Help - no electrics, just loud click

[IanT]

Just tried starting up for a final Bank Holiday blat ...

 

Here's exactly what happened:

 

- Stack dash came on OK, fuel pump started whirring

- Pressed the Start button and everything shut down ... a few rapid clicks came from the left hand side under the dash (i.e. near the fusebox) and then nothing

- After a few seconds, the Stack dash came back on but then another attempt to start resulted in the same symptom (complete shutdown, a few clicks and then nothing).

 

After a couple of experiments, I think it's a fusebox problem possibly relating to some type of tripper switch (here's where you'll gather that electrics are not my strong point). Pressing the horn button results in a single click from (near the?) fusebox so the problem is independent of the ignition key.

 

The Stack will come back on occasionally (along with the fuel pump) but any further attempt to use any more power results in a complete shutdown again.

 

Any thoughts? The car is a Blackbird.

 

Thanks in advance,

 

Ian.

[IanT]

Hmmm .. one very loose relay, refitted it but no joy.

 

I guess it might be a completely flat battery (?) I've put the trickle-charger on and the horn now works (but faintly).

 

So if it is the battery, what's the click? Relay going on & off as I try to use power for something else?

 

Ian.

[Chris W]

Ian

 

It does sound like the battery charge. Clue was the horn in your first post which clicked but didn't blast. ie: there's enough power in the battery to operate something miniscule like the 100mA needed to trigger the relays (hence the click), but not enough to operate the device to which the relay is connnected eg: the horn, lights etc at several amps. You don't mention the lights but this is always a good indication of charge.... flat battery.... headlights come on only dimly.

 

There is no "tripper" switch involved in starting. The rapid clicks were probably one of the relays cycling on and off. For example, the fuel pump relay could close OK but when you try to start the car the battery cannot supply the power and the voltage drops to less than that needed to trigger the relays. Therefore all the relays release, disconnecting power to the solenoid, so the battery voltage rises again - enough to trigger the relays so the solenoid closes again - but the solenoid drags the voltage down again and all the relays release... ad infinitum. You get an oscillation effect as the battery voltage rises and falls. All classic symptoms of a dying battery.

 

I wouldn't put it on trickle charge if it is flat - it will take forever to charge. Put it overnight on a proper car battery charger which can deliver 3 or 4 amps. The trickle charger will be only charge at around 150 - 200mA so will take maybe 20 times as long to charge the battery.

 

Why would the battery be down? Had you left the lights on or not charged it for a month?Important to know why.

 

Chris

 

1.8K SV 140hp see it here

[IanT]

Thanks Chris ... yep, that looks like the problem.

 

It's a charger that someone lent me and it's the first time I've used it (it's a proper car charger with a switch for "motorbike", which is handy). I left the charger on the battery for about 20 mins then tried again. All electrics OK and engine started first time. Quick blat (well, umm, 1 hour) and only an occasional warning from the Stack of a low battery voltage (11.8V - 12.5V) which is normal.

 

Over the past couple of weeks it's failed to start once before ... connecting it to the wife's 525's battery shocked into action easily enough. After that it stood for 1 week and fired up perfectly first time.

 

This is the first time it's been completely flat and I will put that down to my 2.5 year old daughter playing with the lights, main beam flicker and horn when I'm not looking. I assume that, as it's a tiny motorcycle battery, it holds "just enough" and too much playing with the gizmos when it's not running is enough to finish it off.

 

It's due at Caterham soon so I'll get them to check the alternator. They'll be fitting a battery master switch for me so that will come in handy.

 

Ian.

[ChrisC]

Hi Ian

 

Have you got power where the car is stored? If you have the solution to this problem will cost you about £25. It's an AirFlow Battery conditioner. This conditioner is connected to your battery all the time it is stored, and will keep your battery ready to run all the time. It will save you money in the long run, because the Banner Battery does not take to kindly to being flattened, an will normally needs replacement at a cost of £50.

 

Hope this helps

 

PS I have no connection with Banner or AirFlow, just trying to lower the cost of ownership to fellow enthusiasts.

 

 

 

Chris....

H15 SVN Get it !

[danwhiley]

Ian - might be a silly thing to check, but see if there is a good connection at the positive terminal of the battery. I had this problem a while ago and it transpired that blatting around corners causes the battery acid to slosh around and causes a degree of corrosion of the positive battery terminal. Eventually this got so much that there was no decent electrical connection there, hence it wouldn't charge properly.

 

Pooring boiling water on the terminal cleaned it up a treat, followed by a but of wire wool and topped off with some vaseline on the re-assembled bits to stop them getting soggy again.

 

Dan.

[Ralph Morgan]

Had exactly the same problem last Friday. I knew the battery was OK as I'd been to the local meet the evening before and all was well then. Eventually traced the problem to a failed cut-out switch (an in-line, rotary knob type fitted to the positive terminal, not the key operated external type). Took this out of circuit, remade the battery connection with a plain terminal, problem solved