[xj40] cursed A/C; I jinxed myself

List,

You know, it actually crossed my mind this afternoon that maybe I shouldn’t
say that I haven’t had any major problems since I fixed the A/C. I didn’t
want to jinx myself. Well, on the drive home this afternoon, I smelled
something electrical burning. A few minutes later, the A/C cut off, just
like it did before.

I am trying to avoid the knee-jerk reaction of driving the car off of a
cliff and claiming the insurance pay-off. In reality, I need to either
figure out why its blowing ECUs or at least prevent it from blowing the next
one. I can’t really afford to buy another used ECU every month or so. I
don’t think there’s any way to dream what the problem is, so what do you
think about this?

If I test this ECU out and the diode is blown, I am either getting an
overvolt on the power from the diode, or a reverse power surge back through
the recirc circuit, which has the diode at the other end of it. Therefore,
I’m tempted to put a fuse in-line on the LGO from the diode and the SU out
to the recirc. I would have to make it pretty low amperage to protect the
ECU, but if one of them blew, it would be a hint as to what was going on.
Does anyone think that’s a good idea? Is there anything else I could or
should do to protect the ECU? I can buy another one, but if the car is
going to blow ECUs with regularity, I will have to get rid of it.

Regards,
Dan
'91 VDP, cursed A/C