Dead batteries in 24hrs - amperage draw???

[mn_warden]

Does anyone know how many amps I should be drawing with everything off? I am drawing around 3 amps????

I have been having dead battery issues for about 5 days now. I replaced the batteries about 2 years ago and installed a battery tender that I use just about every night. It is a 2002 Excursion with 7.3 which sits in a temp controlled garage.

Thanks in advance....

[Zaairman]

3 amps is crazy high. I'm not sure what our trucks draw, but most vehicles are around .3. I just tested my brother's Ranger the other day, it draws .25.

[NoRalPh]

This used to be an easy question, Today it is Not....

There are so many managed systems, that take up to a 1/2hr to go to "sleep", it's hard to say exactly what you should see in your trucks configuration. BUT without any lights on (like interior) 3 Amps is too high I'd think.

I'd start by pulling some fuses out as it sat and see what happens. The most likely culprits for Hi Draw problems are radio, alt, dash cluster. Try taking those fuses out and disconnect the alt to start. If it fixes it, reconnect them one-at-a-time to find the problem.

If not, try other circuits, but remember, there actually IS supposed to be a constant draw (eventually under 300mA) at all times to support the computers. You have 2 Large batteries that can take that without a problem. In fact, I'd think good batteries would be able to take even a 3A draw overnight... Maybe, even though they're only 2yrs old, you might want to have them Load Tested (at a High Rate) to be sure they're OK...

[coot1]

When you checked your current draw did you diconnect both batteries. You could have a bad battery and the current draw you are measuring is the current going from the good battery to the bad battery. I would disconnect both bateries and then hook my ammeter up in series with one of the batteries to the disconnected cable to measure the current draw. If the current draw you measure is low in the milliamp range then hook up the other battery while monitoring your ammeter to see if you get a big increase.

[Cwoods]

Probably no relation to your problem but I just had to buy 2 new batteries..... killed those to, 20 min from full charge to dead with the key out. Reached up 5 seconds after hooking batteries up and the glo plug relay burned the hell outta me..... 45 dollar and back in business and luckily glo plugs are still testing good. Just a thought

[RockinT]

Originally Posted by Cwoods

the glo plug relay burned the hell outta me..... 45 dollar and back in business and luckily glo plugs are still testing good. Just a thought

Are you saying the glow plug relay was killing your batteries?

[Cwoods]

Absolutely was. It was so hot it started melting adhesive out of the connectors on the GPR and did in the boot over the hot post on it as well. I broke the old one apart and the disc that makes contact with the posts when actuated was fused right to the posts.
2 years ago I replaced it because it wouldn't make contact and heat my glo plugs so wasn't expecting the opposite. I replaced the GPR and problem solved.....after buying two new batteries and an alternater suspecting bad diodes in it. It was pulling all the power out of the batts in 20 minutes and no arcing whatsoever ever on the batt posts when hooking the cables back up.
did some research and have a Stanford(believe that's the name) relay coming my way that's supposed to cure failure probe and will use this one I just installed as a backup stored behind the rear seat.

[RockinT]

Good to know. I'm fixin to order the glow plug, harness, gasket kit that comes with a new GPR. I've lived with a slow cranking truck long enough. New batteries were a fast crank for the first few weeks, but it's dragging again. I'd say it's time for these never been replaced parts to get replaced. It will be nice if it cures my battery drain problem too.

[mn_warden]

Thank you to all who replied with suggeswtions. I will follow up with and attempt the recommendations and hopefully find the problem with my limited mechanical capabilities. It might just end up at the shop for the trained and experienced professional.

[xscoobysnack]

I have a similar problem with batteries that are dead in 24 hours. The parasitic drain on the system with everything off is only 0.38A which should be acceptable. The GPR tests fine and if it wasn't, the draw would be much larger. The batteries are almost new. I am leaning toward a faulty alternator but didn't want to just throw parts at the truck. Anyone have any thoughts before I change out the alternator? Thanks.