idea of what relays migth be staying powered at shutdown to kill bat on 2000 gmc yuko

[Soundguy]

wifes yukon has good bat and good alt.

once in a blue moon ( very rarely.. ) the thing will kill the bat overnight. like maybee 2 times a year.

Something is staying on and powered obviously... just trying to figure out some ideas of relays that migth be sticking and staying powered that would have a significant draw to kill a good bat overnight.

ideas?

thanks

 

[puckgrinder85]

A lot of things can do this obviously, but the most common one I've seen on SUV's is the rear wiper being bound up. The motor shaft tends to corrode in its bore and will hold the wiper in any place other than its "parked" home position. This will draw on a battery even when the ignition is off.

 

[Soundguy]

double doors on this model. don't think it has a wiper but will check, thanks

 

[Streak]

pretty easy to tell. you WILL get a small parasitic drain on the batt all the time from the electronics, but if you disconnect the - batt terminal and put a test light between the cable and battery, you will initially get bright light, but its should dim down fairly quickly. IF it stays bright, you have a substantial draw somewhere. Pull the fuses one at a time to pinpoint the circut its on. A big offender is the glove box light, and sometimes the under hood light. check to see if its staying on for some reason. Probably NOT a relay..................
FYI, if you disconnect the batt you will lose radio stations, computer memory, etc etc........ Odd that it only does it a couple times a year. Maybe on occasion she's not shutting the door all the way leaving the dome on??

 

[Soundguy]

see that's the issue. I know the electrical diagnostics for load detection. but the thing does it like 1-2x per year. if it did it daily.. I could find it.

since i don't know it's doing it till the wife calls me and the bat is already dead. when i get there to charge it or jump it. whatever was drainging it has already 'fixed' itself by them... which makes me think a relay..

ie. it stays on draining till voltage gets low enough that coil drops out. once it drops out. laod stops and it sets there dead waiting for a charge or jump. then poof.. 4m later it might do it again. makes me think some electrical circuit is staying on at shutdown, and that is keeping a relay energized. as said. when V drops below a threshold for logic or pull in for the coil. it all hits the floor and acts normal and nice so near impossible to tell.

I had a dodge that had a broke clip int he glove box that was allowing a full time drain. took a while but we found it. this one is a booger though. it's so infrequent.. that it's not an issue itself... it's just that it decides to do it the 1 day of the year when no ther vehicle is there, the wife is late, etc..e tc. so darn inconvienient.

in reality.. since it is a GM product...... I blame myself for owning it.

 

[grsthegreat]

i have a 12 volt solenoid that powers a set of 1/0 cables that run to the rear of my F350 to power a winch i occasionally use. If i forget to turn off the switch that powers that solenoid....dead battery in a day or so. All im powering is a solenoid, but it dumps the battery.... even without the winch hooked up.

Man, there are SOOO many relays on newer vehicles......who can guess. Ive even seen occasionally that my radio in the Chevy van wont auto shut down when key is removed and door is opened. the radio just keeps playing. I have to reinsert key and restart and shut down rig to get it to shut down. happens 2-3 times a year at most. Something like that could kill it. Also, some cars have auto headlight timed relays...if that fails, the lights stay on .

 

[puckgrinder85]

pretty easy to tell. you WILL get a small parasitic drain on the batt all the time from the electronics, but if you disconnect the - batt terminal and put a test light between the cable and battery, you will initially get bright light, but its should dim down fairly quickly. IF it stays bright, you have a substantial draw somewhere. Pull the fuses one at a time to pinpoint the circut its on. A big offender is the glove box light, and sometimes the under hood light. check to see if its staying on for some reason. Probably NOT a relay..................
FYI, if you disconnect the batt you will lose radio stations, computer memory, etc etc........ Odd that it only does it a couple times a year. Maybe on occasion she's not shutting the door all the way leaving the dome on??

That's a very down and dirty test and probably wont get you anywhere but confused. You have no idea how much current its taking to light the filament in the test light and you need a solid number to start with. You really must connect a DVOM inline and allow the modules to all timeout which on some vehicles is usually 20-30 minutes, sometimes longer. Yes, intermittent crap like this will drive you bonkers but it happens on all sorts of vehicles. For what the problem is I'd buy a portable jumper pack and teach your wife how to properly use it. Yes its a ****** deal but hey, at least she'll have a sense of security that if it does happen in the middle of nowhere she can do it herself. Did you check the rear wiper motor arm/ motor shaft?

 

[grsthegreat]

also....check what the current value of the rig is...maybe shell like a newer rig hehe

 

[Soundguy]

exactly.

might be something not turning off with the key switch. seems gm is in the business of selling bad key switches according to the news.

i have a 12 volt solenoid that powers a set of 1/0 cables that run to the rear of my F350 to power a winch i occasionally use. If i forget to turn off the switch that powers that solenoid....dead battery in a day or so. All im powering is a solenoid, but it dumps the battery.... even without the winch hooked up.

Man, there are SOOO many relays on newer vehicles......who can guess. Ive even seen occasionally that my radio in the Chevy van wont auto shut down when key is removed and door is opened. the radio just keeps playing. I have to reinsert key and restart and shut down rig to get it to shut down. happens 2-3 times a year at most. Something like that could kill it. Also, some cars have auto headlight timed relays...if that fails, the lights stay on .

 

[Soundguy]

havn't been home yet to do so.. but will..

we do have a jumper pack.. and I got it for her 4m ago when it pulled this the last time. so it's only happening like 3x a year. just annoying as all get out.

i hear ya about the modules timing out.

when i went thru with this in my dodge truclk.. did that. in that one. just about everything timed out, including the lil deal that turns the dome light off after door is open a while, takes 5m.. that's how i finally found the glove box light. by accident. was testing at night and noticing the glow thru the door seam..

That's a very down and dirty test and probably wont get you anywhere but confused. You have no idea how much current its taking to light the filament in the test light and you need a solid number to start with. You really must connect a DVOM inline and allow the modules to all timeout which on some vehicles is usually 20-30 minutes, sometimes longer. Yes, intermittent crap like this will drive you bonkers but it happens on all sorts of vehicles. For what the problem is I'd buy a portable jumper pack and teach your wife how to properly use it. Yes its a ****** deal but hey, at least she'll have a sense of security that if it does happen in the middle of nowhere she can do it herself. Did you check the rear wiper motor arm/ motor shaft?