Nisan Stanza, 87, Battery running down? Clicking sound from EGI relay? Nissan mechanic any ideas?

Question

1987 Nissan Stanza, Auto matic trans, GXE, O.V. 5FCF9? (not familiar with these engines).. any way... a neighbor kid is trying to figure out why his battery keeps draining. We checked every light-trunk, glove box all shut off. Found main disc. switch in glove box and checked to assure battery isnt grounding to hood top. Also had Alt. tested which was good.

In the fuse box under hood, passenger side, the EGI Relay (green box) is making a quick clicking sound after the engine is shut down and key removed like the contacts are opening and closing sending power somewhere? This Relay/fuse was replaced and still clicking once shut down.

Also, down by the dist. cap, too the right there is a vacuum unit with 12 volt power going to it that will momentarily activate and shut off after the car is off and sitting. It has a vacuum line that runs top of engine too another motor that I believe deals with the fuel valve... ?

something is draining the battery and have no idea.

Answer 1

Alternator might charge OK but drain the battery when sitting (bad diode) Connect a headlight bulb or brake light bulb between the battery - and Negative clamp removed from the battery in series if the car had draw/drain the light will light up. Start with the gray two wire plug on the alternator yes the one you broke the plastic tab off of. light still on? Next carefully remove the big battery wire from the alternator. Light go out? And Start removing under hood fuses one at a time replacing as you go until you find which circuit is draining the battery. After 1994 my computer does not have wiring diagrams so when you find the fuse you will have to find paper Nissan service manual to see what all that fuse powers up. Most times it is the alternator draining the battery until the egi relay starts clicking. Recharge the battery or replace the battery after you fixed the drain. Drawing the battery down slow kills the plates inside.

Answer 2

Sounds like a wire has shorted somewhere and is allowing power to leak where it shouldn't go.
You will need wiring diagram. Most libraries have auto repair books that have those. Not familiar with that particular car.

good luck