Tacho not working

[Error404]

Thanks guys. This is a 7A Johne
I really need to put some more fuel in it and run it up to temperature to check the fuel and temp guages work too. The oil pressure guage has stopped working too - it jumps to 2 bar once you turn on the ignition (engine not running). Stays at 2 bar with the engine running - not a flicker.

I have already tried another set of clocks which was working fine the last time i used them, everything else except the tacho seems to work fine so would be a strange coincidence if both tachos had failed.

The thing with the oil pressure warning is what is making me think there is something missing here. Red autocheck oil pressure warning triggers during the pre-start check, without the engine running. It then stays on constantly with the engine running (I've tested oil pressure mechanically which is fine)

So there is definitely no control relay? Seems odd that I have a spare relay plate

Would I be able to detect the ECU pulse using a multimeter or anything else?

Thanks for your help
Alex

[Error404]

Ok just been out to check on a few things; the autocheck bulb monitor is also triggering with the ignition on, even though all the bulbs work except the number plate lights (but don't think these are on the same circuit?) Could this have something to do with the other problems? Cant remember ever havng a problem this frustrating before

[twoqu]

Have you checked all the fuses. Some odd things are bundled together.
Often when poking about you blow one.

[Error404]

yeah check all the fuses about a dozen times

[twoqu]

Well if the rear number plate lights worked before, perhaps thats a clue!
Depends what you disturbed. Perhaps you have mistakenly swopped a connector with another.
Not sure on the 7A but according to Mike's list the rear number plate light is fed from the same fuse as the instrument cluster illumination!
Alternatively you might have to undo what you did and see what the results are I guess.

[Error404]

Cheers
My dash lights and interior lights work fine.
I installed electric seats, but all i did was add an earth and plug a 30a feed into the fuse board and fit a couple thermal fuses into the aux relay panel. Checked all the earths and all appears fine and nothing missed
All the plugs there are colour coded so not sure they can go back the wrong way?

Sure its something simple but I have checked eveything that seems logical to me

[twoqu]

Looking at the diagram it looks like Fuse S12 feeds the voltage stabilizer J6 from C15a. It then runs along track f1 to the tacho. Not sure where C15a is but if its at the fuse box perhaps its been dislodged when adding the other feed.
Start at page 15/6 and follow the trace to the tacho. It's spread over a few pages.
Having said that I would have thought it would have meant a dead instrument cluster in effect.

[Error404]

Thanks dude, I'll check that out

So is C15a a connector on the bottom of the fuse board? Never quite understood what those tracks at the top meant!

[twoqu]

Bad eyesight! Looks like track e1 not f1. Both are fed from the voltage stabilizer to the various instruments.
I think if it appears in the top of the schmatic its usually in the fuse box.
Do the reversing lights work?

[Error404]

Cool, thanks!
Yeah reversing lights are fine

[Error404]

Right i think I've made some progress with this finally. It appears the rev counter and oil pressure warning are separate issues.
Unplugged everything from the aux relay panel, all the earths and the aux relay connectors and liberally sprayed with contact cleaner.
I also undid all the earth posts and cleaned those up too, put it all back together and I now have a working rev counter.
Not sure what caused that but obviously a poor connection somewhere.

Still getting the oil pressure warning, but I grounded both the connections to the oil pressure sender / low pressure switches and my gauge zero'd.
So now i think the pressure sender is dead. Will try a new sender unit. **** knows how to get it off with the engine mount in the way and head still on the block...

[johne]

I got in from the front to replace my sender by removing the pump for the brakes and power steering.

Sorry if you already know, but it's not the oil pressure switch combined with the sender but the oil pressure switch that's on it's own that's monitored by Autocheck for oil pressure only above 2000 RPM.

John

[Error404]

Cheers mate. Yeah i figured if the gauge sender part of the unit is faulty chances are the 0.3bar low pressure warning is too, so I'll get that changed, may as well do the 1.8bar sender at the same time, hopefully that'll sort it

Cheers for your help guys