I need help figuring out what is wrong with my KA Sublime 2004

[yoeydavis]

I had the bonnet up checking the oil n water. Could just b a coincidence but when that was done the car started to judder in low gear but as the speed got up it would stop. Then, as well as that, if I had to change into a low gear I noticed the petrol, mph n rev gadges would drop n the radio would cut out, then everything would return to normal when gaining speed. Then my headlights and full beam blew. I got the bulbs replaced but they went again later that day. The battery light has come on a few times but gone out a minute later; Halfords checked the battery n it's ok. I've had no problems starting it. I know everyone is thinking Alternator, but when I bought the car a few weeks ago I was told that the fan belt needed to be replaced. Everyone I've asked have been stumped and I was told that this engine doesn't have a fan belt. Please help. I'm skint n so scared to take it to a garage where I'll get ripped off as I'm female.

[TomsFocus]

Fan belt is an old term from when the engine cooling fan was actually run by the belt.  The fan is now run by an electric motor.  So the belt that drives the alternator, power steering and air con is known as an 'auxiliary belt' or an 'accessory belt'.  Is this belt making a squealing noise, particularly just after starting the engine?  Or does it look cracked and in generally poor condition?

Your problem does sound like an alternator fault to me.

[yoeydavis]

I have heard the strange noise that is assocoated with a loose fan belt, but not a lot, n I wouldn't know what it is supposed to look like tbh. I would think alternator too, but the fact that this all started as soon as I put the bonnet down is whats not making sense. It could be a massive coincidence or could I have accidentally loosened a connection somewhere?

[Tdci-Peter]

38 minutes ago, yoeydavis said:

I would think alternator too, but the fact that this all started as soon as I put the bonnet down is whats not making sense.

Sounds like its alternator related to me. Blowing bulbs means too much voltage, and lights dipping means not enough, so it seems the alternator is not regulating the voltage properly. Without proper regulation, the output voltage will rise as the rpm rises, and drop as it falls to idle.

It is just possible the vibration on closing the bonnet broke off a wire that was hanging on by a thread. On the alternator, there should be a thick cable bolted to it, and one, two or three thin wires connected. I don't know how accessible it is, but I would check for any broken wires near the alternator, and check the connector, and the tightness of the bolts on the fat wires. And the heavy earth cables to the battery. That is another possibility, a bad connection to the battery would allow the voltage to go up and down, the battery does a lot to regulate the voltage.

A slipping aux belt (still sometimes called fan belt, as Tom said), is unlikely to make the voltage rise and blow bulbs.