OBD engine light on all the time

1995 BUICK REGAL
114,069 MILES • 3.8L • V6 • 2WD • AUTOMATIC
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WAINEE1
  • MEMBER
  • 1 POST
Changed computer and chip.
Changed coils and ignition module.
Changed crank and cam sensor.
Cleaned air flow sensor.


And can't still get the diagnostic meter to hook up to the system. Check engine light stays on and when i put my meter on it, it says can't communicate. Car runs and starts and drives great! Also, no vacuum leaks either. Both o2's have been replaced too...

Again i just can't connect to anything. This is a OBD1 system not a OBDII..

Thanks a bunch.
Aug 29, 2020 at 4:46 AM
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DANNY L
  • ✓Experienced Mechanic
  • 5,648 POSTS
Hello, I'm Danny.

Were you using an OBD1 adapter to retrieve codes? Have you tried using the old school way by connecting a jumper wire to terminal a and b? Here is a tutorial on how to retrieve with a jumper wire:

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Hope this this helps and thanks for using 2CarPros.
Aug 30, 2020 at 6:17 AM
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WAINEE1
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  • 1 POST
First, yes I am using a OBD1 Connector. I have tried several. Second, yes I have jumped the two terminals with no luck!.. The check engine light just stays on.
Sep 11, 2020 at 8:36 AM
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WAINEE1
  • MEMBER
  • 1 POST
I did find out the ground wire has some very low voltage going through for some very strange reason.
Sep 13, 2020 at 6:12 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,325 POSTS
it sounds like you have a bad ground. this guide will help test it:

https://www.2carpros.com/articles/how-to-check-wiring

and

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Please run down these guides and report back.
Sep 13, 2020 at 6:12 AM
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DANNY L
  • ✓Experienced Mechanic
  • 5,648 POSTS
Hello again.
Let us know if you need any wiring diagrams and keep us updated if you find a short or bad ground.Hope this helps and thanks again for using 2CarPros.

Danny-
Sep 16, 2020 at 7:27 AM
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