It’s my plow truck for 6 months of the year. I bought it lightly used (very) and put a plow on the front, and a winch on the back.
My question - would/could all that extra battery cable for the plow and the winch (again the winch is on the rear) put a slight drain on the battery even when the truck is not in use? Or should I be looking for a short.
The battery and starter are only 2 years old.
I start it weekly, to charge the battery. But tonight at -2f it barely started. I know I’m asking a lot from the battery to run the plow, but it seems to me that the battery is draining when not in use, and am wondering if it’s because of all the heavy gage cable that is hooked up to it for the plow and winch.
(yes, I’m thinking about getting a trickle charger. That’s a bit problematic though as the only place to put it is on the dash or windshield. Due to the amount of snow we get, it would never get any sun)
Beowulff has it mostly right. The cables themselves don’t matter. But if those cables to either the winch or the plow end in a “magic black box” that box can be a load even when the plow or winch aren’t in use. With battery-draining consequences.
You can install a simple mechanical cut-off switch upstream of them both and see if that cures your problem. e.g. Medium-Duty & Heavy-Duty Battery Switches although there are thousands flavors of these things.
From your overall problem description I’d sooner believe the problem is inadequate battery capacity. At -2F, as you know, the capacity of a conventional lead-acid battery is a small fraction (WAG 10%) of the rated capacity. Any age-related weakness is fatal.
Ensuring you have a good newish battery as job #1. $50 for a new high capacity battery is trivial compared to the expense of a detailed electrical system diagnosis and rehab. For probably equivalent results.
I cannot count the cars who’s electrical gremlins I have cured with a new battery and no further troubleshooting. Cheap insurance indeed.
Thanks. The truck does have an aftermarket stereo in it. Damn thing has 17 buttons on it’s face and even a remote control (seriously? In a two door truck?). I think I’ll start there.
Was just wondering if all that cable (there must be 40 feet of it) might be a problem.
Can I check across the battery terminals with a multimeter to see if there is a “phantom” load?
No, you need to connect the meter in series, and set it on “amps.”
Be careful - if you turn on your headlights or some other big accessory, you will blow the fuse in the meter!
Right. You need to pull one terminal off the battery (negative is probably best), then connect one meter probe to the removed terminal and the other to the battery.
I saw a great youtube video on tracking down phantom loads. The guy had his DMM in series with the battery and started, one by one, pulling fuses until the amps dropped off. But he first went and clammped the door switch shut since on so many cars, opening the door triggers a lot of things to happen. Dome light, head/running lights, in some cars the fuel pump spins up. The computer can come to life etc.
On many cars, you actually have to turn them off, find a way to hold the door switch down, then wait 15-30 minutes for everything to shut down before you can start testing…oh, and if the interior fusebox is on the passenger side, you have to start all over if you didn’t think about that.
Here’s the video, it’s very detailed, but actually pretty simple.
FTR, the first thing my dad would always tell you if you battery was always dead in the morning is to go and look at the car at night to see if any of the lights are staying on. Dome/map, glove compartment, under the hood, anything. If any of them are, remember when you go to take it out…it’ll be really hot.
Is that -2c or -2f? If it’s Fahrenheit, and most of time you’re going to be using the truck it is going to be that cold out. you might want to get your self a battery warmer, and block heater. Also the radio is aftermarket I would start looking there for gremlins… Who knows what they did or didn’t do correctly when installing it.
Yeah, when I had the plow and winch put on (I don’t do that stuff anymore) I had them put in the best battery available. I’m not even sure what it is. It may be crap.
It’s a bit rough to work on it in the winter. Life and weather gets in the way. I don’t have a garage. I did just order a portable jumper battery. That should get me through the winter if this happens again. Much easier than trying to maneuver my Pathfinder close to it (often in deep snow) to give it a jump in the dark. That just SUCKS.
The hi compression of the hemi probably doesn’t help.
Starting it weekly may cause more harm than good. Invest in a good charger capable of providing at least 10 amps. Solar chargers and tenders are good but don’t have the juice, they are designed to maintain a battery at 100%.
Cables and connections loom doubly important when running a plow. Remember practically any amount of resistance in the charging circuit will cripple the alternator, add on to that a power hungry plow, there’s no way the battery can keep up and will get smoked.
I should also look into a heavy duty alternator, if available for the truck. When I’m plowing, it’s usually at night with lights on bright, the heater fan and wipers going too. Hmmm…
Look up “voltage drop test”; this is really slick and doesn’t require disconnecting anything, just a voltmeter set on its lowest setting. Works for anything, starters, headlights etc. The principle is that measuring ohms resistance is useless for high current devices, so they are tested under load. Anything more than a few tenths of a volt is considered excessive.
I’d replace the starter cables and various ground cables before the alternator. Here’s why. Just .06 hundredths of an ohm (almost too low to measure accurately) with a DMM) will reduce alternator output by almost 30%. This is why the voltage drop test is used. I like 1/0 cables.
