1987 325i convertible. Tach, mpg, and temp gauge (reads cold when warm) don’t work. OBC computer is dark but otherwise works. Service indicator lights work. I replaced the batteries on the SI board and they test ok. Fuses 10, 12, 21 are ok. What should I check next?
your SI board batteries sound like they've had it. cluster will have to be removed and batteries replaced, or the board will have to be sent off to bavrest or other electronic restoration company to be fixed.
try another cluster. the circuit board has likely failed.
edit : make sure the coding plug is seated proper.
Last edited by 82eye; 05-04-2023 at 01:42 AM.
Makes sense. Unfortunately I don’t have a spare.
- - - Updated - - -
Makes sense. Unfortunately I don’t have a spare.
see if you can source a spare or test before sending it off / going further.
download a copy of your etm to trace the electrical from here : Index of /Manuals/BMW (wedophones.com)
get one before gone. you can trace all the inputs and fail points etc.
I have to hit the top of my dash like the fonz every drive to get it to get off cold...also my tack and speedo didn't work for a year of driving and after I drove the car more and more they just started working. Don't know if that's a solution, but might give you hope.
FE548433-01BD-4827-90E1-17967551B651.jpg
Hopefully this picture uploads. I found a spot on the service indicator circuit board that was damaged. One of the screws that holds the two cluster pieces together was screwed in too far. Is that my issue?
That is your issue for the tach and mpg as they are both driven from the SI board. The wrong screw was used. This kind of damage is not uncommon. Your temp gauge is likely the ground nut on the back where it attaches to the main board. Snug those and the fuel gauge ones up before you reinstall the cluster.
Also read this tech article https://bavrest.com/technical-articles.html
"Howdy, Folks!"
1986 Delphin 528e - Roof rack equipped lumber hauler.
1989 Zinnoberrot 325iX Sedan - I miss this car. (Deceased)
1998 Avus Blau 328iC - Someone else's project now
2008 Platinum-Beige X3 3.0si - Current project
2012 Alpine White X3 xDrive35i - My new snowmobile.
2020 Estoril Blue 440i xDrive cabrio - This car is a blast to drive.
"Howdy, Folks!"
1986 Delphin 528e - Roof rack equipped lumber hauler.
1989 Zinnoberrot 325iX Sedan - I miss this car. (Deceased)
1998 Avus Blau 328iC - Someone else's project now
2008 Platinum-Beige X3 3.0si - Current project
2012 Alpine White X3 xDrive35i - My new snowmobile.
2020 Estoril Blue 440i xDrive cabrio - This car is a blast to drive.
You could theoretically clean up those 2 damaged traces and bridge them each over with wire, thus restoring their connectivity. Specialty electronics repair shops may be willing to take on the repair for a reasonable price. I've seen similar repairs done in handheld electronics and game consoles.
- - - Updated - - -
I actually have a spare cluster and am in Kansas City also, if you wanted to buy one. Do you have an e or i?
If you're looking at having someone else do a repair/replace of the SI board, I'd suggest contacting https://bavrest.com/si-boards.html
"Howdy, Folks!"
1986 Delphin 528e - Roof rack equipped lumber hauler.
1989 Zinnoberrot 325iX Sedan - I miss this car. (Deceased)
1998 Avus Blau 328iC - Someone else's project now
2008 Platinum-Beige X3 3.0si - Current project
2012 Alpine White X3 xDrive35i - My new snowmobile.
2020 Estoril Blue 440i xDrive cabrio - This car is a blast to drive.
Bookmarks