Can Tire Pressure Detectors Drain Van Battery?

joey2cool · 10-22-2015, 06:23 PM

Does anyone know if Ford's tire pressure detectors constantly transmit a low pressure RF signal when the engine is off? Enough to drain the van battery in just under two weeks?

I found my van battery completely drained less than two weeks after a multi-hour drive. No voltage reading, not even enough juice to power the voltmeter. Couldn't even open the doors with the remote key.

The battery is OEM Ford Motorcraft. Five years old. No previous problems. Routinely charged and giving good voltage readings. Cold crank test done every year - also good. No blown fuses. No indication of other trouble with the van.

I was able to jump start the van with SMB's house battery cross-over switch. The low tire pressure dashboard indicator light is on - presumably because the settings were lost due to the power outage (radio settings were lost too). Just to be safe, I had the tires serviced immediately and the two back ones came up 5 psi each below door label pressure specs.

I have not had any problems since recharging the dead battery. Don't know what to make of it.

**daveb** · 10-22-2015, 06:46 PM

I don't know about the tire pressure system but I get your point. So was your tire actually low? Seems like if you've had it all these years and only now you've got an issue, I'd be wondering if you have a different thing going on. I'm sure you checked the radio switch to make sure that didn't get left on. I'll also say that 5 years is pretty good life for your starting battery. You can charge it up and see if the battery fails. Also if you drive a distance and the battery gets hot to the touch, that is a good indicator the battery is on its way out.

Btw I didn't get a door fully closed once and the dome light pulled the battery down. The couple days after I'd parked the car I was wondering why I had a dead battery. Charged it up and no problems. Then a few days later my neighbor asked if somebody had broken into my car. I asked why he thought that and he told me my interior light way on in the middle of the night a few days back

BajaSportsmobile · 10-22-2015, 08:51 PM

No. The sensors have their own small battery and the receiver is off when the ignition is off.

JWA · 10-23-2015, 04:19 AM

I would have the battery "professionally" re-charged, load tested with a carbon pile type tester first. Next up would be a full diagnosis of the alternator output, testing it off the vehicle if someone in your area can/will do that. After all that was known to be in good operating order I'd do a parasitic amp draw test to see if anything is drawing down the vehicle electrical system.

Honestly at 5 years old for an OEM battery is a good life---my own experience with most good to better starter batteries is anything past that point is all good grace.

Steve_382 · 10-24-2015, 06:43 PM

X2 on 5 years for a starter battery. I change mine on all my vehicles at 4 years. It's worth it to me not to have to deal with a dead battery sometime when I don't really want to deal with it. If it's a $200 battery, that extra year is only $50. If I was sure it would happen while I was near home or civilization, and on a nice sunny day, who cares, but if I am out traveling, or it's snowing and below zero, it doesn't really seem like much of a savings.

JWA · 10-25-2015, 04:59 AM

I'll add just one more thought about starter batteries, at least as far as gas motors go..........

NAPA's top brand have been absolutely flawless for me the past 10-12 years----the latest versions being claimed to be the best ever. Their liberal full replacement warranty is great, 18 months then prorated out to 7 years after that.

Yes they top $100 each, cheaper are available everywhere but with my experience living/driving in Ohio and have NEVER had one last any less than 5-6 years that cost is insignificant. Apart from occasionally testing them with a solid-state load tester and spot checking the charging system I do nothing maintenance-wise and they don't seem to mind.

Periodic cleaning the cable ends they're pretty much automotive hermits----and happy to be so.