alternator vs. sensors?
The one thing I'm not that good at is electrics and wouldn't ya' know...
Here's the scenario:
1) Driving back from a night out, "check engine" light comes on. Only at idle RPM. Voltmeter dropping off at same time.
2) Get home, pop hood, alternator is smokin' hot. So I figure I got a bad alternator
3) Pull codes. Get 636 and 117 indicating bad readings from tranny and engine coolant temp sensors. NOT what I expected...
4) Engine is hard to start. Turn on key, voltage is low. After a few tries it starts and shows the system drawing a charge (i.e. voltage high)
5) Check engine light never came back after that first night, but I've just run the car since, not actually driven it...
In no case is the "high" or "low" voltage outside the normal range, just higher/lower than usual (i.e. dead center)
So I still think I got a bad alternator, but wanted some thoughts from y'all before I go plunk down for one:
a) is it possible/likely that the bad sensor readings are a by-product of abnormally low/high voltage in the system because the altie's going bad?
b) should I mess with changing the regulator first, or just go get a whole new alternator and not mess with it...
c) should I replace the sensors, or wait and see if they "come back?"
Finally, yes, I know the whole testing procedure for an alternator, but it'll cost about as much as a new altie to buy a good ohm/voltmeter that'll handle it -- my little digital guy would probably explode if I used him... And, like I said, I'm just not overly confident in this area.