Got some question that need expert advise or anybody that already experience this type of scenarios:

1. How whould you know if your alternator is about to give up?

2. medyo humuhina yung ilaw sa gauge pag tinapakan yung brake

3. pag on ko ng aircon ko, RPM goes up to 1200 RPM (Normal) then go down to 900 (Normal padin) but nanginginig yung dashboard

4. pag dumadaan ako sa mga lubak, napapansin ko RPM ko bumababa to 600 RPM, pero pag rev ko siya bumabalik sa 900 ulit..nangyayari lang to pag dumaan ako sa lumak..

Oto ko pala ay Corolla 4AGE Silvertop

Any inputs would be greatly appreciated...thanks