So when im accelerating to get on the highway the battery light will come on ..... it puzzles me because the battery and alternator are new , just installed about two months ago. Any ideas on why this is happening? The light only comes on at high speeds. Also when the air conditioning is cranked and car is idling the whole car looses power..... (idle jumps up and down) upon recieving a boost from someone the car started back up..... then when taking it home the car died when stopped at a light. I recharged my battery and everything seems to be working fine, although im afraid to put the AC on. Im suspecting that the alternator could be bad....?
Did you replace the belt and check the tensioner? That would be my first place to start. If the belt is stretched or the tensioner is seized then the belt will slip at high RPM. Check the belt (cracks and rips -- in case you mis-installed it when the alternator was replaced) and make sure it's tight, and pry the tensioner (like you were installing a new belt); it shouldn't be too easy to turn it, If it's floppy it needs to be replaced.
Apart from that, it could be a bad voltage regulator, which (IIRC) is built into your alternator. The only way to know for sure is with a multimeter.
Edit: One possible reason the car died with the AC on is because when the AC compressor kicks on it puts more load on the belt making it slip more and making the alternator produce less power.
ya i have , the belt and tensioner was replaced early may. I will check over everything when i get a chance. Im thinking that the altenator may need to be switched... the one that is in right know came off of an svt.... i was thinking that it would be fine but im starting to think maybe not haha i havent actually checked into if the altenators are the same for the svt and just a regular focus. I just assumed that they would be?
(07-02-2012, 01:59 PM)2000zx3sct Wrote: [ -> ]the one that is in right know came off of an svt.... i was thinking that it would be fine but im starting to think maybe not haha i havent actually checked into if the altenators are the same for the svt and just a regular focus. I just assumed that they would be?
Your assumption is correct. Ford parts lookup shows the identical number for both regular Zetec and SVT - 98AZ10V346EARM.