I have the light out right now and the trunk is up as I'm doing work in there. After a few days I noticed the battery was dead, I don't think anything was left on.

------------------
86 SE Convertible 3800sc 4t65e HD.

I haven't had the trunk light in my Formula in years. Never had an issue.

Hmmmm, back to the drawing board then.

------------------
86 SE Convertible 3800sc 4t65e HD.

I'll tell you what kept on draining my battery was my headlight motor. Go feel the motor if its warm its drawing power...good luck

If you have the hood up, not latched, I believe that will drain the battery whether there is a bulb or not.

quote Originally posted by northstar: I'll tell you what kept on draining my battery was my headlight motor. Go feel the motor if its warm its drawing power...good luck

If its what ever under that knob that says "turn" then no it's as cold as it is outside right now(7).

------------------
86 SE Convertible 3800sc 4t65e HD.

I have a similar issue with two fieros here in my shop.

I think its called parasitic drain?

something somewhere is completing a circuit.

time to pull out the circuit tester and check all the connectors and clean the connections.

Put the amp meter in series with the battery positive (or negative) and start pulling fuses. You will find where the problem is. Even a filter capacitor can go bad and draw current. A bad diode in the alternator can also cause a drain. Larry

[This message has been edited by trotterlg (edited 09-24-2013).]

quote Originally posted by trotterlg: Put the amp meter in series with the battery positive (or negative) and start pulling fuses. You will find where the problem is. Even a filter capacitor can go bad and draw current. A bad diode in the alternator can also cause a drain. Larry

Thats going to be my next move.

------------------
86 SE Convertible 3800sc 4t65e HD.

quote Originally posted by Grantman: If you have the hood up, not latched, I believe that will drain the battery whether there is a bulb or not.

Not on my Fieros. I have left the decklid up for over a week in the garage with no bulb in it, no prob starting. Maybe some corrosion is in there allowing juice to pass thru if that is the case.

.

[This message has been edited by infinitewill (edited 01-05-2016).]

quote Originally posted by Grantman: If you have the hood up, not latched, I believe that will drain the battery whether there is a bulb or not.

Not possible. That's like having a lamp in your house with no bulb in it but the light switch is in the ON position, do you think there is electricity flowing to complete the circuit? It's not happening.

I stand corrected X 3

quote Originally posted by TONY_C: Not possible. That's like having a lamp in your house with no bulb in it but the light switch is in the ON position, do you think there is electricity flowing to complete the circuit? It's not happening.

Well....on my 87 GT, two things happen when my rear deck lid is open. Trunk light comes on...and door ajar light comes on. If the bulb out of the trunk light then no power will draw from the trunk light circuit...however if there is something flaky going on with the door ajar light on the dash I suppose that could cause a drain anyway

quote Originally posted by N3M3S1S: I haven't had the trunk light in my Formula in years. Never had an issue.

Same situation. I bought car and it didnt have the trunk light.

Get a Digital Multi Meter (DMM) and check the current draw. Disconnect the negative cable from the battery, put the DMM on amps setting, connect one lead of the DMM to the neg battery terminal and the other to the loose end of the negative cable. Make sure the car is OFF and the doors are closed to prevent a draw from the courtesy lamps. Read the DMM, it should be about 50 mA. if it's higher than that start disconnecting fuses and see if the amperage drops.

I made a simple trunklight switchtimer where its turned off after few seconds, just a few electronic parts, cost you a dollar

quote Originally posted by Tweeder: Yes that's what I'm referring to.

No it won't you have a problem somewhere else. the dash lights won't come on unless the key is in the on position.

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

The cause of my power drain was worn headlight motors.Causeing a massive power drain.Hope it didn't kill the battery. Try disconnecting the single power wire to the right and left headlight motor and see if it retains a charge. If that doesnt work,check your charge gauge on the dash,way low or way high would indicate a bad alternator.

[This message has been edited by James Bond 007 (edited 09-24-2013).]

quote Originally posted by Infinity: I made a simple trunklight switchtimer where its turned off after few seconds, just a few electronic parts, cost you a dollar

Something like that would be cool for dome lights, especially if it faded out like a newer car..

[This message has been edited by 2.5 (edited 09-25-2013).]