plus, it’s easier to check the codes with the machine. By your car’s way of reading, and 2 other maker’s methods I’ve found, it’s different for each manufacturer.
You should find the diagnostic connector under your hood normally by the fender on the battery side. By just using your test light and a jumper wire, it will tell you what kind of problem you got.
KEY ON ENGINE OFF (KOEO) TEST
- Make sure engine is fully warmed. If in doubt, run engine at 2000 rpm for 2 minutes.2. Turn ignition off and wait 10 seconds for system to shut off. Make sure A/C is off and transmission is in Park (automatic) or Neutral (manual).3. Hook up light and jumper (or a tester if you have one). Turn key to ON (do not start engine). Read the codes.
How to do it?
Example code 23: your test light should flash 2 long consecutive flashes followed by 3 short pulses.
Ford’s common codes for OBD1 (vehicles made before 1995)
taken from here: http://www.extreme-check-engine-light-codes.com/Ford%20OBD1%20Decoder.htm
BMW vehicles obd1 code retrieval
You can get the check engine light codes of BMW vehicles for models made before 1995 using the check engine light. All you need to are:
Turn ignition key to run with engine not running
Depress gas pedal 5 times in wide open throttle (WOT) position within 5 seconds
Read the flash codes in the dash using the code table below.
So, I can look up which vehicle I have and do their method of testing for OBD1, or I can find the diagnostic port and plug a little machine into it and get the codes. Will autozone loan you a test light and/or jumper wire to get the OBD1 codes? They usually read the OBD2 codes for free