Prodigy Brake Controller/Dead Battery in TV

[OB Bambi]

I have a 2001 Expedition with the factory installed towing package. When I bought my Airstream 2-1/2 years ago, the A/S dealer (who I since have come to realize wasn't too sharp), installed a Tekonsha Prodigy Brake controller. It works fine. What is happening since is, if I don't drive the Expedition for a couple of weeks the battery goes dead. I think that the Prodigy is draining the battery. I had a 18 month old Costco battery, it went dead a couple of times and I thought it had a bad cell. I took it back to Costco and they exchanged it for a new one. (The top of their line). That one is less than one year old and it is having the same problem.

Does anybody have an idea as to what is going on? Should I unplug the Prodigy controller? (Take it out of it's cradle when not using the A/S?).

...and don't say...simple, just drive the Expedition more.

Thanks, Randy

[Relentless]

Yes. Unplug the Prodigy if you are not going to use the Expedition for a week or more to tow. I have an 2006 Expedition and a Prodigy and the Prodigy will run the battery down after a few days.

John

[ROBERTSUNRUS]

Hi, since the brake controller is basically just plugged into the factory harness, it would be very difficult to wire incorrectly. [but not impossible] Your vehicle has several other items, with memories, that have a draw on your battery so if you don't want a dead battery, then you should look into a small solar panel that sits on your dash or sticks to your windshield. Also you can use a small trickle charger. I would not recommend disconnecting your battery because some items in your vehicle will lose their memory and/or will have to re-learn their functions.

There I didn't say it.

[HowieE]

I doubt that it is the brake controller that is draining your battery. The only time the controller draws current is when it is applying the brakes and then that current is measured in amps and would kill a battery over night if left on.

Yes you can disconnect the controller for a couple of weeks but it sounds like you not using the TV enough to recharge the battery. How often and how far do you drive the TV without the trailer? It takes at least 20 miles of driving to recharge a battery after one start. If you are only doing around town short runs you are draining the battery.

Another think to look at is the alternator. If you have a volt meter measure the battery voltage while the TV is not running. Now start the TV and measure the voltage. If the voltage does not increase by several volts from the first measurement you have an alternator problem. A good alternator should put out about 14 volts just after a start up.

[Phoenix]

I had a Prodigy in our old Chevy pickup, which sat for 30-60 days between uses (we used it only for towing our Airstream). We never had any problems with the battery going dead, so I doubt if the brake controller is the problem. I'd check for something staying on when the ignition is off (like a light in the glove box, visor mirror, etc.; i.e. a parasitic drain).

[Ganaraska]

Here is a way to find out what is draining your battery. Disconnect the ground cable from the battery. Connect a 12 volt test light between the battery post and ground. If there is a current drain the bulb will light up. Now disconnect the brake control and see what happens. If the light is still on take out the fuses one by one. When the light goes out that is the circuit that is causing the drain.

Turn off the courtesy lights when you do this. You usually have the car door open while doing this test. With the door open the lights will come on. This will give a false impression that the courtesy lights are the problem. Check that circuit with the door closed and the courtesy lights on.

[HowieE]

There are several things in the newer cars and trucks that will draw current while in storage mode. The radio, alarm system, and any other computer or chip device that has memory.

A test light will remain on as long as these devices are in the vehicle.

You can get an idea of how much current is being drawn if you bridge the gap between the battery ground and the battery cable with a 2 amp fuse. If the fuse blows you do have a current drain that will kill the battery in short order. The memory chips won't draw 1 amp.

[BeBop]

Originally Posted by Phoenix

I had a Prodigy in our old Chevy pickup, which sat for 30-60 days between uses (we used it only for towing our Airstream). We never had any problems with the battery going dead, so I doubt if the brake controller is the problem. I'd check for something staying on when the ignition is off (like a light in the glove box, visor mirror, etc.; i.e. a parasitic drain).

My experience is similar to Phoenix, except I drive my rig only to tow the Safari or the sailboat (and/or pick up some large items)... usually about once a month for a short distance. The Prodigy is always in the circuit with no drain or loss on the battery. You are experiencing a parasitic circuit somewhere. I know what a disappointment a dead battery can be... happens at the worst of times. Ganaraska has an excellent technique for analyzing the problem.