1999 Gt 0.250a Parasitic Draw From Gem Module/radio

Discussion in 'SN95 4.6L Mustang Tech' started by Codyp1814, Feb 23, 2014.

  1. Hi everyone, I recently bought 1999 GT and have noticed the battery has been dying every 4-5 days if I dont drive it. I've located the cause of the draw through fuse #27 (the radio) and fuse #39 (the GEM module). They both draw about 0.13A. The radio is the stock one, I'll probably figure it out.

    The GEM module however is very confusing. I read about this one guy who disconnected the connector closest to the door and that stopped the draw. I did the same, and the draw did not change at all, nor did unplugging the other 2 connectors next to it either. I noticed there are 2 more connectors connected to the GEM closer to the firewall, but am unsure how to disconnect them, or if disconnecting them will change anything.

    Anybody else experience this? Is the GEM module most likely bad?

  2. Try checking your alternator or replacing it before the gem. I had a similar issue on my sons 97 gt. We swap a complete drivetrain/harness/emission stuff over from an 01 cobra that I bought as a parts car. The cobra wasn't running, but after the swap was complete the battery would be dead after a day or so just sitting in the garage. Car ran, no cel, nothing. I thought it was the gem and swapped out a few different ones and the problem was never corrected that way. I almost deleted the gem, but I got a wild hair and started parts swapping (starter, alt, fuses,) as I went back to check n double check all the connections. It ended up being the alternator. Hope this helps.
  3. Thanks
    Thanks for the reply. Did your gem module indicate a draw?

    The previous owner said he replaced the alternator with a repaired one. What on the alternator could possibly be causing the draw?

    I also read that the radio and gem share the same ground, so I think the problems are related. My dome light doesn't come on when I open any door, related to gem.
  4. Subscribing... My dome light does not function. Traced the circuitry to the GEM. Fuse #7 blows , immediately. I swapped out the GEM module with a used one. Fuse no longer blew, but car would not start. I did take the "new" GEM apart, and immediately saw that there are no user serviceable parts inside.

    One thing I did notice is that condensation from the A/C system vents and plenums does drip directly on the GEM on very humid/hot days.

    Not a whole lot of info in the FSM, either. So I hope somebody knowledgeable chimes in.