My tach only works in the mornings

[kronus]

Yup. Seriously. Going to work in the morning (~8:15 am, 50F outside), it works fine. Coming back from work, (7:30pm, ~50F outside), it does not work. This is consistent behavior over two weeks. Before I pull the cluster and resolder everything, has anyone heard of this happening? I'm fairly certain that this is completely impossible, yet it is happening.

Econometer continues to work regardless of time of day, by the way.

[Varinn]

What do you do for work?

Are you a telemarketer?

[lolcantturn]

A politician perhaps?

[kronus]

lol, no.

[selturk]

Same here.. Econometer works but my tach works randomly whenever it feels like working :(
Can it be the SI batteries?

[Matt-B]

dont drive at night

[b*saint]

Why do you need a tach?

[chadthestampede]

only in da mownin

[StereoInstaller1]

Get a tach that works all the time

[Adrian_Visser]

Broken solder joints on the circuit board which open and close depending on the temperature of the circuit board material, re-flowing the solder might fix it if you are lucky enough to find where the cracks are.

[Jean]

^ exactly. I just did this on 3 clusters (take it all apart, reflow every contact on the board), one actually had a main board from 2004!!! That went straight into my car hehe.

[Bimmerista]

Had a similar, only my tach worked when the weather was cold.

Turned out to be the SI board

[Adrian_Visser]

On a side note whenever my tach and speedo are reluctant to work in the cold a quick judo chop to the instrument cluster wakes them up everytime.

[evil_twin]

Get this

[selturk]

so did you figure out what was wrong..?

my tach stays at 2,5 when I start the car and it doesn't move up or down.