Jonathan Kay

How about finding an HT tester and seeing what's happening in the plug leads as it gets hot? Or trying different plug leads if that isn't possible? Jonathan

Well done. But I'd still want to know that it isn't on its way to meet its maker. The PC680 is pretty small, sealed, gel type battery in a dedicated aluminium tray, mounted on its side, so when one breaks, there seem to be few options for replacement. Have a look at the Powervamp Clubsport EP. And then there's the Great Lithium Question. Jonathan PS: The PC680 isn't a gel type... the G in AGM stands for "glass" or "glass fibre".

Are the minilites exposing more thread on the studs? Have the studs bottomed inside the closed nut which has then spun and stripped the threads. That was what I suspected. Jonathan

How does the HT side work on your engine... one coil and traditional HT leads to each plug? What plugs did you fit? Jonathan

What was the sequence of events that led up to the stripping? First time those nuts had been used with those wheels? Open or closed nuts? Tool used? Torque applied? Jonathan

I don't know a better approach than that, and it's what I do. But NB post#2. i would connect it to a vehicle battery via jump leads, then start the engine and charge it from the alternator. Any reason for preferring that way to using a trickle charger? Jonathan

That's sealed rather than topuppable? This isn't unusual. And I'd do exactly what you're doing, but get it back on the Optimate as soon as possible to avoid overcharging. Then you have to work out after that whether it's shot while it's somewhere convenient rather than... The Clubsport that Powervamp recommend costs a lot less than £90... I've just fitted one. Jonathan PS: If it isn't sealed Roger and others might suggest a rejuvenating pill. I'm not convinced, but if you're about to throw it away there's not much to lose.

I'd vote for one of those. Especially as otherwise my vote will be wasted AGAIN. Jonathan

I'd exclude a couple of simple things first. What's the battery voltage at rest, minimum during cranking and at 3,000 rpm? It's fading before stopping. If you remove the filler cap while it's running can you hear air rushing in? Does removing the filler cap prevent the stopping?Jonathan

I've had one search which had about 3,000 hits (!) but didn't seem to give the answers I was looking for. But I'll have another go. Just try a different search query......... How about these as a starting point? https://www.google.co.uk/search?q=site:lotus7.club+wheel+clearance https://www.google.co.uk/search?q=site:lotus7.club+wheel+offset Good luck Jonathan

What do I need to know to find out if a particular style of wheel from a non-Caterham supplier will fit my car? IIRC there have been problems with insufficient spacing on the inside surface... but I can't remember what made contact. Searching for that in the archives might reveal the required clearance and specs. Jonathan

... its finding the right wire with a meter i guess Have you got the wiring diagram for your car and the table of standard wiring colours? Jonathan

George Polley Motorsport... but the site seems to be down. (Edited: Now back online.) Jonathan PS: There's a Club discount at E Tyres.

Nice work. Have you got the whole layout sorted and documented now? Jonathan

You've posted that three times... can I help? Jonathan

Someone must want to know how fast their engine is turning... :-) Jonathan

Sorry, I don't have a good explanation. A few thoughts... 7.8 V while cranking is far too low. As well as the starter not spinning fast enough electronic stuff might drop out. You've got sparks and fuel... but has it ever fired? The battery is probably duff, but we still need to see it starting reliably off another electrical source. That JumpStart device has a lot of nominal oomph, but is it fully charged and working properly? I'd try starting by jumping it with fat cables off another car with the engine at 3,000 rpm and again measuring the lowest voltage seen while cranking. Fuel is at least 6 months old... I'm not convinced that it gets tired but others are. Try a puff of ether in the air intake? Jonathan

Shows 12.7V on starting, but only has energy for 2 starting attempts at normal turnover speed, then rapidly slows to stop after a further 5 goes. Voltage at end 12.4v. I'm not sure what you mean by "on starting". What's the voltage at rest, and minimum seen during cranking? Has it fired at all? I'd check all the relevant wiring and connections, including the battery terminals and engine earths: inspect, wiggle, disconnect, clean and reconnect. I'm not familiar with a Clarks Quick Starter: what is it? Do you have another battery or vehicle you can use to jump the 7? Jonathan

Probably on the bulkhead above and behind the ECU. Jonathan

Its in the "Fuel pump relay" cluster of fuses, but the diagram to the left calls out F as "Instrument lights". It may well have a dual purpose. That sounds unlikely... we probably still don't have the right layout yet. Please could you check your Assembly Guide and Handbook when convenient. One of my mates yesterday questioned why I didn't have a fuse "grabber" or whatever they are called. The little plastic tongs that make life really easy to extract the fuses. Its a really good point. Caterham should supply one clipped into the fuse area. Maybe its a weight reduction thing?! Anyone thinking about fuses might also want to consider: Fuses that show a little light when they've failed. Resettable circuit breakers rather than fuses.Those are both available for blade fuses and probably other formats. Jonathan

Thanks, all. I'm happy to get another batch, but they come from the factory in China and we're still way below the previous size of order. Jonathan

I'd check, in order: That the inertia switch is reset. The electrical feed and earth at the pump terminals.Do you have a multimeter? Jonathan

Yes. The switch is going to be a neater version of you connecting that wire to earth by hand. Jonathan PS: You can probably ignore the next bit. I know that you've measured 12 V on that wire, but I don't think of it that way and wouldn't call it that. It's a switched earth. It's only showing 12 V because it's connected to the 12 V feed through the filament of the lamp and there's no current flowing at the moment.

I assumed the only difference was the connector so swapped the the press stud for a bullet, connected it up, but it doesn't work. Was that only that the light didn't come on when you expected it to or have you checked the switch and circuit in some other way? Have you shorted the wire to the switch directly to earth, and if so did the light come on then? Do you have a multimeter? Jonathan

The foam issue seems to be full of varying advice... Yes. What I'd like to see is all the evidence and opinion in one place, with who is saying what and why. That document doesn't need to be agreed between those with different views; it would just make it easier for us to make up our own minds. Jonathan PS: As I've advocated previously a facility for multiauthor wikis would be very helpful, but this issue is so important and so recurrent that we should do it as a one-off. Do we have a volunteer coordinator... or should we try a Google document?