When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Parasitic draw TBC fuse 2003 Chevy Express 3500 van
Hello all. 2003 Chevy Express 3500 van
I have a parasitic draw of about 1.9 amps on the TBC fuse. Does anyone know if these problems are the TBC control circuit or the TBC sensor mounted on the throttle body? I don't know if this is an issue that many people have had. Any help from someone who has had these issues would help greatly. I am an electrician and can use a multimeter. It is my cousin's van and I am helping him through this issue. He currently has a kinfe switch style dixconnect on the battery to keep it from being drained. I installed it a few weeks ago but I only have access to the van when he is available. I searched for parasitic draw TBC and found nothing. Thank you.
The TBC Fuses stand for the Body Control Module(BCM) unit. Not the the Throttle Body Control.
My guess is you going to have more success if you look at the fuse box located under the driver seat. Just next to the BCM
Pull one fuse at a time and check if the amp drop. Be careful to put back the fuse at the correct spot.
Most likely your drain is due to an accessory somewhere. Make sure everything is turned off (Sun Visor lights, radio, any third party accessories connected and not nescesssarly visible. etc.....)
Any gadget addition lately ?
Just spent two hours working on this and isolating issues. The 1.9 amp draw from the TBC fuse went away. Looked at all fuses under the seat and no issues. My cousin had wired in a radio that was on all the time and was drawing 0.85 amps. I soldered and heat shrinked a few wires for a rocker switch for the radio. The draw is down to 0.01 amps total. I do not know what happened to the draw that was on the TBC fuse from a month ago. Maybe there was an interior light on while I was troubleshooting a month ago when I first looked at this issue and I just missed it. If the interior lights come off of that fuse box under the seat then that was probably part of the 1.9 amps. The issue is secured for now. At least I am now a member of a Chevy forum for future use. Thank you for the quick reply and for helping me with this van.
Mind you the RAP Circuit would no longer function if he pulled the factory radio out. I had tremendous issues with electrical problems when I first started swapping radios out. I continually had dead batteries and at the time.. it was nearly impossible to deal with as so much other stuff was going on in my life. It was weird, the lights on the door switches were staying on all night. I finally caught on to that after a couple of months. I still do not know what the problem was. Maybe I had an OBDII sensor plugged in, or the cell charger did it, I don't know anymore. I just that I was a mess and the problem of dead batteries just made an impossible situation, that much more impossible. That was hard to deal with.
With all my respect mountainmanjoe... No..... a TBC fuse is actually for the BCM.
Could be more than one. Look at the fuse identification table below for a GMC savana 2004
No 11, 16, 18 ,19 and 24
The one you referring to is the no 5 or 13 ; Trailer wiring harness.
Well that's just unbelievably stupid. They call it "BCM" everywhere else on wiring diagrams and service manuals. I guess that would be too consistent, so in the fuse box they gave it a name that is used for trailer brake controllers. Just so you don't think I'm making it up: https://www.google.ca/search?q=tbc+brake
I guess I stand corrected. Thank you for pointing it out pomerlo.
Mind you the RAP Circuit would no longer function if he pulled the factory radio out. I had tremendous issues with electrical problems when I first started swapping radios out. I continually had dead batteries and at the time.. it was nearly impossible to deal with as so much other stuff was going on in my life. It was weird, the lights on the door switches were staying on all night. I finally caught on to that after a couple of months. I still do not know what the problem was. Maybe I had an OBDII sensor plugged in, or the cell charger did it, I don't know anymore. I just that I was a mess and the problem of dead batteries just made an impossible situation, that much more impossible. That was hard to deal with.
I know this old but in case you happen to see it @dberladyn … I’m in the exact same boat as you described. Our van is dead all the time and it’s making life so hard on top of other things. We had a lot of aftermarket electronics installed by a business that has since went out of business. We know why now! Our normal mechanic has had it 3 times and took out some of the accsssories but now it’s worse. It’s dead after 24 hours now, used to take 10 days. Also, the radio randomly goes off and won’t work, then turns on, and back and forth. My husband thinks it’s related to the box under the driver’s seat but he’s in his super busy season of work and hasn’t had the time to devote a day or several days to it.
Could anyone direct me to a tutorial on how to troubleshoot this myself? No electronics places will touch it since they didn’t do the install. I’ve tried several mechanics and they all say they hate electronics and don’t want to deal with it. I’m a reasonably intelligent person and grew up working on things with my dad. Can I try anything? It’s a huge pain!!
Last edited by J Beck; July 3rd, 2024 at 11:47 PM.
June 18th, 2020, 12:44 PM
Parasitic draw TBC fuse 2003 Chevy Express 3500 van
