Just bought a new 2008 RTX, brought it home, let it sit in garage for 7 days while I was away and came home to a dead battery. Recharged battery and took it to local service department. Battery checks OK. Had tech put amp meter in line with battery and reading is 350ma with everything off. If we pull the 40A (#15)fuse in the engine compartment the ma load goes to zero. Service department sent me home with a promise to call when they get some technical advice. Has anyone ever seen this before?
John B
There's been at least one other on the forum that had this problem. I don't think it's common. Is the truck completely stock, or did you add anything to it?
350ma would be enough to kill a battery over 7 days. Especially if that battery wasn't fully charged to begin with - as most new car deliveries sit on the lot for a while.
That amount of draw sounds like a small light is left on somewhere.... something like the light inside the trunk or a dome light. The :normal" amount of parasitic draw should be around .025a and is often times closer to .018a. There is certainly a draw on one of the circuits protected by the fuse - there are more than a few circuits per fuse..... so the shop will have to do some futher diagnosis to find the source.
HT
That amount of draw sounds like a small light is left on somewhere.... something like the light inside the trunk or a dome light. The :normal" amount of parasitic draw should be around .025a and is often times closer to .018a. There is certainly a draw on one of the circuits protected by the fuse - there are more than a few circuits per fuse..... so the shop will have to do some futher diagnosis to find the source.
HT
either way, I have devices hard wired in that total well over 350 mA and I have no issues whatsoever. I'd change out the battery...
I cant give you an actual number. I can tell you that the headlights draw more than ten amps. I was measuring parasitic load once and turned the headlights on. The 10A fuse in my multimeter comenced to fail immediatly.
So over 10A.
HT
So over 10A.
HT
Here is an amp hour calculator that I like to use.
Lifeline Batteries - Marine & RV Deep Cycle Batteries
The headlights are 55 watts each hence 110 watts total which would be less than 10 amps combined. I would think that the reason why HondaTech blew the 10 amp fuse in his multimeter was because of a bad/insufficient ground and the circuit tried to pass power thru the multimeter.
My guess would be that they are pulling one of the main fuses and hence killing the power to the entire truck which is killing the load. Please tell us which fuse they are pulling.
My guess as to what is killing the battery which is probably no good anyways is the trailer wiring harness. It is the X factor since he has an RTX. It could also be a faulty or loose connector anywhere under the hood but my money is on the trailer wiring harness.
If this truck has had this problem since it came from the factory the battery must have been charged a few times and have been jumpstarted a couple of times as well. I would bet that the battery has a dead cell. Take the truck to autozone or a place of the sort and have them run a load test on it. I bet it fails.
Let us know what the problem ends up being. One thing though. If it is a bad ground they might have your truck for a while. Bad grounds are hard to find.
Lifeline Batteries - Marine & RV Deep Cycle Batteries
The headlights are 55 watts each hence 110 watts total which would be less than 10 amps combined. I would think that the reason why HondaTech blew the 10 amp fuse in his multimeter was because of a bad/insufficient ground and the circuit tried to pass power thru the multimeter.
My guess would be that they are pulling one of the main fuses and hence killing the power to the entire truck which is killing the load. Please tell us which fuse they are pulling.
My guess as to what is killing the battery which is probably no good anyways is the trailer wiring harness. It is the X factor since he has an RTX. It could also be a faulty or loose connector anywhere under the hood but my money is on the trailer wiring harness.
If this truck has had this problem since it came from the factory the battery must have been charged a few times and have been jumpstarted a couple of times as well. I would bet that the battery has a dead cell. Take the truck to autozone or a place of the sort and have them run a load test on it. I bet it fails.
Let us know what the problem ends up being. One thing though. If it is a bad ground they might have your truck for a while. Bad grounds are hard to find.
I have a printout of fuse/relay boxes from the service manual. The fuse you pulled was actually #7 labeled BU. Fuse #6 is a 10 amp labeled Intr Light. If it's any help here's what fuse #7 protects on your RTX:
Combination Switch Contrul Unit
Gauge Control Module
Ignition Key Switch/Key Light
Immobilizer Control Unit-Receiver
MICU
Power Window Master Switch
Wiper/Washer Switch
Combination Switch Contrul Unit
Gauge Control Module
Ignition Key Switch/Key Light
Immobilizer Control Unit-Receiver
MICU
Power Window Master Switch
Wiper/Washer Switch
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