There is a general problem with slip on connectors (non-soldered
connectors)  applies to all plugs and relay panels.  A problem colloquially
referred to as incipent progressive corrosion can affect all these
connections.  Over time, corrosion will grow at the contact interfaces and
intrude on the viability.

If you imagine a playing card and imagine a mouse chewing away at the
periphery of the card you can see that as the size of the card is reduced
the area is likewise reduced.  Now for contacts such as the slip-on spade
connectors the same applies.  As corrosion attacks the interface the current
carrying portion is reduced in area thereby increasing the impedance at that
interface.  The increased resistance causes heat to be dissipated at the
interface and a voltage drop.  (actually in reverse but not essential to the
explanation)   Once the voltage drop is sufficient to drop below the
threshold of activation of the thingy that depends on 11VDC to work at all,
the symptoms begin to appear, intermittantly at first causing the whzzat
response until the intended operation fails.

To bell the cat here, occasionally and at your leisure, unplug and re-seat
all the connections.  Paying special attention to the ground stars, you may
discover that the wiping motion of the removal and replacement will restore
youth and vigor to your aging road diva,  well perhaps not youth.  If you
keep a notebook of what you 'serviced' and what symptoms were no longer in
evidence after each service you can get a pretty good idea of how
degradadation and decrepitation and old age affects your ride.  Make the
notes on a copy of the trace diagram so you have a measure of what was done
and what results were observed.

The lady would appreciate the attention and perhaps bestow a reward or two.

Or you could just sell out, buy a toyota, and fade to grey.

There is much information available on these processes should you require
authentification.

Pensionerd.  Still trying to evade entropy