Battery problem with roof down?

[RHT45]

Well the roof came down last Saturday and I'm really enjoying having an open car after a very long time. It helps that the weather in Scotland has been great for the last few days and we have a lovely sunny day again today. The hood has stayed down and I'm hoping not to put it up again soon. However.......

When I wanted to start the car a couple of days ago the battery was way down and I had to jump start it. No problems with that and a half hour run left the battery showing 12.4 V on the multimeter so I thought I'd leave it a couple of days and see what it read.

Today it was showing 7 V so it's on the conditioner and very quickly back up to over 12 V, but I suspect the battery is goosed. It's a Bosch S4 008 74 Ah and I've no idea how old as I bought the car last December. I've used the car intermittently over the winter with no starting problems. I'm about to get it checked but two questions:
1. Is there any chance that there's a switch somewhere which is draining the battery when the hood is down? I can't believe so, as they'd never have sold any cars in California! The car has the original separate immobiliser set-up.
2. Am I going to have any problems when I reconnect the old/new battery e.g. with the ECU or the radio/CD (which is a very garish Pioneer thing)? I didn't get any codes with the car.

All contributions gratefully received. []

 

[clyde]

The fan at the rear of the ccu can sometimes run continuously, running the battery down over quite a short period of time Richard. You can check the draw on the system with everything off by running a multimeter between a lead and the battery. It is frequently intermittent though.

Disconnecting the battery will reset the ecu but this just re-learns over the next 15 minutes of driving. Don't know about the radio.

 

[A Ward]

If you connect the multimeter between the lead and battery (with everything off) - then theoretically if you do have anything drawing current still it would be possible to narrow it down by removing/refitting fuses one at a time until you identify which system is causing the drain. Once you have identified that then you at least know where to look/investigate further.

 

[nfearn]

It would probably be a worthwhile investment for you to buy one of the books that cover DIY car electrical systems and a reasonable multimeter if you don't already have these. I have a Haynes manual but there must be others.

These will enable you to do guided fault-finding and make diagnosing this type of problem so much easier and more cost-effective.

 

[RHT45]

Thanks, everyone, for the handy hints. In fact I do have the Haynes book on vehicle electrics and, though I struggle with some of the theoretical stuff, having been a classicist not a science student, I eventually got my head round the workings of the alternator and the regulator/rectifier, so was able to sort out the much-loved (and now much-missed) VFR. I also acquired at that point a proper Draper multimeter which does dwell angles and everything, in fact loads of stuff I shall never understand or use, but I reckoned if I bought one called the Expert, it would make up for my ignorance! [8|]

I tried checking for current drainage but realised that the alarm/immobiliser was on, and couldn't think immediately how to switch it off, so just took the battery to the local garage who tested it and confirmed it was beyond help. A quick visit to the motor factors and I was up and running with a replacement, which holds a charge, so problem solved. [][][] I presume that you can just remove the appropriate fuse to disconnect the alarm, but that can wait for a rainy day when there's nothing on telly.

BTW you were right, clyde, about the ecu. The car started instantly on the new battery and the radio worked, so happy days! Now enjoying the better weather and the chance to stretch the car's legs a bit - they seem to have grown since I had the Terraclean treatment done yesterday, but that's another story......

 

[clyde]

Hopefully that's all it was but don't be surprised if the symptoms re-emerge once the battery starts to get a bit tired.

Who did you get to do the Terraclean Richard? I tried to get mine done a year or so back but the garage didn't have the right adaptors to connect to the car and apparently Terraclean couldn't supply them. or at least couldn't advise which ones they needed.

And the obvious question, how much did they take?

 

[RHT45]

I've 4 years warranty on the battery so not too worried. Who knows if I'll still have the car by then? Loving it so far but aircon would have been a bonus; it takes forever to demist on start-up if it's been parked outside on a wet,cold day, presumably the combination of a soft roof and the less than brilliant heating system. Maybe I shouldn't use it in the winter............. [&o]

I went to Haynes Vehicle Services in Thankerton (about 5 miles west of Biggar) for the Terraclean treatment. Kevin Haynes was the first franchisee in Scotland and he knows his stuff. It's all a very snug fit around the engine but he made up a connector in a few minutes and the job was done in about an hour. He charges £90 plus VAT up to 2 litres engine capacity and £105 plus VAT for anything bigger. It's made such a difference to the 911 I'm seriously considering having it done to the diesel Civic. If you're interested I might start a thread with a couple of pics, as it might be of interest to others too.

 

[clyde]

Thanks Richard, I'll give him a call when I get back from holiday. I've had a slight missfire at low revs for a wee while and would like to give Terraclean a go before going to the hassle and expense of replacing the injectors. I've replaced leads, dizzy caps, etc and while this all improved the overall power delivery it didn't sort the missfire.

A new post and pics would be good.

 

[RHT45]

I'll do a piece on Terraclean tomorrow, but in the meantime and back on the subject of batteries, I finally started to pull the VFR apart to see how bad the damage is, and the battery was very down, to the extent that the starter/solenoid just ticked without turning the engine over. Fair enough, as it went down the road last July and hasn't moved since or been on charge, as there's no power in the shed. Removed the battery and hooked it up to the Optimate conditioner - 10.4V! Not bad after 10 months for a little 12V Yuasa bike battery, even if it was fairly new a year ago. Now back up to nearly 13V though whether it'll hold a charge is another matter. Not that it matters to me as it's most unlikely to be ridden again.[]