5 replies to this topic

[Nathan]

CAR: 1997 855R with stock SC-815 head unit and amp.

PROBLEM: I have been getting dead battery lately if I'm not driving the car for a week or so. I did some testing with a harbor freight amp tester (http://www.harborfre...ster-67724.html) and found that I am drawing 1 to 1.1 amps through fuse #6 (radio/amlifier) when everything is shut off. I pulled the head unit and disconnected the two wiring connectors, and the amp draw disappeared. When I reconnected the wiring to the radio the amp draw reappeared.

My first thought is that the radio is bad, but if I'm going to replace the head unit I would like to be sure that that it is the problem first.

Any suggestions on what to check next, or where to look?
A good wiring diagram would help also to see if anything else is on the same circuit.

Thanks,
Nathan

[BEJinFBK]

Diagrams are available here:
http://www.matthewsv...iring-diagrams/

[(_8*(l)Homer]

I'd pull the radio out and see if you still have the drain to diagnose.

[Bah]

If that multimeter is worth a sh*t, and your drawing 1A, your car battery will be dead overnight lol.

One of the radio circuits includes power locks and all sorts of things, not sure if 6 is the main one or not.

I would pull the radio if you have the code, and see if the draw goes away. If it does, you've narrowed it down to either the Amp or the stock unit...both easy to fix. Give it a shot and get back.

[Bah]

Just re-read it all...if you go back up the harness, you can disconnect the amp. It's wrapped up in sticky fluffy tape. You'll see it. Unplug it, and connect the headunit up directly. It's possible the amp is not turning off as expected. Either way, i ditched the Amp, it couldn't handle the 2-ohm loads [even though the speakers are in series i believe...]

[Nathan]

OK, thanks for the responses. UnfortunatelyI have been sick this week. Hopefully I will be back at it this weekend.

As for the battery and the 1 amp load... I agree that it may be high now that I hink of it. Most batteries have a minimun capacity of 45 amp hours, (and I generally put in the biggest one that will fit) so while I agree that it may not last a week, a 1 amp load shouldn't kill the battery too quickly. After all most headlights are 60 watts each for a total load of 120 watts. 120 watts / 12 volts =10 amps... which explains why batteries die after a few hours with the lights on.

Thanks again, and thanks for the link to the wiring diagrams.
Nathan