I have been trying to get my Jimmy to be checked out via OBD2, but the Check engine light does not come on when the vehicle is started and the OBD2 tester wont read it. I presume there is a bad wire somewhere, but which one and where I can find it and get it fixed??? Please help!

 

What year is your truck? My 95 service engine light did not work either until I removed the piece of tape covering it on the gauge cluster. These lights do burn out. Very rarely but they do. Even then the obd2 will not read codes. You may need a obd1 code reader to get the codes if it is a 95.

 

if cigarette lighter fuse is out you wont be able to read the codes.

 

Its a 95. and the cigarette lighter does work

 

Where is this tape on the gauge cluster???

 

The previous owner removed the an o2 sensor and placed a piece of tape over the service engine light. It is still on every time I run the truck but it runs fine. Mine is a 95 and has the obd receptacle under the dash but only a scan tool that is obd1 functional will read the codes. The parts stores don't usually have scan tools that read obd1. Check the cig/radio fuse if not that find a shop that has the obd1 capable scan tool.