while replacing the spark plugs I noticed a relay beside the battery [and positive link and voltage reg] - I clipped it off for a peek and the base had disintegrated and was only remotely held in place by the spades into the socket

an inspection of wiring as well as wiring diag says it must be for headlight wipers [which I had removed long ago] so it does not matter if it still works or not

plus it is not a simple on-off relay but same as one of the fuel pump relays ie SPDT [ie a 2 way switch] ie terminals 87 AND 87A, a very rare beast to buy in my experience - seems it was needed because of some cunning operation of these wipers with the washers and screen wipers but I cant quite see WHAT, but dont matter anyway

as far as I know all other relays are inside the car - so looks like not smart design to have delicate semi sealed devices in heat and moisture of engine [for sure I had to replace the voltage regulator which had also rusted up and ceased to regulate]

I was quoted $40 special order from Bosch for this "changeover" relay so I will just trust that the same one on the fuel pump keeps going

In any case on my 264 I have installed a bypass switch which will keep the pumps running in an emergency if relay fails

But this is good discovery for others ie if car stops dead because the SPDT relay on pumps stops, you HAVE a spare one on the the wipers for the headlights at least to get you home