OBD2 connecter to OBD1 connector?

[blindeyed]

For those of you with the OBD 1.5 setup who have the OBD2 connectors but have an OBD1 system.. Has anyone swapped out the OBD2 connector for an OBD1 connector? Just curious if it's possible, it would make for scanning codes be a little easier I would imagine. I'm not even going to bother if it's a really involved process. Currently I'm doing shoebox's method here:
http://shbox.com/1/xraycable.jpg

Would just rather have an OBD1 connector, would make things simpler.

[chevy42083]

I don't see it being difficult, it's just 3 wires, right?

I thought most scanners would read through the OBDII plug... but I guess a lower end scanner may only have OBDI hardware.

When I ordered my laptop cable I just stuck with gold pins... so I could use it in either plug.

[Stroked96Bowtie]

Ive got the same setup...OBDI with an OBDII connector...havent had any problems pulling codes with it.

[hartman]

did anyone decide how to do this and what wires go where?

[bad88camaro]

ill let you know tomarrow. ill get a schamic from all data and i let you know

[hartman]

did you ever get it?

[MEAN LT1]

Why would you do this swap. Just get a obd2 connector.

[hartman]

so you dont have to use the 2 wires everytime just to read codes so did anyone ever figure it out?

[meissen]

Sorry for not responding sooner - I just saw this thread. YES it is certainly possible to do this swap! I actually did the opposite - I had a 1994 OBD1 plug and wanted to change to a 1995 OBD2 plug because the cable I have is OBD2.

On the OBD1 plug you only have a few wires to worry about. Just take the pins out of the OBD2 or chop off the wires if you have an OBD1 with wires still attached and solder the wires together. All you're really doing by converting from one plug to another is changing the plug itself - no harm there at all.

With an OBD2, you're going to have 12v+ (orange or red, can't remember), a couple grounds (one solid black and one black/white), data serial (tan), diagnostic enable (white/black), and program input for keyless entry (black/white).

On the OBD1 you will have ground (black/white), program input for keyless entry (black/white), data serial (tan), and diagnostic enable (white/black).

The most confusing issue you will run into is the two black/white wires. One has a thicker white stripe than the other. One is ground to the instrument cluster, the other is the input for the keyless entry programming.

For the '95 OBD plug, the black/white for the keyless entry is cavity 8.
http://shbox.com/1/1995_pcm1.jpg

If all OBD1 (93 and 94) are the same, then the black/white in cavity 8 is going to go into the bottom LEFT cavity on the OBD1 plug.

Basically, to sum it up:


Programming Input for Keyless Entry Black/White - OBD2 Cavity 8 to OBD1 Cavity G
Diagnostic Enable White/Black - OBD2 Cavity 6 to OBD1 Cavity B
Data Serial Tan - OBD2 Cavity 9 to OBD1 Cavity M
Ground to I/P Black/White - OBD2 Cavity 5 to OBD1 Cavity E or A - I can't remember which.

Where OBD1 plug cavities:

F E D C B A
G H I J K L M

Hope that helps! :D