| Non-GMC Battery drain. [message #72679] |
Wed, 03 February 2010 02:50  |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
OK, I'm chasing a battery discharge problem on my Colorado. If I park it for 2 weeks the battery goes dead. A new battery does the same thing.
I threw an ammeter on it and find there is a continuous 50 mil drawn. I do not think the is much too worry about.
Then I opened the door with the interior light turned off and the draw jumped to 250 mils (1/4 amp). That draw stayed there even after I closed the door. I think I woke up the BCM (body computer). A few minutes later the draw was back to 50 mils.
After that I touched nothing and checked it about 10 minutes later. The draw was back to 250 mils again. I think something is waking up the BCM periodically.
Anyone out there know what one of these things should draw when turned off and nothing going on?
Also has anyone ever seen anything like a recording ammeter or recording milli-ampmeter?
What also confuses me is I left a 13.2 volt 500 mil battery tender on the Colorado while I was gone to Quartzsite. When I returned 2 weeks later the battery was dead again.
I can park my GMC all winter and not run the starting battery down. I park this Collie for 2 weeks and the battery goes dead.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
|
|
| Re: Non-GMC Battery drain. [message #72681 is a reply to message #72679] |
Wed, 03 February 2010 06:00  |
lawrence gaskins
Messages: 8
Registered: January 2004
Karma: 0
|
Junior Member |
|
|
Hi Ken
You might try removing one fuse at a time and observe voltage readings.
This would find which circuit is draining the battery.
Lawrence Gaskins
West Union,Wv
www.Picturetrail.com/GmcLawrence
|
|
|
|
|
|
|
|
|
|
|
|
| Re: Non-GMC Battery drain. [message #72708 is a reply to message #72679] |
Wed, 03 February 2010 11:12 |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
|
Senior Member |
|
|
| Ken Burton wrote on Wed, 03 February 2010 00:50 |
OK, I'm chasing a battery discharge problem on my Colorado.
Also has anyone ever seen anything like a recording ammeter or recording milli-ampmeter?
|
Ken: I have a Fluke meter which has a recording ammeter/milliampmeter function which will give average current draw over time. I think this is what you are referring to in your request.
Unfortunately it is a Fluke, but it was made especially for Sears and is only listed as a Fluke 81438 True RMS multimeter. That is not a normal Fluke number. I am sure the regular Fluke series has the same feature, but you will have to look carefully at the specs to identify the specific model which has that function. I don't think that Fluke is making any special ones for Sears anymore.
Rob Allen
former owner of '76 x-PB
|
|
|
|
| Re: Non-GMC Battery drain. [message #72710 is a reply to message #72679] |
Wed, 03 February 2010 11:19 |
 |
RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma: 3
|
Senior Member |
|
|
I have a Motorola Two-Way radio dealership and we see this problem of phantom power all the time. The radio engineers have decided that the power switch should be a soft switch controlled by the microprocessor so the micro is always powered up. One popular model I can think of still draws about 100ma when turned OFF. This is enough to kill a good battery in a couple of days, or less in the winter.
There are Power Down Timers available, but they have shortcomings so we designed and built our own. Basically it leaves the equipment powered up for a set length of time after the engine is shut off, or until the battery voltage drops below a set level. When it times out, it cuts the power to the equipment completely and goes to sleep itself. The timer's average current draw when OFF is well under one ma.
When the engine is started and the vehicle voltage is stable, it powers the equipment back up again.
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
|
|
|
|
| Re: Non-GMC Battery drain. [message #72712 is a reply to message #72708] |
Wed, 03 February 2010 11:32 |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
|
Senior Member |
|
|
| idrob wrote on Wed, 03 February 2010 09:12 |
| Ken Burton wrote on Wed, 03 February 2010 00:50 |
OK, I'm chasing a battery discharge problem on my Colorado.
Also has anyone ever seen anything like a recording ammeter or recording milli-ampmeter?
|
Ken: I have a Fluke meter which has a recording ammeter/milliampmeter function which will give average current draw over time. I think this is what you are referring to in your request.
Unfortunately it is a Fluke, but it was made especially for Sears and is only listed as a Fluke 81438 True RMS multimeter. That is not a normal Fluke number. I am sure the regular Fluke series has the same feature, but you will have to look carefully at the specs to identify the specific model which has that function. I don't think that Fluke is making any special ones for Sears anymore.
|
Ken: I just looked at the Fluke site, and it appears that the current Fluke 27II has the feature:
"Average responding voltage and current for measurements (27 II)"
Rob Allen
former owner of '76 x-PB
|
|
|
|
| Re: Non-GMC Battery drain. [message #72715 is a reply to message #72679] |
Wed, 03 February 2010 12:29 |
 |
gmcdude76
Messages: 102
Registered: December 2009
Location: Northern Ca
Karma: 1
|
Senior Member |
|
|
Gmcers,
I have a simaler deal with the gmc 76 Birchaven.i was told
when i bought it i had a power drain on my system.the red light on the dash stays on all the time.i had just enough drain to drop my batterys(trojan misor 125)low enough they wouldent kick over the generator.theyd only last a couple of days.now i think i ment there over 8 years old and dry cells.i added tap water and they lasted a little longer.
but my red light gen still stays on.i have tried to discover the drain as well.i dont have use of a volt meter.or a way to test it.i did read a bulliten from gmc that the light stays on and does not effect the charging system.it was a flaw on pre 76 birchs and only effect it when you have to pass a smog check.also someone here sells apc cable or it could just be a fuse as a couse for the light to stay on even when the engine is running?
I am now replaceing my house batterys
Thanks
Gmc76Birchaven 23'94947
|
|
|
|
|
|
|
|
| Re: [GMCnet] Non-GMC Battery drain. [message #72726 is a reply to message #72705] |
Wed, 03 February 2010 14:38 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
Thanks. I do not have a trailer brake controller or any permanent radio stuff installed. There have not been any radios installed in this vehicle for many months. I put them in temporarily when I want them.
The only non-GM electrical things I have installed are a auto-dimming mirror with compass and an extension to the front accessory power plug that is mounted in the rear. I occasionally power radios and APRS with it. This extension device also has a function that shuts itself off if the voltage goes below 11.9 volts.
Dan has one of these installed in his Vibe and had problems with dead batteries. We sure not sure the two are associated.
I am thinking the BCM somehow monitors battery drain and wakes up occasionally when the load changes or exceeds a certain amount. The static drain appears to be 30 to 40 mils. When this thing kicks in the drain is around 250 mils. I tried disconnecting the battery and watching what happens when I reconnected it. Upon reconnection the load jumped to 600 mils for about a minute and then dropped to 250 mils. A few minutes later it drops to 30 or 40 mils.
Obviously at this point I should disconnect the two non-GM things I installed and go from there. I really would like to know how the computers are suppose to work so I can design my electrical stuff around them.
I put this question up on the Colorado forum but unfortunately most of the users there are non-technical kids interested on how to lower and raise their truck and how big of tires they can squeeze under the fenders. This group is much MUCH, more technical.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: Non-GMC Battery drain. [message #72727 is a reply to message #72712] |
Wed, 03 February 2010 14:43 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
Thanks for the idea. I have a couple of Flukes around here that were made under contract to IBM. I'll look and see if they have that feature.
Thanks
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: Non-GMC Battery drain. [message #72730 is a reply to message #72682] |
Wed, 03 February 2010 15:04 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
Now that is some very useful information. If 30 to 50 ma. is normal then I'm looking for something that periodically cycles off and on. I do not have a GPS. I have an add on auto-dimming mirror with compass. It is the same mirror that GM uses from the same Michigan supplier. I'm beginning to think it goes through some cycle every so often. I'll bet that GM turns theirs off when the key is off. I wired mine hot all the time because ther was already power available up there without having to run a new lead.
What I really would like to know is what wakes up the BCM. I am assuming is somehow monitors for current flow. The reason I say this is if I turn off the interior lights with the dash override switch and wait a few minutes the load goes to 40 ma. Then if I open the door, the load jumps to 250 ma. even though the lights are still over-ridden off and never come on. This is the same 250 ma. draw that I see occasionally when I do nothing.
I just checked and the draw right now is 40 ma. About 1/2 hour ago I checked it and the draw was at 250 ma. I touched nothing between readings. I just go look at the meter.
Thanks for the good info.
Ken
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: Non-GMC Battery drain. [message #72735 is a reply to message #72679] |
Wed, 03 February 2010 17:40 |
Craig Lechowicz
Messages: 541
Registered: October 2006
Location: Waterford, MI
Karma: 0
|
Senior Member |
|
|
Ken said >OK, I'm chasing a battery discharge problem on my Colorado. If I park it for 2 weeks the battery goes dead. A new battery does the same thing.
Ken, I left the Colorado/Canyon team in 2006, but back then, battery replacement mostly due to this issue (some due to less than a good battery supplier, which they changed) was on everyone's radar for being a top 10 warranty item. Strangely, it was higher on Colorado/Canyon than on H3 which share electrical architecture, but have higher option loads. At that time, they had never really gotten to the bottom of it, but I would think they would have by now. Next time I go to the library, I'll look for some bulletins on All Data. I'm not really an electrical expert, but there are lots of modules that "wake up" occasionally and are sometimes less good at going back to sleep. I'm not sure what year your Colorado is, but even if you don't have remote keyless entry, if it's new enough to have Tire Pressure Monitoring, it will have an RKE receiver that polls the tires occasionally (how OnStar can send those reports on Tire Pressures) and OnStar is the other big one for waking up, I think every 10 minutes. Unfortunately, pretty much everyone I knew on that team has moved on with the travails of GM so if there is not a bulletin out there, not sure I will be able to turn anything else up.
Craig Lechowicz
'77 Kingsley, Waterford, MI
|
|
|
|
|
|
| Re: Non-GMC Battery drain. [message #72764 is a reply to message #72735] |
Wed, 03 February 2010 21:21 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
|
Senior Member |
|
|
This is a 2005 WT. No RKE, No Onstar, No TP monitoring.
On a WT if GM could leave it off they did. No right side door key lock, no inside grab handles, no reclining seats, manual windows, etc. If they could have left off the engine and steering wheel I'm convinced they would have done it.
I have installed most of they missing items (locks, seats, handles, etc). with junk yard parts. The auto-dimming mirror with temperature display and compass was new from the manufacturer in Michigan.
Thanks for the help. It is going to be a day or two until I get back to it but I think I'll look at the Collie wiring diagram and see how they powered the mirror from the factory. I threw an ammeter on it today and it only draws 2ma. when the total battery drain is 40 ma. I did not see it when the battery drain was at 250. I can not predict yet when the drain jumps to 250.
Ken
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
|
|
|
|
| Re: Non-GMC Battery drain. [message #72766 is a reply to message #72679] |
Wed, 03 February 2010 21:29 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
|
Senior Member |
|
|
Funny the young Colorado board kids with the computer cars are not technical, but us older GMC dinasaurs are??
Pull one leg of each fuse at a time and measure series voltage with 20v scale to find the highest voltage draw. Then you can narrow down and read mA where the volts are highest.
John Lebetski
Woodstock, IL
77 Eleganza II
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
