SOLVED! Just another cluster issue - RPM & MPG dead

[Torsen]

Well, the revcounter and MPG meter stopped working some time ago. I took the cluster out and checked batteries, reading 3 volts. I checked and resolder bad looking joints. Refitted and still not working. Then, I resetted service leds and now the INSPECTION light is flashing. Oh, it's an E30 318is. What sould I check next?

Help much appreciatted.

Thank you.

[Bimmerista]

My car did the same thing and it turned out to be the batteries in the SI Board.

[Eecen]

Checked your fuses?

[Torsen]

Yep, fuse #10 going strong, all other related stuff working. I think that the failure is in the cluster itself, but no clues on where to look for.

[Jean]

Next logical move would be to put another known good si board, just because batteries show 3 volts doesn't mean the board is necessarily good.

[boosted_E30]

Check fuse #12

[Torsen]

Check fuse #12

Radio, OBC, speedo working OK, not that fuse I'm afraid.

[Eecen]

Fuse 21? When my tach/econo gauge went out that fixed it. The fuse didn't look blown, but it was.

[Torsen]

I've bought a secondhand (reputedly working) cluster and the failure is still there. Now:

-I've kept my "old" coding plug. Could the problem lie there?

-How can I test the connectors? As long as fuel cons is working ok in OBC II, I understand fuel rate signal is fine.

Ideas?

Thank you.

[AndrewBird]

3V batteries should actually read ABOVE 3V if they are good (3.2-3.4 is about right). The fact that yours only read 3V probably means they are dead.

[Torsen]

SOLVED! I tried a mate's coding plug and everything works.

Thank you for your help.

[aknickintyme]

my tach/econo just stopped working this evening :(
im new to e30's ive only had mine for a week.
what is a coding plug??

[TurboJake]

my tach/econo just stopped working this evening :(
im new to e30's ive only had mine for a week.
what is a coding plug??

Coding plug is circled.
But, 99% of the time it's the SI board. especially if it just dies.

Hit your dash, that sometimes brings everything back

[Torsen]

my tach/econo just stopped working this evening :(
im new to e30's ive only had mine for a week.
what is a coding plug??

SI batteries use to fail in pre-86 cars. Joints can go wrong in any car, take the cluster out and tell us what you find :)