Electrical problem-'75 and up
10-19-2003, 03:43 PM
#1
Melting Slicks
Thread Starter
Electrical problem-'75 and up
My 75 has a dead battery if it sits for over a day. Car was fine up until about a month ago. Replaced it last week and still won't start this morning.
Here are the new symptoms that I noticed this morning.
When I got the car jump started,
1. Tach (electronic) was registering about twice as fast as car was going (i.e. idle at 1200 when I know it wasn't any different that before)
2. When I try to raise the windows (power) they don't move but tach slowly goes higher until I let off the switch.
3. No headlights (will raise- vacuum) but not light
4 Battery gauge is registering in negative at idle, but slight positve at higher rpm (this is usually normal for this car)
Most importantly- when shutting off the car after running for a while, DEAD- not even enough power to sound the key buzzer.
HELP! What is wrong? Is there just a fuse out? I did replace the tach circuit board about 2 years ago. Has a new starter in last 2 years and alternator last year.
[Modified by Rich's75, 3:50 PM 10/19/2003]
Here are the new symptoms that I noticed this morning.
When I got the car jump started,
1. Tach (electronic) was registering about twice as fast as car was going (i.e. idle at 1200 when I know it wasn't any different that before)
2. When I try to raise the windows (power) they don't move but tach slowly goes higher until I let off the switch.
3. No headlights (will raise- vacuum) but not light
4 Battery gauge is registering in negative at idle, but slight positve at higher rpm (this is usually normal for this car)
Most importantly- when shutting off the car after running for a while, DEAD- not even enough power to sound the key buzzer.
HELP! What is wrong? Is there just a fuse out? I did replace the tach circuit board about 2 years ago. Has a new starter in last 2 years and alternator last year.
[Modified by Rich's75, 3:50 PM 10/19/2003]
10-19-2003, 04:55 PM
#2
Melting Slicks
Thread Starter
Re: Electrical problem-'75 and up (Rich's75)
Ok now I jumped the car again with the Tach disconnected. Power windows went up and down, headlights would light up and after hooking the tach back up (while the car is running), it was working fine. Though......
After letting the car run for a couple of minutes, it still wouldn't start on its own (dead battery).
I am starting to lean towards a bad alternator again.
Anyone have any other ideas, don't hesitate to speak up.
Will test alternator and get back to you guys, but other than that I am stumped.
After letting the car run for a couple of minutes, it still wouldn't start on its own (dead battery).
I am starting to lean towards a bad alternator again.
Anyone have any other ideas, don't hesitate to speak up.
Will test alternator and get back to you guys, but other than that I am stumped.
10-19-2003, 07:20 PM
#3
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Re: Electrical problem-'75 and up (Rich's75)
Pull the batt & alt for testing at a local auto parts. Could be one or both. That way you can be sure of their condition.
Seeing abnormal electrical functions when there isn't sufficient voltage is not unusual. You should see what the late model vehicles do when the proper voltage is lacking! :crazy:
When the above is done and reinst, check your battery for a 'static draw'. Could be something is pulling current when at rest.
Read these for info on checking........ http://forums.corvetteforum.com/zerothread?id=196205
Search archives with "draw" as keyword for more info.
Good Luck :chevy
Seeing abnormal electrical functions when there isn't sufficient voltage is not unusual. You should see what the late model vehicles do when the proper voltage is lacking! :crazy:
When the above is done and reinst, check your battery for a 'static draw'. Could be something is pulling current when at rest.
Read these for info on checking........ http://forums.corvetteforum.com/zerothread?id=196205
Search archives with "draw" as keyword for more info.
Good Luck :chevy
10-19-2003, 08:46 PM
#4
Melting Slicks
Thread Starter
Re: Electrical problem-'75 and up (ROD NOCK)
Thanks Rod
Took the alternator off and tested. It was puting out 13 volts but only about 12 Amps. Definately sounded like the bearing were going out too.
Replaced it and everything seems fine now. Battery gauge is showing +40 for over an hour afterwards on a 60 mile drive.
That was different to see the tach acting like it did though. That kinda threw me for awhile.
Took the alternator off and tested. It was puting out 13 volts but only about 12 Amps. Definately sounded like the bearing were going out too.
Replaced it and everything seems fine now. Battery gauge is showing +40 for over an hour afterwards on a 60 mile drive.
That was different to see the tach acting like it did though. That kinda threw me for awhile.