More electrical problems - help before I burn it

[Lee H]

Right, finished building the Nova turbo back up and it was cranking over fine to build up oil pressure so I plugged the ECU in and tried to start it up.

When I turn the ignition to try and start it the indicators and headlights come on really dim, ECU light goes off and the oil pressure guage goes up to full. Unplug the ECU and its still the same so its nothing to do with that. Also when I plug the ECU in the oil pressure gauge goes up 2 blocks on the dash and back down to nothing when I unplug it. The fuel tank vent valve clicks in the engine bay too as I plug/unplug the ECU.

Does this sound like an earthing problem or can anyone think of anything else?

Lee

[Rick Draper]

Burn it! I want the cage though.

[Paul]

I always unplug the tank vent valve, theyre poor design, always break causing problems etc.

Make sure remove the pipe going to it though.

As for your main problem, it does sound like a weak earth somewhere, not taking the piss here, but you sure you got the dash signals wired in properly?

[Lee H]

I always unplug the tank vent valve, theyre poor design, always break causing problems etc.

Make sure remove the pipe going to it though.

As for your main problem, it does sound like a weak earth somewhere, not taking the piss here, but you sure you got the dash signals wired in properly?

Tried unplugging it but no difference.

It was all working earlier in the day which is what I don't understand. The dash is definitely wired in right as its been in years.

[Lee H]

Burn it! I want the cage though.

If its being set on fire its all going up unfortunately. Should have thrown a match under it when the fuel line split the other day.

[Adam]

Does sound like an earth problem
Check the engine earths(earth strap/fuel rail connections), and the inner wing headlamp/indicator earth.

[Lee H]

Is the brown earth that connects to the chassis leg the earth for the whole car loom or just the headlight/indicator part?

I've fitted a new engine earth strap as the old one was in a bad way.

[Adam]

The thinnish brown earth that goes to the inner wing/chassis leg from the headlamp area is the earth for the headlamps/indicators etc.
I forgot connect that on mine and had a load of weird problems, headlamps flashing with indicators etc lol

So id look at that first.

[Lee H]

I know its connected but maybe there is paint in the bolt hole stopping it earthing properly as most of the problems seem to be lights related.

Most puzzled as to why it was working in the morning and not in the afternoon even though I didn't touch anything!!

[Adam]

Maybe yeah, run a tap through it to clear the thread of paint.

Altho, if it randomly started acting strangely without you touching anything, it probably isn't that.

[Lee H]

Might try a different battery too before I start pulling it all apart again although the one I have is brand new.

Only thing I can think is I was rocking the engine about removing the driveshafts but can't see how that could have disturbed anything.

[Rick Draper]

Try ****ting the starter motor lee.

[adzgsi]

carry out an earth volt drop (use a multimeter) set meter to volts dc place your black lead onto the battery negative and the red multimeter lead onto a metalic engine component ie headbolt or alternator casing you should see 0v also place red lead on your main earth points ie gearbox earth strap bolt.if you see a volt reading connect your jump lead to negative terminal on battery and the other end to engine casing and retry.hope this helps.adam