Electrical Problem - Where to start???
#1
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Electrical Problem - Where to start???
I have had my 1986 for about 3 months now. These issues have all started cropping up in the last couple of weeks.
1. Radio shuts off occasionally while driving (becoming more frequent).
2. Power antenna has broken from all the ups and downs, chopped green wire to antenna motor to stop the constant running.
3. Car now takes multiple (5-6) tries to start, started two weeks ago, getting worse.
4. Windshield wiper switch works initially, but won't change settings after on, won't always shut off.
5. Dashboard flickers intermittently (getting much worse) causing radio to shut off, and most recently causing reduction in power from engine during flickering.
6. Turn signals cause instrument panel to pulse.
OK, that being said, here are the caveats.
This does not seem to be associated with turning, bumps, or other agitation, it happens on smooth roads going straight just as often and is becoming much more frequent.
When the flickering and power loss starts, and I apply my brakes, it stops momentarily, usually. If I have my brakes on when I initially turn on the wipers, AND apply them when changing the settings, it works, usually. If I have my brakes applied when I initially turn the ignition key on, it starts first or second try, usually.
I am an electronic technician, so I recognize that this is 95% certainly a ground issue. I also realize that ground issues are very difficult to isolate. I am hoping that someone has run across something similar.
Is there a component(s) that would cause this, as opposed to a broken wire or short? Like I mentioned, the fact that movement of the car has nothing to do with it, I am inclined to think there may be a module going bad somewhere.
ANY and ALL help is deeply appreciated.
Chris
1. Radio shuts off occasionally while driving (becoming more frequent).
2. Power antenna has broken from all the ups and downs, chopped green wire to antenna motor to stop the constant running.
3. Car now takes multiple (5-6) tries to start, started two weeks ago, getting worse.
4. Windshield wiper switch works initially, but won't change settings after on, won't always shut off.
5. Dashboard flickers intermittently (getting much worse) causing radio to shut off, and most recently causing reduction in power from engine during flickering.
6. Turn signals cause instrument panel to pulse.
OK, that being said, here are the caveats.
This does not seem to be associated with turning, bumps, or other agitation, it happens on smooth roads going straight just as often and is becoming much more frequent.
When the flickering and power loss starts, and I apply my brakes, it stops momentarily, usually. If I have my brakes on when I initially turn on the wipers, AND apply them when changing the settings, it works, usually. If I have my brakes applied when I initially turn the ignition key on, it starts first or second try, usually.
I am an electronic technician, so I recognize that this is 95% certainly a ground issue. I also realize that ground issues are very difficult to isolate. I am hoping that someone has run across something similar.
Is there a component(s) that would cause this, as opposed to a broken wire or short? Like I mentioned, the fact that movement of the car has nothing to do with it, I am inclined to think there may be a module going bad somewhere.
ANY and ALL help is deeply appreciated.
Chris
#2
Race Director
Chris,
Since you're an ELECTRONICS technician, and you mentioned grounds, I'm going to assume you've pulled out the manual and started checking the chassis grounds...
However, I have to ask; have you started checking/cleaning the chassis grounds?
MIke
Since you're an ELECTRONICS technician, and you mentioned grounds, I'm going to assume you've pulled out the manual and started checking the chassis grounds...
However, I have to ask; have you started checking/cleaning the chassis grounds?
MIke
#3
First off dunno why you cut a wire instead of pulling the fuse.
Check your grounds but you might also want to check your battery/alternator. You may have low or drifting voltage due to your atl going out ...bad brushes and a weak battery. These cars depend on a stable voltage and go nuts if it's off. Then as mentioned grounds. That could also be your starting problem. When you solve your electrical problems and are still having problems starting read this thread started by Lee about how he solved his starting problem.
http://forums.corvetteforum.com/c4-t...nk-solved.html
Check your grounds but you might also want to check your battery/alternator. You may have low or drifting voltage due to your atl going out ...bad brushes and a weak battery. These cars depend on a stable voltage and go nuts if it's off. Then as mentioned grounds. That could also be your starting problem. When you solve your electrical problems and are still having problems starting read this thread started by Lee about how he solved his starting problem.
http://forums.corvetteforum.com/c4-t...nk-solved.html
#4
Melting Slicks
#5
Race Director
Here are the grounds on an '86:
http://home.earthlink.net/~cliff_har...s/grounds.html
Click on the pictures to enlarge them. The most likely suspect in your scenario is the ground on the side of the block above the oil filter. Many instrument panel and ECM grounds connect there.
http://home.earthlink.net/~cliff_har...s/grounds.html
Click on the pictures to enlarge them. The most likely suspect in your scenario is the ground on the side of the block above the oil filter. Many instrument panel and ECM grounds connect there.
#6
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Cliff - Thank you for the diagrams. I haven't had to do any troubleshooting yet, so I don't have the manuals. Looks like it's that time!
Everyone else, thanks for the great suggestions. I haven't had time to address this problem yet but will start tonight. I'll let you know what I find!
"First off dunno why you cut a wire instead of pulling the fuse." ----- I never claimed to be a genius. Thanks for confirming that I am not.
Chris
Everyone else, thanks for the great suggestions. I haven't had time to address this problem yet but will start tonight. I'll let you know what I find!
"First off dunno why you cut a wire instead of pulling the fuse." ----- I never claimed to be a genius. Thanks for confirming that I am not.
Chris
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Progress Report
I have checked, cleaned, tightened all of the ground locations except for G104 (the one on the LH Rear of the motor) which seems the most likely culprit. I am going to run it up on a friends lift later today to check that one. Will post results later.
#9
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Resolved
There was a ground location that wasn't on the list. Behind the battery box near the firewall. All problems have been resolved. Thank you for everyone's input.
Chris
Chris