Alternator Fusible Link

[spudea]

What does this link do? Does it power all the accessories? Well I've been living with a drain on my battery when I turn the car off for a couple months now. If I remove that link the battery isn't drained. But if I leave it, the battery will be dead in like 12 hours. I'm about tired of having to remove that wire everytime I stop and putting it back on everytime I leave and having to reconfigure my stereo everytime too! I have a multimeter and with that wire connected I tryed to measure the amps running through it with the car off. I read 0. So this wire must provide power to the alternator? Then all the accesories draw their power through the alternator? But if there was a drain through the alternator wouldn't it still show up on that wire? Thanks for all your contributions.

[Bambikiller240]

What year Z is this on? My 72 only has one fusible link which connectsd to the starter.

[spudea]

oops sorry. '78 280z

[ezzzzzzz]

The link is a wire that acts as a fuse. It will burn up and break the circuit before major meltdown and/or fires occur should a direct short happen the the wiring harness. It is not your problem. With everything turned off and key removed, lift the ground cable off the battery. Place an ammeter (a digital multimeter set to read <100 milliamps) between the ground cable and and the ground post of the battery. There should be mimimal amperage drawn (<60 milliamps). If you have more current draw than this, or you need to set the mulitmeter to a higher scale to read the current draw, then something is wrong. With the meter connected, pull one fuse at a time to until the current draw drops to <60 milliamps or at least very close to this. The fuse pulled that caused the drop is the culprit circuit. You'll need to investigate to determine what is causing the excess draw. I'm thinking that you're running an amp that is possibly hot-wired (not powered by stereo or ignition) that is causing the battery to drain. Straight shorts cause fuses to blow or melt the fusible link. I had a similar problem on my old land rover. It turned out to be the relay for the electric cooling fan. It would hang up but not turn on the fan motor killing the battery in mere hours. It took me two weeks to finally resolve that one. :lick:

[spudea]

Ok thank you very much! I should of tested this long ago. Power draw was close to 1 amp! I started pulling fuses/links and kept testing. I don't have a fuse box cover. Can anyone who has a '78 Z tell me what fuse is in the right column, second from the top? I took that fuse out and the draw went down to ~.335 amps. Thats 335milliamps right? So thats still too high?

[spudea]

All fuses, includeing the stereo amp fuse, removed and all links removed except for the alternator fusible link, draw is still ~.335. If I remove the alternator fusible link it drops to 0. So do I have an excessive draw after the alternator? I have an aftermarket stereo and 50watt amp.

EDIT: I also have a 12disc cd changer.

[ezzzzzzz]

.335 is fine! A battery would last for days on end with that minimal draw. I don't know for sure about that fuse but in my 240z that is the right side headlight circuit. Maybe someone else can pipe in with the real info?

[spudea]

Awesome! Now I can set my clock and stereo for last time hopefully I posted on zcar.com about that fuse and it is the Dome light fuse. Good thing it isn't anything serious. But now at night it will be a little hard to see. An axe murderer could hide in my car and I would not realize it untill it was too late Thanks again!