JohnJo

Hi Andrew, you came to my rescue by fitting a new alternator for me when mine failed. You are welcome to check out my mapping if my Caterham is of interest. Unmodified 1.8K X Power. No idea if it's Roadsport or Supersport but was advertised as Roadsport when I bought it. No idea if X Power makes difference to standard mapping. I'm in Markyate, Herts, near Harpenden.

John at purethought dot co dot uk

That's what I do Paul. I'm now into my second year of ownership and really had no idea what to do over my first winter. That first year was a bit of a trial as I have an unpowered garage so after a few close calls of almost not starting on a fine winters day with a drive planned I eventually gave in and took the battery out.

That was a pain too as whenever it was a fine (but usually cold) day I would think about taking the seven out but that whole battery re-fitting & removing thing often put me off. The arrival of spring had me at a local sports car garage having a battery isolator switch fitted. Best money I've spent on the car.

This winter I plan on using her whenever the weather suits, usually on a fine day after rain has washed salt away. I'll commute to work in her when I can and take her out on weekends. I don't like leaving her idling early morning when neighbours are still sleeping although she'll get a few mins while I close up garage and strap in. I keep her below 3000 revs until water is up to temperature and oil pressure settles. 1.8 K series.

This problem has now been solved with the kind help of Andrew (revilla) & Jonathan Kay. Andrew suspected a:

"faulty diode in the rectifier section of the alternator" which  "can leave some phases of the winding coming into play and some not; the result being pulsating voltage at the regulator with regular dropouts. So the battery will still charge (over most of the cycle, so not full strength) but the warning light may still be on (over the rest of the cycle, so maybe not full brightness but sometimes hard to tell). A multimeter wouldn't show that fault very clearly, the waveform is too fast. A scope probably would".

Amazingly Andrew offered to stop of at my place on the way elsewhere and replace the alternator with a unit he already had (we did keep our distance, which was relatively easy). I fired the Seven up and no warning light :)

Thanks again to them both and to everyone else for their comments and suggestions.

Update FWIW: Handbook shows the 7 went back to Caterham to have a starter button fitted very soon after original purchase. Not sure if relevant.

So this is what has been discovered using a multimeter with guidance from JK:

Reading at battery with engine off: 12.47
Reading at battery with engine running: 14.16 dropping to 13.9
Reading at battery with engine running at 3000 revs: 14.24 dropping to 14.17

Ignition Warning light remains on after ignition/engine running, which wasn't the case until a few days ago.

It's been suggested to me that the problem could be the connector behind the tacho. I've had a feel around and found nothing loose.

I may have to just live with this until I manage to get her to mechanic at end of June.

Hi John,

Thanks for the reply. Will see what the multimeter says later on today.

Thanks for the reply. Jonathan has been kindly walking me through some stuff. So far all the wiring from the alternator to the battery seems solid. Belt good. Have ordered a multimeter and will take it from there.

Hi all,

About 20 mins ago Spanky's red engine warning light came on. (Ignition Warning Light)

2002 140 SV 1.8 K Series X Power, unmodified. About 22,500 miles. Overdue a service by about 5 days.

I was pootling about for about 35 mins, grinning mostly, then accelerated hard for a couple of overtakes just before home. The light came on just after second acceleration.

Oil pressure as normal (mechanical stack), engine temperature as normal. Engine still responsive and sounding good.

Garaged it. Turned off and set imobiliser, then disabled imobiliser and restarted. Light still on. 

Any ideas appreciated. Last engine I took care of myself was a Spitfire 1500 so not up to speed...

Cheers

UPDATE: Handbook says "Ignition Warning Light" (not, as I put, "Engine Warning Light")

I use ultra tape extra strong foam mounting tape product code 45669 from tool station which comes in a 25mm x 10m roll just trace round the mirror base cut out with scissors for a perfect shape the clean your screen with isapropyl  alcohol to degrease it and then place where you want it...you only get one go because I misplaced mine and it's properly stuck on !

you can also use the tape for lots of other uses on the car such as number plate mounting etc.

And it also only costs £2.99 per roll  

Just a quick update on Ralph's suggestion. I bought a roll of the recommended tape, cleaned the screen area as suggested and it seems to have worked a treat so far (though, obs, not driven a massive amount). The tape is easy to work with and super sticky.

Hi Mark,

I was in exactly the same situation as you. Garage in a block with no power & a K series 7. For the first winter I ended up having to remove the battery after a drive and bring it into the house for charging on a ctek charger as a couple of weeks or less would see the immobiliser drain the battery. I had an isolator fitted with the switch located on the bulkhead near the fuse box on the passenger side but easily operated from the drivers side (harness off).

It really changed the way I used the car over winter. Previously, moments of opportunity to drive the Seven were tempered with the fact that I had to re-fit the battery first which had lazy old me sometimes not bothering. The isolator changed all that.

It's well worth doing.

Hi Ralph, will give it a go. Cheers!

I've never managed to get my mirror back up again since it fell off. Alcohol wipes, gentle screen heating, just won't stay on. I had a good look around for alternatives, eg something that could clamp over the top of the screen but still allow half roof on but to no avail. I know, it's a big ask for something like that I guess. Closest I found was this:

https://www.vintagecarparts.co.uk/products/a-17681-interior-rear-view-mirror-6

But would need removing if half roof needed to go on and profile probably wouldn't look good.

I currently use suction cup and temporary put back original mirror using stickies for MOT (with fingers crossed).

I thought I spotted a stripe but it all happened so quickly. 

You went by in a flash so only just saw you.

"Also driving on a cold dry winter day, with no HH fitted, descending into a frost hollow, the screen has misted over completely. Heated screen sorts it quickly."

This happened to me last year (my first as an owner) driving without a hood. I'd not experienced anything like it before so it took me completely by surprise. The road was entirely clear with excellent visibility but the fields either side were misty. My wing mirrors very suddenly went white, then the whole front screen in what seemed like a second. I don't know if it was a frost hollow as such (just looked it up) but it was an interesting experience.

Glad to hear you'll be back on the road.

Early this afternoon towards Welwyn Garden City (couple of miles or so from junction). Whoever you are, sorry to see you being towed by the AA.

Fantastic! Well done.

I was in the blue seven, you were sporting a white helmet as we flashed by each other waving.

Thanks guys. Good to know it can be removed.

Gulf, to answer your question, my vent hose just vents towards the floor (open ended pipe quite low down).

Paul, I have no power to the garage.

Hi all,

Just a quick one. I went to start the seven over the weekend and she really struggled to catch. Battery drain via immobilizer I'm assuming (no power to garage). I took her out for a good drive but am going to have to whip out the banner battery and trickle it elsewhere while the car is not in use (I'm eventually going to have a battery isolator fitted).

The banner battery seems to have what I'm guessing is a vent pipe coming out of it. The main length of it is quite well tied up (nice and tidy) and I don't really want to touch that if at all possible (ie remove battery with whole of pipe attached). Can I just yank it out from the top (as depicted) and then slide it back in when I refit the battery? Cheers!

We passed each other and waved this morning. I was in the blue seven.