Chrysler Repair: 1992 Fifth Avenue wont start Part 4, amp fuse, powertrain control


Question
QUESTION: Hi Roland,

    The last time the light was on was a few days ago when the original condition was present.  The light would come on very briefly or not as briefly, it varied widely.  The light and the pump would run concurrently.  When the light stayed on past the end of the pump cycle the engine would start.  Sometimes it would run for a few minutes, sometimes for a few seconds.  As time has passed it has gotten progressively worse, and now even with the set light off, the check engine light and the fuel pump are not running at all.  Thanks for all the time you've spent on this----------Andy

ANSWER: But which type of cluster is it? And did you see my add on to the last answer?

---------- FOLLOW-UP ----------

QUESTION: Hi Roland,

    I'm sorry, this car has a mechanical cluster.  And I went back and looked at your follow up, thank you very much!!-------Andy

Answer
Then with that cluster we have a hard-wired situation (not a digital communication, hooray) between the powertrain controller and the cluster. Both the fuel pump and the powertrain control module need to have 12v from the ignition switch in the start and the run position of the key which comes out of the switch on a dark blue wire directly going to the fuel pump and the engine controller. The pcm has to have power to turn on the fuel pump and to light the check engine bulb. The source of the voltage is the 40 amp fuse in the powerbox labelled 'ignition system' so check that.
So we are back to where this all began, as I recall, so verify whether you have voltage at the inboard pin socket of the ASD relay as well at at the dark blue wire pin 9 of the PCM's 60-pin plug (probe the wire with a pin, attach your voltmeter leads to the pin and to ground), when you have key in both the Start and Run positions.
It is also possible that the check engine bulb is burned out so jump 12v to the black/pink wire at pin 32 of the pcm plug by means of a pin poked in that wire and then jump from the + post of the battery to the pin to see if the check engine light goes on or not (have the key 'off' for this test).
I will be unavailable all day Sunday, so either continue today or on Monday.