Has anybody removed and replaced a thermal time switch on a CI engine [in my case the B23]? I think I can just see something that looks like an electrical connection emanating from the block just below number four intake manifold pipe [looking at the engine from the top]. It was described by the website on Volvo fuel injection systems as being 'below number four injector'. Haynes says that one should partially drop some coolant and then remove it. No reference to its position on the engine.

I haven't lifted the car yet and had a look at the job from beneath. Would this be the way to go? And what has to be removed to clear a way to it?

I am getting no spray from the cold start injector and no twelve volt reading after the engine has started. This points to the thermal switch as the culprit according to the manual.