Stand-By Current Draw/PCM Current Draw?

[MikeVistaBlue06]

I am wondering how much current our PCM draws when the car is OFF.

I've had my battery die 3 times if I left the car sitting for 2 weeks. Yeah, I know I should drive it more.....

However, I made sure that the radio was off before I got out of the car because I have the Skipper 1000 and it was known to cause the battery to die if you didn't shut it off before getting out of the car.

I bought a battery tender that is 1.5A slow charge with a "float" charge to keep the battery hot. This small charger indicated it was in charge mode since I installed it and plugged it up. It even indicated charge after I drove it around quite a bit today. I was surprised it didn't just top off the battery and go into "charged" state.

I have the battery tender as well as a regular battery charger hooked up right now and the regular battery charger is still showing a pull of 3A after being on there for 3 hours! I have driven the car quite a bit lately and was surprised to see it still pulling 3A.

I pulled all the fuses for the Skipper radio & amps to see what happened and I did not see the output drop from the battery charger one bit.

All the doors are shut, the trunk is shut and there are no lights on that I can see. So now I am wondering what in the hell is pulling a couple of amps in stand-by mode!

If there is something pulling that much current, no damn wonder the battery dies over a short period of time!

Any ideas?

I am thinking about pulling fuses until I see it drop, but I am waiting until the temp drops into the high 90s before going out there. August has arrived in TX!!!

Thx,

Mike

 

[cekim]

I am wondering how much current our PCM draws when the car is OFF.

I've had my battery die 3 times if I left the car sitting for 2 weeks. Yeah, I know I should drive it more.....

Don't know the idle current draw, but start with the alarm in your fuse pulling exercise...

With the stock battery - I was 100% sure to kill the battery in 2 weeks of idle time... No if's and's or but's - dead as a door nail - the only debate was how many HOURS it would take to charge it to the point that it would even crank...

no skipper/sub on that car - other car is newer so it took longer (3 weeks). Got a yellowtop for both and have had no issues so I stopped looking for the cuase. Radio off seemed to help, but the alarm was next - obvisouly no skipper/sub in that car, so no fuse to pull there...

 

[98yellowgt]

I had this same problem until I noticed the negative battery cable was loose.
I have let it set for 3 weeks and no dead battery.

 

[MikeVistaBlue06]

Update:

Well, the small charger finally indicated "charged" about 2 hours later.

I unhooked it and took it for a drive. It is hot here, even at night, so I had the A/C running and headlights on of course. My Passport 8500 said the car's voltage was between 13.7 and 14V so I know the alternator is working ok.

What is weird, when I got back into the garage and hooked up the small battery tender again, it is in "charge" mode.

Thanks for the tip on the alarm and its fuse. I hadn't thought about that.

Mike

 

[onehotpny]

Mine does the same thing as your's .I have no idea what is pulling it down,but this happens alot. I guess this is just one of these problems we'll have to live with.

 

[shard phoenix]

Mine has been on a battery tender for over a year now, with only one month of actual driving and the occasional start-up its fine. I guess the $30 tender was a drop in the bucket compared to what a battery would cost me!

Try it and call it an investment, they are available everywhere in various prices.

 

[G.T]

i have hard wired a Garmin GPS, Radar detector, Autometer gauges, Amplifier, Subwoofer and capacitor..
not trying to jinx myself but i left my car idle for 20 days while away on a trip.. got back expecting to give AAA a call, but she fired right up!

not sure what's drawing current in there, i know for a fact i can leave all my accessories on, and the car will automatically power everything off 10 minutes after i leave (radar/gps, etc)

 

[MikeVistaBlue06]

Update 2:

Looks like it charged up full overnight with the 1.5A battery tender. I guess at idle with the lights on, the A/C running on fan position 2 or 3, and the radiator fan running, that it took some charge out of the battery while I was parking in the garage.

This morning opened the door and watched the unit go from charged (green LED) to charge (yellow LED). I shut the door and when lights automatically shut off, the tender stayed in charge mode for about 2 minutes then switched back to charged.

If anyone is interested I got a Schumacher battery tender (model 1562A) at WalMart for about $19. It came with a hard wiring harness with a quick disconnect. I put the hot side of it on the tap right at the hot side of the underhood fuse box, and then connected the ground to the chassis right about the shock tower where my Saleen intercooler reservoir is located.

I am going to keep it plugged in while the car is parked and see if this stops the battery from draining!

Mike

 

[Tommyboy45]

Same problem here. Tried all of the ideas and testing with no luck.

It gets worse in the winter when stress is put on the battery by the temperature.

Invested in a Battery Tender Jr. I know I should not have to do this, but no headaches now.

 

[cekim]

Invested in a Battery Tender Jr. I know I should not have to do this, but no headaches now.

Look on the bright side - you can call it a "hybrid electric car"

 

[travelers]

i have hard wired a Garmin GPS, Radar detector, Autometer gauges, Amplifier, Subwoofer and capacitor..
not trying to jinx myself but i left my car idle for 20 days while away on a trip.. got back expecting to give AAA a call, but she fired right up!

not sure what's drawing current in there, i know for a fact i can leave all my accessories on, and the car will automatically power everything off 10 minutes after i leave (radar/gps, etc)

I would like to see what AAA would charge for a road call to UAE.

I have 3 batt. tenders on my H-Ds 2 ea never had a problem starting them and on the corvette.

 

[ixtlan]

Ever load tested the batt?
Could be shorted.
Harbor Freight sells a tester for about 20 dollars thats pretty good.
Get the larger one though.

93784-1VGA
Chicago Electric Power Tools 50 AMP BATTERY AND CHARGING SYSTEM TESTER

 

[G.T]

I would like to see what AAA would charge for a road call to UAE.

lol actually it's free of charge..
i have an annual AAA roadside assistance membership.. in Dubai

 

[biznazion]

I've had similar problems with my car since I bought it. It usually sits for a week at a time or so (weekend car). I've been hooking it up to a trickle charger at least once a week. Parking it with the radio and alarm off. Nothing seemed to make any difference. I was just away for a week - and trickled it full before leaving. It was deader than dead when I got home. Resting voltage of 5V - took it to Ford and they tested it - said it was toast. They gave me a new battery and I'm trickling this one full every week also, but I'll be surprised if this one doesn't do the same as the last one.

 

[don_w]

biznazion... welcome to S197Forum!!

 

[biznazion]

thx Don... I don't have much to add in the FI arena, but I can talk about battery problems all day long

 

[mck3125]

I've been having the same issue. Altough I have not had time to conduct a drain test, I found this Ford tech doc that steps you through the process.

 

[ZmanM3]

biznazion... welcome to S197Forum!!

+1!!!!!

 

[ZmanM3]

I have this issue as well and after draining the stock battiery and recharging it a few times it was shot and I now have a optma yellow top. I also disconnect the battery when storing the car for long periods of time.

 

[MrClean]

biznazion... welcome to S197Forum!!

+2!