Car wouldn't start, air-con?

[neilw]

Hello,
I've a fairly new honda crv and while stopped waiting for somebody (with engine off) I had the air-con on for about 20 minutes.

When I went to start the car there was nothing, the lights were on but the ignition wouldn't try to start.

I turned it off for 10 minutes and on retrying it worked.

any ideas? yesterday was the only time it's done it to date and it couldn't be the battery after just 20 minutes could it, as it's a huge battery and worked straight away the second time on trying.

thanks.

 

[Burnerman]

I'm a little confused by this one Neil - presumably you were stopped, but had the ignition on so the internal fan kept running? The air con wouldn't be working at this time.
Its unusual for the battery to go flat, but it depends on how much current the fan consumes. Did the ignition lights dim when you tried to restart? Did you hear a click from the engine somewhere?
If the battery was on its last legs, then a respite from the running fan may just have enough oomph to turn the engine over.
How old is the vehicle?
Bear in mind, a motor factor can easily test the battery for you, using a heavy discharge meter.
John

 

[xr4x4]

With two powerful air con fans and every other electrical item being on for 20 mins, I'm not suprised the battery lost its condition.

A good battery will recover from a short discharge over time, which it sounds like yours did.

If it where me, id get the battery and alternator checked, just in case.

 

[neilw]

Cheers. I've rang the garage and they're going to check the battery on the weekend.

But yes, it was a case of engine off but ignition on with the fans on to slightly cool the car down. So maybe it was just the battery after all. I suppose having the fan blowing would use a bit of electricity I just assumed the battery was well capable.

 

[xr4x4]

I'm pretty sure with the ignition on and the air con on, the main cooling fans under the bonnet would of been running, these pull quite a few amps... Each..

Plus the fan inside the cabin, plus possibly the radio. Also with the ignition on, a whole host of electrical accesorys would have been on.

Don't sit with your ignition on for long periods of time, that's why the radio works on one click of the key, also sometimes they will work without the key at all.

 

[Stivino]

You can't have the A/C on with just the ignition on, it needs the engine running to turn the compressor.
So, at the very most all that could've been on was the heater fan, the radio and, maybe some lights.
But it does sound like your battery wasn't able to cope with it which is surprising as these things don't draw an awful lot of current.

 

[xr4x4]

You can't have the A/C on with just the ignition on, it needs the engine running to turn the compressor.
So, at the very most all that could've been on was the heater fan, the radio and, maybe some lights.
But it does sound like your battery wasn't able to cope with it which is surprising as these things don't draw an awful lot of current.

Why don't you try it on your car?

I think you will find that the fans on the radiator will still run, even if the engine is off.

 

[Stivino]

I know very well that the fans might run. However, it would all depend on what you were doing with the car in the run up to leaving it with the ignition on.

 

[Nige F]

In our peugeot 207 the system shuts down accesories and goes into economy mode - radio goes off and info appears on computer screen - kinda surprised a Honda doesn`t have that feature. Saved me from the same scenario as the OP , once