Nissan Repair: finding out the problem, nissan pickup, circuit tester

Question
the main relay in my 95 nissan pickup stays on all the time, which kills the battery.  when i disconnect the main relay it doesnt kill the battery but let the car start if the relay is unplug.  wha could be causing it?  and how can i fix it

Answer
Hi Paul -

Sorry for the late response. I am in Hawaii, so there is a few hours -

I will need more information on what relay you are speaking of, as it is one of many.

Here is what I think with the information given -

First of all you will need a light type circuit tester. With the ignition off, test each terminal of the suspect relay, one by one. If the light does not come on, the relay is fine, and you will have to look for a battery drain somewhere else, using the same method as described.

If the light comes on, then there is a drain, and you will have to trace that circuit until you find the power source.

Hope this helps
calvin