Phil,

I might be wrong, but I think what is wrong with Kris' car is a bad fuel pump relay. And I think the spare he found is either a faulty fuel pump relay or more likely, not the correct relay.

I have the Volvo green books and it clearly shows the main relay and the fuel pump relay as being different. In fact calling the fuel pump relay the fuel pump relay is a little misleading as it supplies power for both the air slide heater and the control pressure regulator heater as well and there in lies the difference in this relay.

The fuel pump relay Kris needs is not the cheap simple and easily available Bosch relay that is used as the main relay. The cheaper relay is sometimes called a change over relay because as the relay is powered up, one pole of the relay is switch off, while another is switched on. This means that one of the 2 switched poles on a change over relay has power all the time.

On the needed fuel pump relay, the 2 poles are both switched on at the same time when the relay is activated, one pole for the fuel pump and the other pole for the 2 heaters.

And if the spare relay Kris used is indeed a change over relay, then there would be a significant draw as either the fuel pump or the 2 heaters are being powered up all the time.
--
Eric

Hi Performance Automotive Service (formerly OVO or Old Volvos Only)

Torrance, CA 90502