how could i check the codes on an OBD-I car?

 

You need an OBDI code reader or scan tool. Or the appropriate software and cables for a pc or laptop.

 

what is a cheap on and where can i get it?

 

OBD-I Software:

TTS DataMaster (free download, 20 free uses):
http://www.ttspowersystems.com/

FreeScan (free):
http://www.andywhittaker.com/

pcmcomm (bundled with LT1_Edit software):
http://www.carputing.com/

EFILive V4:
http://store.efilive.com/overview_obdi.aspx

Cable available from:
http://www.akmcables.com/

Scan data interpretation:
http://members.aol.com/InjuneerZZ/ScanMast.htm

For a hardware scanner, Auto Xray made a hand-held scanner that was fairly popular. You can find them used for less than $100. Just be sure NOT to get the Actron "code reader" for $30. Its just a switch that shorts the pins on the ALDL connector, and will only work through the 1993 model year. The box will say it works on your 94, but it won't.

 

My Haynes manual says that you can put a jumper wire from the Diagnostics test port to the ground port, then turn key to on position and get codes. I did try this myself but could not get the codes, it just turned my fans on.
I don't mean to butt in here but I'm having problems also with my '94 OBD1.

 

Using the jumper only works on '93 and backwards. '94 and up require the right tools.

 

...and that's all it will do...

 

Thank you