Does anyone know how to test a relay box to see if it is faulty. i have an older grand prix and I think I may have one or all that has went bad. Just dont know how to check'em. T.I.V.

It would help to post the year and model Grand Prix.

thanks. It's a 93 2-door w/3.1 multi. Grand Prix

bump

No bumping threads.

What issue are you having that warrants checking relays? If you have the plug-in type you can remove it and check relay coil resistance with a multimeter. Also, as a bench test you can apply 12 volts and a ground to the coil to see if the relay is energizing and deenergizing. Part of the relay or it's primary function is to work as a buffered switch due to current in a circuit. So once the relay is energized you can check to see if the contacts are making using a multimeter. Most relays used by GM have a small illustration on them you can go by.

Otherwise, if you suspect a relay being bad best thing to do is find a similar one by part number in the car and control substitute by switching it out. Also, it helps to use proper documentation like a wiring diagram.