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Parasitic Draw Questions

450 Views 8 Replies 3 Participants Last post by  Moose 04.5
So I've had a parastic draw on the truck for about 1.5 years now. My truck never sat long so it was never really a big deal until now. I'm not sure if it's worse or it's just because it's sitting longer now. I have a 1.3-1.5 amp draw. When I disconnect fuse 51 it goes away to below 50 miliamps which is what is supposed to be at from what I've read. I've narrowed it down, I THINK, to the cluster. The reason being I take the three plugs out for the cluster and the amp draw drops from that 1.3-1.5 amps to the less than 50 miliamps. I plugged it back in, amp draw went back up. Unplugged radio, didn't change. Yeats ago I sent the cluster to circuit board medics, several times it had a couple issues with it not being calibrated right, and I put in led bulbs in it. Some of them never really worked or would work if you hit a bump and shook them. But with the fuse 51 pulled the cluster and overhead still work including the backlighting on the cluster (I think), but the radio would not work at all and neither would my Smarty touch in my OBD2 port. So, is it actually the cluster or could it be somewhere else? I'm having issues with the remote not working either, but that could be an issue with door wiring or the aftermarket remote start I'm not sure. The E brake light is also staying on and the brake lights are all staying on all the time too including the 3rd brake light. Which I've read could be the master cylinder or the reservoir switch, tried 3 nothing changed. Did the 4th gen hydroboost with 4th gen master, didn't have issue before it so I think it just may be a bad resivour??
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Amp and an half seems like a LOT to me for something like the cluster, with no "visible" symptoms. WATTS= IE (current in A x V) that's nearly 20 watts!! That's enough to warm things up!!!

EG just for fun I looked up a 1004 dome lamp, they get hot as hell and are less than that.
Yea it is quite a lot that's why I'm surprised removing the cluster did drop it so much.
Your brake lights outside stuck are on? That is actuated by a grey switch mounted near brake pedal. Those are picky and you have to adjust them correctly. So it’s either that or the switch is not even mounted. It could be hanging there.

As for power draw, unplug smarty and radio and see if it stops. Those smarty touches draw a bit while parked.

Also I recommend unplug/remove aftermarket remote start for testing. That may be the problem too.
Will do thank you! Will be checking on this today, but only thing that worked yesterday was unplugging cluster, but I will check the radio and smarty. I'll have to check the brake light switches, only reason I thought it was the master cylinder fluid level sensor was because the ebrake light is stuck on as well.
Things I'd keep in the back of my mind:

ANYTHING aftermarket added especially entertainment, amplifier etc
Lights, glove box is small for that draw, but any lighting, camper?
third brake light?
Keep alternator in the back of your head. See if it is warm.
Check the lighter and accessory outlet

You are probably aware that some things automatically shut down after a delay so don't let that lead you down the wrong track
I'll keep that in mind. Recently yes have added quite a bit, however this happened before the amps and bumper mounted lights. I'll keep checking all of that. Kind of a stupid question, but I'm assuming leave that fuse 51, the one creating the parasitic draw, plugged in and test for voltage on various pieces of equipment or accessories and use that to determine where power is going correct?
Ok brake problem solved, was the brake switch. Threw me off because it was never touched or messed with but the master cylinder was, and a bunch of old threads I found a lot said it could be the issue. So thankfully thats fixed. Haven't had a chance to find where that parasitic draw is coming from just yet, had to get truck ready to go down to Tennessee for my wedding. When I get back I'll do some more testing with it.
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