Hello to everyone. I just joined this forum and I am in need of some help. I have a 05 f150 with the 5.4 3 valve that I have just rebuilt. I am now having a problem with a drain on the battery. What is happening is with the key off and the positive side corrected to the battery. I can put my test light between the battery neg. post and the negative cable and the light come on. The only way it goes off is if I disconnect the cable going that powers the fuse box. I have pulled all the relays out and the light still stays on. Has anybody had this problem or could tell what I need to do now. The only think I can think of is start pulling fuses one at a time and see if the light goes out. Sorry for the long post just wanting to give all the info that I have as of now. Thanks for any help.

 

Pulling fuses 1 at a time is probably your best bet. Then when you find it, check all the associated pieces of equipment. Did this just happen after the engine rebuild, you did have the engine out of the truck right?

 

Yes I did a complete rebuild with new everything including sensors. Yes this as happened just since the rebuild.

 

If my memory is correct on most 05 trucks there is always a small draw on the battery even when the key is off in order to power the security system blinking light and one on the sound system in addition to other sensors, etc.

 

would it cause a test light to light up bright

 

I don't know the answer to that but you could use a VOM to see how many amps it was using. If it is just the sensors and security system it should be very small. Otherwise the previous suggestion of pulling fuses and relays is the thing to do.

 

Can you hear the fuel pump running? My dad had an 06 with the 5.4 that the fuel pump would occasionally stay running after the truck was turned off.

 

Can anybody tell me where the g e m module is located in a 2005 lariat

 

do not think 04-08 has a GEM

 

Also don't think so