On Board Computer Power Issue? 1999 Z3 2.8

[Dbirwin]

Greetings All

I am the new owner of a very clean 1999 Z3 2.8 with 67,000 km bought from a friend who has owned it from new.

Two very minor issues which appear to be power related however in both cases the fuses appear to be fine.
1. On Board Computer is blank. The previous owner recalls it to be operational.
2. The side view mirrors to not appear to work via the switch in the drivers door.
I have recently had some work done on the car to certify it to local standards and address issues related to lack of use, brakes, calipers, rotors, coils, plugs etc. Some sensors and bushings.

Aside from fuses is there anything else I should be checking as the root of the problem. A common cause?

Help and insight welcome.

 

[t-tony]

If the car has been standing for a long time and the mirror switches not used then I would remove the switch and give it a liberal dose of electrical contact cleaner while operating the switch and see what happens. Do the seat motors all work ok? These can be an issue when they have not been operated over a long spell.

Tony.

 

[Dbirwin]

If the car has been standing for a long time and the mirror switches not used then I would remove the switch and give it a liberal dose of electrical contact cleaner while operating the switch and see what happens. Do the seat motors all work ok? These can be an issue when they have not been operated over a long spell.

Tony.

Hi Tony. Seats work perfectly. Tires may have a few flat spots but other than these two small issues the car is magnificent.

 

[D R Oldfield]

Hi 1998 2.8 computer died when it was laid up for 12 month the display would only show four lines down the middle i had to replace it with a second hand one

 

[NZ00Z3]

Have you downloaded the wiring diagrams for your car yet? There are 6 North American versions that cover the production run for the Z3. Find your build date (month/year), then checkout the "Resources" section of this forum. In the blue bar right at the top of the page. On the second page you will find the wiring diagrams. The date range that they apply to is on the front page of each set of diagrams, bottom right.

 

[Dbirwin]

Thanks for the input. Hopefully the OBC is not dead. I will access the diagrams and read the entrails. I am sure a flurry of questions will follow.

 

[Kevin z]

If the car has been standing for a long time and the mirror switches not used then I would remove the switch and give it a liberal dose of electrical contact cleaner while operating the switch and see what happens. Do the seat motors all work ok? These can be an issue when they have not been operated over a long spell.

Tony.

Remove the computer and unplug it from rear allow 24 hours to mother warm and plug it back on it should resert

 

[Kevin z]

Sorry bad typing

 

[Dbirwin]

Sorry bad typing

Thanks. It’s freezing here in Ontario. May give it a try when it warms up a bit.

 

[Kevin z]

Thanks. It’s freezing here in Ontario. May give it a try when it warms up a bit.

 

[andyglym]

Ref the mirrors, it could be the case that the mirror wires have not been reconnected when removed at some point.

 

[Mint]

Holy thread ressurection BatMan. The OP hasn't been on the forum for over a year. I don't think we'll hear what the solution was

 

[Fender2004]

The wing mirror could be a defective motor?

 

[e30cabrio]

I replaced my interior with one from a Z3M, no OBC, I did not care, I'm needing AC since I live next door to the surface of the sun in Phoenix & the clutch is not engaging. I saw it wanted ambient and since I removed the OBC thought that may be connected so I reconnected it and it is blank.

It is 97 right now & has not been under 70 for some time, is that still a possibility (that it needs time to "readjust" I checked the fuses they are fine & it was working before it came out.

I also have odd outside mirror issues, sometimes they don't work with the door closed. I have replaced the switch & the same sporadic issue occurs, they work all the time with the driver door open.

I just sprayed contact cleaner into both sides, it lights up from the headlight switch. Nothing else though.

 

[e30cabrio]

I did not get the OBC working but I did get the AC back, There is a small hidden connector for the AC clutch that disconnected I guess when the compressor was hanging when the motor came out. I reconnected it & I have AC, OBC is back in the drawer.