PDA

View Full Version : E30 M42: OBC & TACH not working


emas
08-08-2007, 07:30 PM
Hi,

Recently I wanted to find out details on each of the wires in the OBC. It has the TIME, DATE, TEMP, and MEMO. So I pulled off the harness, took the 8 wires out of the blue retainer. I had to pull on the harness wires a bit to get more play, then I head a slight snap.

Then took some measurements (measure volt, resist., etc.). When I put everything back, the TACH RPM gauge and OBC both went dead. The OBC lights up the bottons, but dead in the screen. I replaced the bulbs in the OBC, and still dead. For the TACH (RPM gauge), I pulled off the inst. cluster to see if something came loose as I heard a 'snap!' earlier. Nothing was out of ordinary there. So put it all back together for now...

The speed, temp, fuel, and lighting gauges are all working. The car drives fine. But without the OBC info, RPM reading, or Fuel Economy systems working.

Anyone have any info on this? I would greatly appreciate it. Thanks.

Emas

e30_kid89
08-08-2007, 08:17 PM
check your fuses first and go from there.

SamE30e
08-08-2007, 11:19 PM
Hmmm, odd. When my SI board went, the Temp Tach and fuel gauge both went.

roaster
08-09-2007, 04:56 PM
I have the same problem.
The speed, temp, fuel, and lighting gauges are all working. But without the OBC info, RPM reading, or Fuel Economy systems.
Few people say that its the wiring at the back of OBC.
I'm trying to get some one to take a look at it I will keep you informed, Please do the same for me when you find out the problem.

SamE30e
08-09-2007, 05:24 PM
I have the same problem.
The speed, temp, fuel, and lighting gauges are all working. But without the OBC info, RPM reading, or Fuel Economy systems.
Few people say that its the wiring at the back of OBC.
I'm trying to get some one to take a look at it I will keep you informed, Please do the same for me when you find out the problem.

My OBC is messed, the screen goes all wonky and it doesn't even work. I think its only a 6 button.

Luke318is
08-10-2007, 01:43 PM
My OBC is messed, the screen goes all wonky and it doesn't even work. I think its only a 6 button.

Does it glitch out and blink? That is the OBC itself, in my '91 it just took a hard poke to get it working......