Yet another stupid problem on the Caterham SV. Earlier this year, while fiddling with the problems connected with getting the thing running, which were many, I somehow fritzed out the original electric oil pressure gauge and or sender. I replaced it with a brand new VDO unit and sender, it worked ok, but then somehow, I suppose it's possible wires were connected inversely for a second, the second gauge died too.

Sick of the apparently fragile electric units, I ordered a Smiths Telemetrix mechanical replacement, and a mechanical oil temp gauge to go with it.

I fitted them yesterday and was just finishing plumbing them in this evening, drilling holes in the bulkhead and while feeding the braided tube for the oil pressure through, I saw a tiny puff of smoke.

I realised the bloody braided tube had touched the battery live terminal and was making a dead earth to the dash (via the instrument)....thank goodness it wasn't an electronic one or that'd be another dead gauge.

It was only in contact for a few seconds ...I hadn't expected any such problems as the battery was isolated with a cutoff handle just in front of it, but there wasn't a proper rubber protection on the + terminal.

Now, when I try to start the car, I'm getting a click from the MFRU and no fuel pump noise, and it doesn't even turn the engine over.

What have I managed to trash this time?

The ECU (Emerald) still shows a red light at ignition on.

Is the MFRU the same as on a S1 Elise? If so, I could pinch one off the Elise to check...

I would check fuses...
Sounds to me like the fuse for the starter relay has gone for one.

Worth a look!

I'm no expert, but as there is no fuel pump noise, could it be an immobilser issue?
I hope Eugene is right and it's just a fuse though, good luck

I thought immobiliser, but in fact I'd immobilised the immobiliser and alarm some time ago by unplugging the unit..

I have actually discovered the source of the problem, the ecu fuse was lying on the floor....so HOW was the ecu red light managing to come on at key turn? I didn't suspect to find its fuse absent....

Anyway with the fuse back in its accustomed hole, the car starts normally.

I'm assuming it fell out while I was using a very vibratory hole enlarger near the fusebox just a shrt while before the err...incident.

Weird.

Check the new MECHANICAL instruments...the silver knob is the Emerald 3 way mapping switch.

Good to hear it's working again

One thing is very interesting about this, the Caterham ecu fuse does not, in fact, seem to be protecting the ecu. I wonder if this is always the case when an Emerald is fitted? If so, does the Emerald have an internal fuse?

I think with the OE MEMS ecu, the fuse if removed would have taken the ecu out of the circuit, but I have a hybrid system with a car which started life as EU3, has most of an EU2 engine wiring loom but running wasted-spark and coils in head...

Hal, what alternator do you have? Some, like the Raceline supplied one need a battery +ve feed to a small terminal near the main connector.
when I installed the Emerald K3 ecu, I found I couldn't, switch it off, as there was a feed back to the ignition switch through the alternator, I isolated this by installing another relay, energised by the ign switch, perhaps your switch is wired similarly, As for fuses, well mine has re-settable circuit breakers.
Regards Nigel.

Nigel,

It's the stock 2002 SV alternator. I haven't investigated this ECU fuse business any further as I've been working on other cars. It's not a major problem anyway, as the car seems to be running better than ever.

I will ring Carl at Emerald though, as I need to be 100% sure the thing can't revert to its "lets fire the ignition at the bottom of the compression stroke" antics again.

Once was enough....it's supposedly 'impossible' but it happened and I have witnesses!