Flickering battery light

[wslogue]

I''ve just bought my first TVR, a V8S. Amongst its quirks is a flickering battery warning light on the dash. It''s always lit regardless of what speed the engine is doing. A battery symbol for a warning light normally means that the alternator is not providing enough voltage but my owner''s manual tells me that this is an ''ignition warning light'' Perhaps that is just a different phrase for the same thing but the voltage seems fine on the volts meter and the battery itself is fine and is kept well charged by running the car. Is this warning light something I should ignore, or is the owner''s manual true in saying that it''s something to do with the ignition system ?

[GreenV8S]

It's a conventional 'no charge' warning light, just like you're used to on other cars. It is wired between the alternator output and the switched ignition supply, so it will comes on whenever there's a voltage difference between these two. Normally, it comes on (powered by the ignition) when the ignition is switched on and the engine isn't turning, and also (powered by the alternator) if the engine is turning and the ignition is off. If it comes on at any other time there is a problem. One scenario that can lead to big problems is where the alternator drive belt falls off or breaks. Since this also drives the water pump the engine has no water circulation and can be damaged quite quickly. You would probably have noticed this since the battery would be flat and your engine would have seized by now, but it's worth stopping and immediately checking you still have a drive belt, if this warning light comes on. A more common problem is that the alternator has failed and isn't charging the battery. You've ruled this out by checking the output voltage. The third problem, which seems to be specific to TVRs for some reason, is a faulty contact in the connector between the ignition switch and the loom. This produces a small voltage drop which can be just enough to make the bulb glow, and it will often glow brighter as you increase the electrical load. Sometimes it will blink cheerfully in time with the indicators and wipers. You can clean up the connectors as a temporary solution but for a permanent fix, do away with the connector and wire the ignition switch straight into the loom. Hope this helps, Peter Humphries (and a green V8S)

quote:I''ve just bought my first TVR, a V8S. Amongst its quirks is a flickering battery warning light on the dash. It''s always lit regardless of what speed the engine is doing. A battery symbol for a warning light normally means that the alternator is not providing enough voltage but my owner''s manual tells me that this is an ''ignition warning light'' Perhaps that is just a different phrase for the same thing but the voltage seems fine on the volts meter and the battery itself is fine and is kept well charged by running the car. Is this warning light something I should ignore, or is the owner''s manual true in saying that it''s something to do with the ignition system ?