Now that the fuel pump circuit is fixed, and the car starts right up, I'm starting the process of investigating why the a coolant warning light on the dash has tripped on in my 85 xj6.

Currently: I have coolant in the reservoir, and am assuming (hoping, really) that this is an electrical lead problem.

I've read the helpful post here: https://www.jaguarforums.com/forum/x...t-light-56901/ but did have a few 'what next' questions:

First off, is there any way to test the coolant sensor?
Second: How about the transmitter under the dash (any way to give it a signal it should interpret as 'okay' so I can see if the light goes off)?

 

Wow, that was actually a quick fix -- for posterity it was indeed a loose wire I'd missed the first time.

 

Result.
I always like the zero cost fixes the best.

Changed your thread title by adding 'RESOLVED' to show it's fixed.

Graham

 

where was the loose wire? at the coolant resevoir tank?

 

Yes -- re-seated it and the light ceased firing (I suppose it could be burnt out )

 

if you pull/pry the indicator lights faceplate, (the black plastic plate between the speedo and tacho), there are spare bulbs there, because some idiot lights are not used in the Series 3, 6-cylinder XJ. just pull the plate with your fingernails.