Hello,
2003 Highlander 4 cyl. with 240,000 miles.
Battery light has flickered intermittently for the better part of a year. Will even go days or weeks without coming on.
As of the last couple days the light has been on solid.
As Scotty suggested I took it to a mechanic who specializes in electronics. I was told everything is charging properly however, it was discovered there is an issue in the alternator that causes it to not relay the signal to the dash to turn off the battery light. In other words it is a false positive. The main issue here is that there's a chance if the alternator does go and is not charging the battery, I won't necessarily know because I have that false positive coming on all the time.
Was quoted $450 if I wanted to replace the alternator.
Is it safe to drive around if everything is charging properly? If worst case the battery did die, should I be able to just jump start it and drive on my way?
Do you have volt gauge in your instrument cluster? Unfortunately on some new cars they've started leaving out vital instruments.
If not, then you can buy one that you stick in the cigar lighter socket. Very inexpensive. It will allow you to monitor your alternator output. If you see that voltage drop below 13.0V, then you know the alternator is giving out.
You can use booster cables to start with a dead battery. But you won't get very far with a dead alternator, because they power everything in your car.
@mountainmanjoe
Thanks for your reply. I’ve ordered a cigarette socket voltmeter as I do not have a voltage reading on the dash. Is this issue of the alternator not giving the signal to turn off the light an indication it is on its way out or not necessarily? What would warrant me replacing the alternator if it’s been doing this for a year or so without any issues besides the light itself? If my voltmeter ever does indicate it is undercharging how long do I have to replace the alternator or is it too late at that point?
I'm not sure about the warning light in your cluster. I would have to find schematics for your vehicle and figure out how it works.
Your alternator could be perfectly fine. The voltmeter will show you. If voltage is good, and the pulley isn't noisy, then there's no reason to replace the alternator. If the light bothers you, then put a piece of black electrical tape over the light haha.
If you notice that it is undercharging then turn around and go straight home. You can still drive for some time so you should make it. Put a charger on the battery. Then replace alternator immediately.
It should only take an hour or so of labour to replace it (~ $100/hr). You can buy decent alternators for around $150. He's probably quoting you for an original Toyota alternator which is more expensive.