Just a question and comment...you state one terminal is common with the case. Do you mean zero ohms in common with the case? Is there some resistance from this terminal to the case? If so, then these two connections are the 'coil' for the relay and where you would apply batt. power for testing. You can then use your ohm meter to check for N/O or N/C condition on the other terminals. Hint: Know your test equipment! If using an analog ohm meter like a Simpson 260 you must know how to 'zero' the meter to get good ohm readings. Stuart could also be correct, but then that's why they invented fuses. Good luck.
