Re: how to do a self diagnosis test on a 93 eb?
Connector under dash on driver's side near fuse panel.
Relevant pins grouped as follows
- - - - - -
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Connect high impedance test lamp or meter to "C" and to 12 volts.
With ignition off bridge A and B with a looping cord.
Turn ignition on
After a few initial flashes fault codes displayed, and the repeated. You really need a list of them to interpret them correctly. Gregory's have them, unless anyone else can link you to them.
If you get code "11" there are no definite faults.
See how you go.