New! Help! Battery Drain

[TheOSU32]

So I've just gotten my girlfriends 97 Explorer 5.0 up and running after sitting for 2 years, but over the past 2 weeks I've discovered it's got a battery drain. Has been dying frequently and even over a 10 hour period.

Battery is 6 mo. New, just got tested and recharged at AutoZone. So not the issue.

Using multimeter and determined alternator also good.

Used multimeter to perform battery drain test on negative side, this is where things got interesting. Noticed always about a .7 draw immediately, but would quickly kick up to over 1 once the underhood bulb turned on. I unplugged the number 27 fuse to turn off this bulb and then got a reading of .25, still high, but much less then before. I then continued the draw test pulling fuses (all without fuse 27 so the bulb wouldn't kick on) until I pulled fuse 25 (speedometer/GEM module) and it went down to .01 draw. I then plugged back in fuse 27 but not 25 and I still only got a .01 reading, and underhood lamp didn't turn on. So I assume that is where my draw is.

Now here is where I need help, is the draw in 27 and 25 related? Does it even matter since the draw completely went away once only fuse 25 was pulled?

I'm thinking that the draw is from a bad GEM module not the speedometer, and this might also play into fuse 27. And that it needs to be replaced. BUT how can I be sure? Is there a way to test speedometer versus gem? I want to fix this myself and use junkyard parts if possible, however I don't want to go pull a GEM module for the junkyard if it's not the problem.

So I'm looking for some confirmation of my thinking / guidance in this process. All help is appreciated!

 

[1998Exp]

How long did you wait to read the meter? It takes a few minutes for the GEM to go to sleep and deactivate all internal consumption. You need to wait a few minutes after closing all doors before the measurement is valid.

So I've just gotten my girlfriends 97 Explorer 5.0 up and running after sitting for 2 years, but over the past 2 weeks I've discovered it's got a battery drain. Has been dying frequently and even over a 10 hour period.

Used multimeter to perform battery drain test on negative side, this is where things got interesting. Noticed always about a .7 draw immediately, but would quickly kick up to over 1 once the underhood bulb turned on. I unplugged the number 27 fuse to turn off this bulb and then got a reading of .25, still high, but much less then before. I then continued the draw test pulling fuses (all without fuse 27 so the bulb wouldn't kick on) until I pulled fuse 25 (speedometer/GEM module) and it went down to .01 draw. I then plugged back in fuse 27 but not 25 and I still only got a .01 reading, and underhood lamp didn't turn on. So I assume that is where my draw is.

 

[bobflood]

Some suggestions:
- Remove underhood bulb instead of pulling fuse - you are also eliminating other things on the fuse which may cause the problem.
- Tape down the pin sensor for the hood so truck thinks hood is closed.
- I believe that your steady state draw after everything goes to sleep should be .05 amps or less.
Good luck.

 

[TheOSU32]

Repeated test hour after car turned off, and removing bulb. Still got draw of about .7-.8. All was fixed when pulling fuse 25. Speedometer/GEM. Suggestions or thought?


OTHER ISSUE. Car has been very unreliable on starts, even with us now unhooking the battery every time we stop. Battery has been confirmed good, and alternator appeared fine using multimeter test with car running. Terminals have also been recently replaced. My only thoughts are battery cable or starter. Car does make a lot of turning sound so does not seem like starter to me, but are there any tests I can do to isolate the starting issue. Which may be more vital at the moment.

Thanks again.

 

[SWIGIN]

I'd start with new cables and see what that does.

My 98 acted similar when I first got it and it was a bad battery ground wire.

 

[TheOSU32]

So I'm now more confident that the starting issue is a battery cable problem, as this morning it wouldn't want to start and just jiggling the cables a bit made it start right away. Specifically the positive side. So the question becomes what is the process to replace the battery cables? Can anyone help explain here the process or send me a link to one? Some sites on the internet make it seems very simple while others seem to say its worth it to just take it in an have it done. I believe its just the positive that needs to done, and perhaps i just need to strip the wires a little more and put more cable into the new terminal.


Also still would love opinions on my fuse 25 problem. If anyone has idea how to isolate Speedometer versus GEM or has thoughts on this I would appreciate it.

 

[bobflood]

Re the positive battery cable:
Strip the insulation down a couple of inches and see if it is corroded and, if so, how far. You may be able to cut out the corroded piece and still have enough slack to reach the terminal clip. That worked a couple of years ago for me. If not, try to source a new battery cable from the internet and replace it.
Re the fuse 25 issue:
Wiring diagram confirms that fuse 25 powers only the IC and the GEM. The GEM is probably the easier of the two things to unplug. I just replaced mine due to issues with the power windows, battery delay, etc. A used one cost me $20 on the internet; just make sure that you match up the numbers on the GEM.

Pull out the radio using the tools that slide into the two pair of holes in the front of it, unplug it and set it aside. The GEM is a black box on the left side of the opening. According to the wiring diagram there are four plugs into the GEM; fuse 25 powers terminals 5 and 11 in connector C283. As I remember it, the connectors are at least three different colors - white, gray and black - but the wiring diagram doesn't give the connector color. Connector 283 is not the smallest nor the largest connector; the first terminal has no wire and the last one has a black ground wire. The two power wires on terminals 5 and 11 are both white w a yellow stripe. If you can identify that connector, disconnect it and see if the drain goes away. Best to disconnect the plugs while the GEM is still mounted if you can.

When you remove the GEM, there is a screw on the bottom that screws sideways into the bracket. Remove that screw and slide the GEM down until it comes off the top of the bracket. Again, disconnect as many of the plugs as you can before you try to remove it.

Good luck.