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Immaculate condition, 1.6 Ford Sigma 125 bhp, 6 speed, lowered floors. Full details here: https://www.pistonheads.com/classifieds/used-cars/caterham/all-models/caterham-super-seven-2015/7172588

I don't know why my 7 is so unique regards this problem, probably never will. But I do have one final question, could this fix be responsible for an improvement in performance? I'm convinced my car is quite a lot "friskier " than before. At first I put this down to having not driven the car for a while. The next time I drove the car it still felt very frisky, which may have been due to the the frosty weather. But I've driven it again recently and I'm sure it's quicker. Could it be the fix had resulted in a better spark at the plugs? That's the only thing I could think of.

this is the "repaired" item..

They split around the front edge, so just behind the black plastic bead/rim. It's actually the white plastic body that splits away. Oh and the posts have broken off too. I'll try to post a picture of it. regards, Will

On a related topic, my sigma gauges keep splitting! oil pressure first and now temp. The car is only 18 months old, anyone else had this problem I wonder?

So, just to close this one off. Having confirmed the battery & alternator were both good, I took the car back to Bristol Auto Electrical for them to diagnose the fault. Thankfully they did find and fix the issue. The problem was a faulty earth connection, possibly the one that goes to the chassis near the alternator. BAE said that they had carried out lots of voltage drop tests and resistance checks and noticed that when they simply put the car into gear, the charge level began to drop a little. So just that small engine movement was enough to trigger the poor earth connection. BAE's preferred fix was to introduce a new earth strap going from the battery earth to the starter motor. Job done, my temporary volt meter is now showing charging levels of around 14 volts, higher than I've ever seen! Whilst reading some of the content on here recently I noticed a post by somebody that said "90% of electrical issues on 7s were caused by poor earth connections". I'll bear that in mind for the future and try to improve my own diagnostic & multi-meter skills. Thanks again to all who've helped me with this :-)

Sorry - without*

Thanks Tom, no it goes flat on a long run within lights on. I'm taking it to an auto electric place tomorrow as I'd really like to have it resolved for any Christmas blast. TTFN

Just an update - I've had the alternator off and tested, it's 100% fine. So I think it's a wiring fault....

Thanks Chris, I think I can see which one is the tensioner now. just gonna have a crack at it now... regards, Will

Hi all, is it the same or similar process for the 1.6 sigma please?

Many thanks for the info guys, working away ATM but will progress when I get home. regards, Will

Hi chaps, I've ordered a replacement cable from CC. any tips on how to do this "It would be interesting to measure the voltage at the live terminal of the alternator at the same time that it's low at the battery." Whilst I have a multi-meter I am a novice with it. thanks, Will

Thanks Jonathan, I'll do that. Not sure how this issue fits with the intermittent nature of the fault but I'll do as you suggest and see how it goes. I'll keep you posted. Thanks again, Regards, WILL

thanks for the super prompt response :-) here is the suspect wire:

Hi, I have some readings and additional info: Engine off (with no chargeconditioner for just over 1 week) = 12.4v Minimum seen during cranking = 11.4v 3,000 rpm = 13.75The issue only seems to occur with extended use, so drive the car for an hour and during that time the battery, instead of charging, discharges (down to 11.4v last time around). I bought a new battery some 5 months ago believing that to be the problem. At that time, the supplier put their diagnostic equipment onto the car, found no issues and so assumed it must be a 'sulfated' battery that would not hold charge properly. Also, its worth re-highlighting that when the car is in the 'fault state', and revving at 3,000 Rpm the mult-meter shows the volts across the battery actually decreasing. I have carried out some of the other checks too: The alternator is fixed firmly and the alternator belt is in new condition and very tight. All connections look good, tight and clean. The car is a 2015 sigma with only 3k miles so I don't think wear is too much of a concern in this case. However, there is a cable that goes from the alternator to the starter motor and there appears to be a kinkcrack just below where it attaches to the alternator, I'll post a picture shortly. I was trying to disconnect it from the alternator to check further but there is a silicon 'blob' on top of the nut and I'm struggling to undo the nut without ripping the silicon 'blob' from the nut. What do you guys think? Thanks, Will

Thanks Jonathan, I'll make those checks and re-post.. Regards, Will

Hi, things have developed... I've been on a couple of club blats and experienced the flat battery problem again. I always set off with a fully charged battery as I keep it on chargeconditioner, also its a new sealed battery. It appears as though when cold the battery receives charge from the engine and all is fine, when I go on an extended run the battery discharges to the point where it won't turn the engine over (11.4 volts). At the last runbreakdown the AA guy put his meter on the battery and when revving the engine we saw the battery charge level dropping! he diagnosed a wiring fault between the starter motoralternatorbattery. Any suggestions on how I could further diagnose this please? I do have a multi-meter (see earlier posts) but could do with some tips on how where to apply it to gain further info on my problem. Thanks in advnace ... Will

good to know, thanks Ian.

:-) thanks Ian

he told me that he'd looked through the owners manual but there was no description in there either?

A 'friend' of mine was wondering what that black rubber covered button just behind the battery was for?

:-) very good

by the way Jonathan, if that muli meter is 2nd most useful item, what's the first?