Question help - what's on this circuit?

lee_greco · #1 (**permalink**) 07-02-2008, 08:02 AM

What's on the Tow circuit on an 05 SR5 V8 AC w/o tow package? My battery is dead after leaving the truck sit for 3 days . Traced the problem to a 1/2 amp draw on the circuit labeled TOW on the fuse panel under the hood. It's a 20 amp fuse. Any ideas on what could be causing the draw (other than a wire short or corrrosion at the connector)? Can I safely pull this fuse and leave the circuit dead? Thanks in advance.

UnSub · #2 (**permalink**) 07-02-2008, 05:40 PM

Quote:

Originally Posted by lee_greco

What's on the Tow circuit on an 05 SR5 V8 AC w/o tow package? My battery is dead after leaving the truck sit for 3 days . Traced the problem to a 1/2 amp draw on the circuit labeled TOW on the fuse panel under the hood. It's a 20 amp fuse. Any ideas on what could be causing the draw (other than a wire short or corrrosion at the connector)? Can I safely pull this fuse and leave the circuit dead? Thanks in advance.

I am looking in my book and I don't see a fuse for 20 amps labeled "tow". If you will double check to see what it says again and also list the name of the fuse on each side of it, I will look at the schematics tonight and try to help.

tempetom · #3 (**permalink**) 07-02-2008, 06:26 PM

Yeah, I checked also and there seem to be several fuses with tow in their titles. I'd pull the fuse and see what happens?

lee_greco · #4 (**permalink**) 07-07-2008, 08:10 AM

I'm really sorry but earlier I posted the wrong details. This is actually a 2003 Tundra and it's a 30 amp fuse labeled TOW TAIL. The fuse is in the foremost bank between several empty slots. It is perpendicular to and between the 5 amp ECU-B and the 15 amp PWR OUTLET 1 fuses.
When removing/replacing the fuse, the TOW TAIL relay throws. I've tried other relays in that location and they all give the same behavior. This truck does not have the tow hotch or package but does have the bumper that can take a ball.
Thanks again.

tempetom · #5 (**permalink**) 07-07-2008, 11:54 AM

My manual only shows the circuit going to the relay then to the trailer connector "tail" pin. Can you look under the back and see if the connector was removed and maybe the wire is shorting? It should be a brown and/or green wire.

shall36 · #6 (**permalink**) 07-07-2008, 12:05 PM

Try this:

lee_greco · #7 (**permalink**) 07-07-2008, 12:15 PM

Thanks much!

BAD BONEZ BJ · #8 (**permalink**) 07-07-2008, 12:27 PM

Ahhh! A 2003 Tundra. There is a TSB that covers that year model which has a wiring error. If you use the Auto-Off feature with your headlights, you are leaving the trailer circuit active. Manually turn your headlights off to kill this battery drain.

I have posted about this before, follow this link for the fix and a copy of the TSB.
http://www.tundrasolutions.com/forum...83/#post922383

BJ

shall36 · #9 (**permalink**) 07-07-2008, 12:37 PM

But the OP says he does NOT have the tow package. Interesting...could this still be the problem? Looking at the diagram, I don't see what else would be causing the draw.

Tundradrenalin · #10 (**permalink**) 07-07-2008, 02:53 PM

What about the TSB for the parasitic draw from the JBL amp? lee_greco, you have the JBL audio system?

BAD BONEZ BJ · #11 (**permalink**) 07-07-2008, 06:39 PM

Quote:

Originally Posted by shall36

But the OP says he does NOT have the tow package. Interesting...could this still be the problem? Looking at the diagram, I don't see what else would be causing the draw.

Yeah, I caught that too. But if he has the circuits and fuses for Towing, then he has the same problem I had with the Circuit being left on (only applies to the AUTO-Headlight Off Feature), manually turn your headlamps off and see if that circuit still has the draw. If not then the TSB doesn't apply to this situation.

TSB for the amp. More details please, I don't know anything about this one.
BJ

Tundradrenalin · #12 (**permalink**) 07-07-2008, 06:49 PM

Sorry, I just read the TSB, it's for the '04-'05 DCab Tundra. TSB-AU001-05.
Production VIN dates before: 5TBDT441#5S480009.

...also for ’04 – ’05 4Runner, Prius, RAV4, Sienna, Solara, ’05 Corolla, Matrix, Sequoia, Tacoma

Some customers may intermittently experience a pop noise while turning the ignition key ON or OFF due to the JBL amplifier staying ON when the ignition key is OFF. This could result in a dead battery after an extended cold soak. An updated JBL amplifier is available to address this situation.

BAD BONEZ BJ · #13 (**permalink**) 07-07-2008, 08:54 PM

Thanks for that clarification, and for covering who it does apply to.

I think all the '03s have this problem, and it's only when and if you went to the dealer that they might tell you about it. In the meantime, you drain your battery every time you use the Auto-Off Headlight feature and leave the lights on. It leaves that trailer circuit on, as if the headlights were still on. But, I'm not sure there should be any draw if there is nothing connected to the circuit or, not enough to drain the battery

I noticed this the first time I hooked up the trailer and had the headlights on when I turned the truck off and jumped out. Lights went out everywhere but the trailer. It was if I still had all the lights on.

Do a search on the forum for that TSB and you'll find lots of discussion on this problem. I have the harness, but have never taken the time to install it. I just manually turn my lights off - old fashioned.
BJ

lee_greco · #14 (**permalink**) 07-08-2008, 06:44 AM

Thanks to all of you on the forum. Turning off the lights cut the current draw dramatically, from over 1 1/2 amps to around 0.3, but the residual still looks like it's more than just the clock and keyless entry. I've got an aftermarket sound system and alarm in it so I may just have to deal with that draw. I'll do some more fuse pulling this weekend. Hopefully I'll be able to start it without a jump after coming back from vacation