2000 GMC K2500 - parasite draw
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=204897
Printed Date: 22 Jan 2025 at 5:04am
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Topic: 2000 GMC K2500 - parasite draw
Posted By: Coke-in-MN
Subject: 2000 GMC K2500 - parasite draw
Date Posted: 10 Jan 2025 at 11:43pm
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Dang truck has a parasite draw of about 700 MA and kills both batteries in a few days . Checked early spring and alternator showed a bad diode so replaced the full unit . Then find out it still kills batteries . Next the fuse blew to ECM somehow and no power to fire plugs and no fuel pressure . Had local shop replace fuel pump and install new straps on fuel tank as old ones were rusted to scrap . Needed to truck to plow a week or so back - all the time i was plowing the headlight alarm sounded they were on / key in ignition ding . Now as has auto on headlight switch since I got the truck in 2000 I have always just left switch in auto position . Turning it to off alarm still sounds until key is removed completely from column. About ready to look for another truck as body rusting out , frame rusty , front differential brace to frame rusted off frame, tale gate rusted , hinge points rusted off box , bed rust through in many spots . 90,000 miles and wonder if it's worth dealing with . What is a real mark of quality is front bumper has holes rusted through it i several places . ONE OF GM good ideas . I found out when ordering part when I rebuilt the transfer case , GM put 3/4 running gear under a 1/2 ton frame then spacers under cab to raise it up higher and called it a 3/4 ton ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Replies:
Posted By: DMiller
Date Posted: 11 Jan 2025 at 3:59am
| Sad times Coke. |
Posted By: Thad in AR.
Date Posted: 11 Jan 2025 at 5:25am
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Coke I just traded one of those off. A light duty 3/4 ton. Mine had a little over 600000 miles on it. Wore out from front to rear but was a very good truck. Was starting to have wiring issues as well. |
Posted By: Clay
Date Posted: 11 Jan 2025 at 8:07am
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2003 Chevy Express had power draw. Dash lights would not turn off. Pulled fuse #15. That solved the problem. Replaced the light switch but the dash lights remain on. Now, when driving at night, I rest one of free blue hand held flash lights, from Harbor Freight, against the instruments. Works great.
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Posted By: Ed (Ont)
Date Posted: 11 Jan 2025 at 8:29am
I know this is not solution but may help in the short term. Install a master disconnect at the battery. Shut it off when you think it will be parked for day or two. It's not a bad idea on any vehicle. Have you checked both batteries to see if they are good? Looks as if you have done some pretty careful diagnostics. 
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Posted By: jaybmiller
Date Posted: 11 Jan 2025 at 8:39am
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nuther problem.. everyone just HAS to have all the electronic bling , 'computers' and alarms and GPS and ONStar and ... well guess what , they're all ON 24/7. neighbour borrowed my ancient battery charger as, like coke, BOTH batteries died in a week, diesel Chevy...... ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: Ed (Ont)
Date Posted: 11 Jan 2025 at 8:48am
| I had a 99 GMC 2500. Loved it. Did a great job for me and just sold it a couple years ago. Still miss that truck. One problem these had was the fuse panel under hood would turn green underneath. Lift it up and check it. Was a common problem on those years of trucks and vans. My buddy that is a mechanic at a GM dealership clued me in on that one. GM still had those available in parts a few years ago and the price was very reasonable. |
Posted By: jaybmiller
Date Posted: 11 Jan 2025 at 9:51am
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hmm 700 ma is a LOT... put meter to read it and then start puling fuses. eventually it'll drop and THAT is the circuit to look at. IF after pulling all zillion fuses there's still a drain, corroded fuse panel...... I rebuilt a dodge one, years ago, on my birthday,was going to go out for dindin... for the 'contractor' after he'd paid a guy to fix it. yeah, I FIXED it but never got paid ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: Coke-in-MN
Date Posted: 11 Jan 2025 at 1:28pm
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All started a year back , replaced alternator and main battery . Still killed batteries , left trickle charger / maintainer hooked up and could still drive it when needed . Someone unplugged charger , stoned plow battery dead , main battery came back to life , then went dead again and no start , when found the ECM fuse blown and figured fuel pump in tank was bad (corrosion on wires on pump in tank). So now 2 new batteries and sat for 3 days in the extreme cold and both batteries froze - after 3 days in heated shop and trickle charge got them back to 12.9 Volts The indicator light for the shift position in dash does not light up so now guess what gear your in . Next was the ding / ding when driving with headlights on .... Heck my 76 GMC dump truck or the 66 White dump truck electrical are easy and can be fixed with no problem - but this has got me ready to have a fire sale . ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: Les Kerf
Date Posted: 11 Jan 2025 at 2:31pm
On a vehicle which appears to be on its last legs, such as the original poster described, this may well be the most economical solution.
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Ed (Ont) wrote:Posted By: jaybmiller
Date Posted: 11 Jan 2025 at 2:35pm
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most economical solution is to put ammeter in and pull fuse to locate WHERE the drain is coming from. This costs you nothing, 400A disconnect is a few bucks( oops .need 2, two batteries....)_I'm assuming batteries are NOT in parallel, have an 'isolator' between them ? ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: Coke-in-MN
Date Posted: 11 Jan 2025 at 3:34pm
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2 batteries are not isolated from each other - evidently later configurations of snow plow prep package are . This uses the starter solonoid lug as common point to charge both batteries but use to have a fuse in the lead to supply plow solonoid . Eliminated the fuse first year of use when fuse blew and no dealer had a 150 Amp fuse in stock. Debating of isolating the plow battery - but still need some way to charge it so large diode in line might be only way . Then a solonoid so plow battery could be used if needed to start truck . ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: jaybmiller
Date Posted: 11 Jan 2025 at 3:47pm
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OK, 2 in parallel, so the weak one WILL drain down the other... Best if BOTH batteries same make/model/CCA/etc.... Use a $50 'battery isolator'. It's two diodes in an aluminum shell. 3 studs... outer ones go to batteries, center goes to alternator. Power from alternator flows through diode to the batteries. diodes are 'one way' device, current ONLY flows, yeah, one way.... Normally 1st battery does 'truck stuff', 2nd powers the plow motor/pump. Some guys will add a 'starter solenoid' between the +posts of the batteries. With flip of a switch batteries are now connected,so one can 'boost' the other. at the end of the day , you really need to find out what's draining the battery. until then , whatever you do is a 'bandaid'. ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: Tbone95
Date Posted: 11 Jan 2025 at 4:14pm
Well, given he’s had the truck 24 years I’m guessing that’s not it. 
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Posted By: jaybmiller
Date Posted: 11 Jan 2025 at 4:59pm
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Odds are it'll be corrosion at fuse panel under the hood OR someone added something ,live to battery. 700ma is a LOT, so not 'normal' things like radio, alarm BUT a GPS unit in OBD-II data connector could do it..... heck a 'battery tender' would maybe ,almost not recharge at that rate.. I'd take 1/2 hour, pull fuses ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: HudCo
Date Posted: 11 Jan 2025 at 7:39pm
| those radios have been known to have the memory drain the battery also need to check awps draw before the computer goes to sleep and after |
Posted By: D19allisowner
Date Posted: 11 Jan 2025 at 8:20pm
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MY 2004 chevy had a bad radio and was running the battery dead after 2 days. ------------- If you choose not to decide you still have made a choice. |
Posted By: wade89
Date Posted: 11 Jan 2025 at 9:00pm
| Had similar issue. Ended up bein the backlighting to the power window/lock switches in the door. |