T300 Current Draw

I've got a T300 that loses its batter charge after about a week of no use.

I've put a meter on the various fuses and other than my GPS tracker at 80mA the only other draw is the Brake Switch / Flasher circuit at 600mA.

You can also hear an audible click under the cab when that fuse is removed.

T300 with C7 and Allison 2200.

Where should I look next? Is it reasonable for the brake switch to pull 600mA when truck is off?

 

Hello Northern,

Yes I am removing the fuse and the completing the circuit with my meter in current mode.

Most of the locations measure zero through where the fuse would be, but the Brake SW / Flasher circuit measures ~600mA. Likewise when that circuit is completed by either a fuse or the meter you can hear some sort of click under the cab or near the the shifter.

No other items are connected directly to the battery except the box overhead lights, which are switched off.

I am pretty convinced that the 600mA draw is my culprit, as that is about the range that would cause my battery to die in 7 -14 days depending on state of charge. I do have a solar tender that works well in my other vehicle which can provide 5W / ~150mA, which has done well for us in mitigating the small load from the GPS tracker, but this 600mA is too much for it to keep up.

Thabks

 

Yea I'm just not certain what is connected to that circuit with out a service manual or block diagram. I did remove the flasher relay / control which rendered the flashers useless of course, but the 600mA draw was still there.

It is something to do with that "brake sw", but I don't know what or where that is. Maybe I will try to listen more closely where the noise is coming from. Certainly sounds like shifter or directly under the cab. It is quite loud and plasticy sounding.

 

Here is where the current draw is coming from, this device in the shifter (Morse Controls). It is what is making the noise and is also hot to the touch even when the truck has been off overnight.


http://imgur.com/gallery/afI69fL

I am unable to find any additional fuses or relays other than the ones inside the cabin.

Where are the engine fuses located on a T300 w/ C7?