How can the radio head in my 1997 Mark VIII drain the battery overnight?? The dealer trying to resolve the battery-dead-overnight problem traced it to the radio head, pulled it, and problem stopped. Now no radio. How can the radio drain the battery with the key out?
How can the radio drain the battery??
- Thread starter Kerrigan
- Start date
There could a short within the radio itself or the wiring harness has a loose connection. Maybe the wiring to the radio is grounding out, but not large enough to blow the fuse? Didn't the dealer give you an idea why?
The mechanic at the dealer said he did not know exactly what in the radio causes it, but that he has seen similar problems more than once in the past. The radio has been out for two days and nights now and Friday I'll see if it starts or if the problem is still there. If not, I have a used radio head which is supposed to be good. I'll swap that one in and see what happens. If bad, then it's time to convert to a DIN.
That stuff is actually fairly easy to do yourself. You need a meter that does amps and you remove one terminal on the battery and put the meter between the terminal and the battery wire.
That gives you the current from the battery and you can see whether it's too much from that number. There is a small milliamp draw on a normal setup but it should be quite small.
Then you can start pulling fuses to see which one makes the current draw go away. You are most of the way there when you find it, well where you are now anyway.
You can use the same technique to investigate your radio further but that does need a bit of electronics experience.
That gives you the current from the battery and you can see whether it's too much from that number. There is a small milliamp draw on a normal setup but it should be quite small.
Then you can start pulling fuses to see which one makes the current draw go away. You are most of the way there when you find it, well where you are now anyway.
You can use the same technique to investigate your radio further but that does need a bit of electronics experience.After 3 days sitting it without the radio it started right up. Cleaned the battery posts and clamps again. Ground clamp was fairly lose. Have "good" used radio head I'm going to try next, after checking wire harness and connectors. If no joy, off to the store for an amp clamp. Alarm system doesn't work without radio; antenna must be used to pick up the signal from the fob?
A loose battery connection can cause the battery to drain, as well not charge properly. Are you sure that wasn't the issue?
I'm now wondering the same thing ... gradually losing confidence in the dealer I've been using for years. Last two "repairs" needed to be redone. The old radio head was acting strange lately; popping out of CD mode for no reason ...etc. Going to install the nice used replacement with knobs which latch!