I hope for your sake that your car can take one of the new Bosch upgrade Relay Kits that run about $100... otherwise you could be looking at over $200 for a replacement relay.

IF you are facing an expensive relay replacement, another option is to change over to a much simpler relay system that is far less expensive and more reliable. With such you would manually operate the glow plugs using either a spring loaded or push button switch on/under the dash. It uses an very simple and thus reliable relay. Let us know if you want more info on this upgrade to an old style system.

On a lark I recommend you remove the fuse on your relay and then re-install it. This can some of the time show that your fuse has "embrittlement" and needs replacement. It can cause your relay to act up and nor work also.

Good luck,
Sam