Battery Light stays on until i REV ute

[Brett 76]

When i start the car for the first time, i wait for glow plugs to warm before I start the ute, every now and then the battery light stays on once started until i rev over 1200RPM then it goes away.

Any idea's to why this could be happening? This doesnt affect the ute at all, and she drives all sweet in between / starts first time every time.

Brett

 

[Old.Tony]

It could be several things. Worn brushes, slipping fan belt, debris in the alternator (water crossings?) ... then it could also be something in the ECU's detection, could be the voltage regulator, might be something about the battery that doesn't encourage higher voltages straight away but still allows large short-term current draw (degradation of the cell plates).

How old is the battery, does your fan belt have shiny regions on it? I'd be willing to bet on the battery. Try changing for a good one (that's capable of 600 CCA or more) and see if it continues.

 

[user 10312]

No real worry, the alternator is not getting enough excitation (field) voltage until you give it a rev. As you have had no starting issues I'd say the alternator is charging fine.

 

[Mac_factor]

+1 i have the same issue here watching this thread!!

 

[scottybobcat]

It's nothing guys, it just means that the revs aren't high enough to get the alternator to kick in. A quick rev and it kicks the alternator in to start charging, if it was staying on whilst driving you would have a problem

 

[Mac_factor]

Yeah Scotty will be honest it has never really worried me thought it would be something trivial...

 

[Brett 76]

I never thought it would be the death of the ute, like it's a simple tap of the acelerator to get it off. I wont worry any more then.

Brett

 

[qqc d22]

My old ute did the same thing for seven years so dont think your alt is on the way out. as scotty and the others said dont worry bout it