest starting there, especially if new systems are failing. From there, move to check the common ground for the dash systems.

G'luck,
Craig

I will start there. Friday I will be spending the day doing suspension and sat is going to be dedicated to getting this figured out. Right now I'm just trying to get a game plan figured out. I know that sounds corny but from past experiences in other projects it helps to know where you want to start and where you wish to finish.

Also the ground idea somewhat makes sense. I know the PO had the motor out before it was sold. So there is a possibility that certain connections were not connected or connected properly

Does anyone have a PDF of a schematic or know where I could source one from?

Mike W. · Post by **Mike W.** » Thu Aug 02, 2012 10:13 pm

Just making sure, it is an E12 528i, not an E28 528e, right? Because the answers are very different.

Speedo/odo is driven by a cable off the transmission, thru a box on the frame rail, up to the speedo head. Purely mechanical.

Tach/etc, pull the cluster and make sure everythings plugged in.

Hazards. The switch is a common failure and usually repairable, see the FAQ's.

Rear window inop. I've had problems with the stop compacting and the window getting locked in position. Loosen things up and see if it works.

Also I noticed that when the above mentioned relay went bad my temp gauge suddenly was reading hot. Is this something that would be related to the relay?

That's a bad ground. Check the battery to body ground and run an extra one if necessary between the engine and the body.

BimBim2oo2 · Post by **BimBim2oo2** » Fri Aug 03, 2012 7:46 am

Mike W. wrote:Just making sure, it is an E12 528i, not an E28 528e, right? Because the answers are very different.

Speedo/odo is driven by a cable off the transmission, thru a box on the frame rail, up to the speedo head. Purely mechanical.

Tach/etc, pull the cluster and make sure everythings plugged in.

Hazards. The switch is a common failure and usually repairable, see the FAQ's.

Rear window inop. I've had problems with the stop compacting and the window getting locked in position. Loosen things up and see if it works.

Also I noticed that when the above mentioned relay went bad my temp gauge suddenly was reading hot. Is this something that would be related to the relay?
That's a bad ground. Check the battery to body ground and run an extra one if necessary between the engine and the body.

Thanks

The car is a E12. Ive already printed out the DIY dash removal and will be getting on that starting tomorrow morning. Ill double check the ground from battery to body.

Falkenberg · Post by **Falkenberg** » Mon Jan 07, 2013 7:35 am

themilkguy wrote:Josh,
check the common ground for the dash systems.
Craig

I'm starting to see some ground problems in the dash, temp gauge goes up and down when turn indicators function etc. I've removed the kickpanel on the drivers side, but I could not see any ground to body there. Do you have any idea where it is? I hope I can fix it without removing the dash.

themilkguy · Post by **themilkguy** » Mon Jan 07, 2013 9:00 am

I'll have a look this afternoon and if I can lay eyes on it I'll get a picture. My dash is... in my basement.

BimBim2oo2 · Post by **BimBim2oo2** » Mon Jan 07, 2013 2:38 pm

I got it all worked out and everything is working properly. Turned out to be flasher relay and the hazard button. Sorry I havent updated this.

wkohler · Post by **wkohler** » Mon Jan 07, 2013 10:43 pm

Most likely the switch fried the relay. I wonder how big of an issue this is for M1 owners.

themilkguy · Post by **themilkguy** » Wed Jan 09, 2013 6:55 pm

Falkenberg wrote:I'm starting to see some ground problems in the dash, temp gauge goes up and down when turn indicators function etc. I've removed the kickpanel on the drivers side, but I could not see any ground to body there. Do you have any idea where it is? I hope I can fix it without removing the dash.

I haven't forgotten about this - I braved the cold with a flashlight last night trying to find evidence but all I could find for certain was the group ground under the fusebox. That's not to say there aren't more, I just haven't found them.

I will say I imagine your US E12's are wired differently, though. I have Group Solder points as well as Group Grounds showing on my Schematic. I'll keep looking.

Do you have a schematic for your model? I may have one I can scan if not.

Cheers

BimBim2oo2 · Post by **BimBim2oo2** » Wed Jan 09, 2013 9:14 pm

More electrical issues for my car. Swapped my gauge cluster today now my temp, fuel gauge are in op as well as my windows. Im thinking its my combo relay (again) going to test it tomorrow. I couldnt see any lose grounds or anything out of the ordinary.

Mike W. · Post by **Mike W.** » Thu Jan 10, 2013 12:03 am

If you have cluster issues after swapping the cluster, it's probably the problem, or at least the connections to it. Work it part by part. On the windows I'm guessing you still have the kick panel off below the steering column that has the circuit breakers for the windows in it. And you have them unplugged.

BimBim2oo2 · Post by **BimBim2oo2** » Thu Jan 10, 2013 8:15 am

Mike W. wrote:If you have cluster issues after swapping the cluster, it's probably the problem, or at least the connections to it. Work it part by part. On the windows I'm guessing you still have the kick panel off below the steering column that has the circuit breakers for the windows in it. And you have them unplugged.

Swapped the old cluster back in and same issue. Temp and fuel gauge were both working prior to the cluster swap. I was careful when I pulled the old cluster out. As far as the circuit breakers are concerned I have them connected. I pulled the cluster out and searched in there for a few mins looking for any loose grounds/wires and found nothing. Ive had this issue in the past before and it came out to be a bad relay so im pulling the relay today and going to test it. As far as the windows are concerned I really have no idea. Im hopeing that they are also tied into the relay that or the circut breakers are bad. Hopefully I can get this all sorted today not holding my breath though.

Just checked all the relays all tested good. Now I am lost with this issue