1979-1993 & 94 Conv [Subscribe to Daily Digest] |
 | [Main C900 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: power windows and alternator Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Wed, 8 Jan 2003 12:51:18
In Reply to: power windows and alternator, nt moore, Wed, 8 Jan 2003 12:40:45 Members do not see ads below this line. - Help Keep This Site Online - Signup |
With the car off and no load, you should see around 12.5 volts or so on the battery. With the engine running, you should see around 13.5 volts on the battery - that shows the alternator is working. That voltage can vary a lot, depending on what electrical loads there are, how the alternator is doing, even how cold it is - the voltage regulator is temperature compensated. Basically between 13.0 and 14.2 is OK., but mid 13 volts is nice.
You may have a battery cable problem or other grounding problem. Try this - start the car, and use the voltmeter to measure between the negative battery post and the clamp on the negative post. Note that voltage. Also measure from the battery post to a chassis contact. Now, do the same for the positive battery post and the clamp. Now, turn the headlights on, blower to max, rear defroster on, seat heaters on. Measure again.
If you see more than about 0.05 volts or so between the negative post and the negative clamp, or from the negative post to the chassis, remove the connections and clean them. Same for the positive.
If that all measures out OK, measure the voltage at the battery (engine running) while someone moves the windows up and down. Windows are a big load, and it's reasonable for the voltage to drop a little. But if the voltage at the battery drops more than about 0.4 volts or so, or if the voltage drops to less than about 12.8 or so, the alternator may be getting tired.
Yes, you can lubricate the window tracks. But believe it or not, it may be the window switches. The switches build up carbon on the contacts, and this produces a voltage drop, so the motor runs slower. But a slower running motor actually can pull more current.
posted by 192.249....
, Wed, 8 Jan 2003 12:51:18 <-- Viewing This Message
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
