batteries draining?

[lmholmes11]

Ever since I put a Tekonsha P3 brake controller in my truck, it seems like it has been taking longer for the truck to start (a little bit longer crank time). Last night I was doing my power steering flush and the truck just clicked like it was low batteries. Voltage at batteries is 12.66 volts. Is it possible my brake controller is slowly draining down my batteries? I believe they are still the originals. Maybe time for new batteries.

[greatwhite]

If I remember the p3 manual correctly, it should shut down complty after 5 mins and have no draw.

Now, notice I said [i]supposed[\i] to....

I have a 60 amp cole hersee relay under the hood that activates with acc power. When I shut the truck off, my p3 goes off. No questions asked.

Charge your batteries back up to snuff over night and see what it is in the morning. If it does again that day, take it to a shop and have them load tested.

If your batteries are over a year or two old, it may just be thier time.

The other possible issue is the alternator is not up to new specs stuff.

Lastly, if you do a lot of short hops around town, your batteries will eventually loose charge. Our high compression engines suck a lot of juice at start and a short hop trip doesn't bring them back up. Do that enough times and they will evtually reach a point where they just don't have enough "poop".

[lmholmes11]

I charged the batts up over night, multimeter said they were at 13.66
volts. Went on a 5 hour long drive with the boat no issues. Got back last night and rolled both the DS and PS windows up St the same time and all my lights dimmed when I hit the switch, truck was running. I'm thinking a charging issue. Going to test alternator output next.

[DmaxMaverick]

Check voltage while running, then while off. If they are the same, or close, it's the charge system. If you have 14.5+ on, and 13.x off, it's probably battery(ies). Disconnect one ground and test again. Switch grounds, and test the other. You may have one battery going south, which is usually the case. Leave the batteries separated overnight, and test independently before and after a start in the morning. The truck should start cold with only one battery, this time of year. Try starting with only one battery. Shut off, then try with the other. One bad battery will discharge (and kill) a good one.

I don't think even good batteries would survive 5 hours running w/o the alternator, especially if headlamps and blower were used. Sounds more like batteries, if it was fine on the trip. If it weren't charging, the battery indicator should be illuminated, as well.