I've had my 2014 Jazz EX for just over a month now and I've slowly become aware of a slight dimming of lights and a slight lowering of engine revs with climate control (CC) or just air con on. When the engine is ticking over, this happens for around 5 seconds every 30 seconds. I can hear a fan kicking in for the 5 seconds and I've proved that it's the CC because, when the fan starts, I switch off the CC and the fan stops immediately. With CC back on, the fan starts straight away. (I thought it was the rad cooler fan at first).
When driving, I experience this as periods of slightly lower power for the 5 second period followed by an increase during the 30 seconds. It's feels like the brakes are being gently applied for 5 seconds and then released, with the car giving a slight surge.
I'm occasionally going up a gentle hill on 3rd or 4th, just enough power, then the power drops for a while, then you get the little surge. It is a tiny bit annoying.
I've looked at the battery, according to the manual and there's a little green (blue?) light glowing that's supposed to show that all is OK.
When driving with CC and Air Con off, I do not experience any of these effects.
Is this normal and just one of the downsides of Climate Control/Air Con?