parasitic draw
11-14-2018, 12:00 AM
#1
Heel & Toe
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parasitic draw
I got a parasitic draw, after 3 days battery dead. I've check all the fuses and they all good. 2004 C5 Corvette standard. Don't know where to go from here.
11-14-2018, 12:57 AM
#2
Drifting
It is not possible for a fuse to cause a parasitic draw. If you use Google and search "parasitic draw in a C5 Corvette" you will see the many possible causes and possible solutions. It has been discussed many times as this is a fairly common problem. Perhaps you should consider taking the car to a trusted shop, NOT a dealership.
11-20-2018, 11:35 AM
#4
Don't know if this will help you but I found that the glove compartment light was staying on draining my battery. Seems that the door will kind of droop just enough so the switch is not fully compressed. I just took a self adhesive felt pad( the kind you use for the bottom of a chair leg ) and positioned it so it pushed in the switch when closed. Seemed to correct my issue. I do keep a CTEK battery tender on mine at all times now.
11-20-2018, 12:37 PM
#5
Melting Slicks
Had a similar problem recently. Turned out that my starter went bad. It was explained to me that the starter continued to draw on the battery even after the car started causing the battery to go dead. Replaced the starter. Problem solved.
11-20-2018, 02:03 PM
#6
Instructor
My wife’s ‘99 vert had this problem about a year ago. We went through several batteries over a period of about 18 months. One evening, out in the garage, I heard a hum from inside the car. Followed the sound, and something I’ve not yet identified in the passenger seat was humming and producing a slight vibration. Since moving the seat is never really necessary, I loosened the mounting, and unplugged the connectors powering the passenger seat. Since then, problem solved.
11-20-2018, 03:24 PM
#7
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
Lets do this... On the UNDERHOOD FUSE BOX, there is a B+ connection on the side of the fuse box. You will find TWO battery cables bolted to that B+ stud. One is the battery FEED directly from the battery, and the other one is a FEED THROUH that supplies power to the PASSENGERS FOOT WELL FUSE BOX.
NOTE/WARNING! Be careful!! This is a HOT AT ALL TIMES wire!
If you disconnect those wires, you can use the wire from the battery terminal to power either the engine compartment fuse box OR the Passengers Well Fuse Box separately. That will allow you to see which fuse box is drawing the excessive current. The designed spec for the C5 is very close to 2 milliamps.
You can also insert the AMP Meter between the HOT battery cable and the box that you are testing. Once you determine what fuse box is drawing excessive current, you can concentrate your efforts on finding the circuit in that specific fuse box that is drawing the excessive current.
Give that a try and see how you make out. Let us know what you find.
My guess is that you will be finding the problem in the passenger foot well box.. Something is staying on that SHOULD be turning OFF. Take a look at the car at night to see if any lighting is staying on.. That is an easily missed issue but a very simple one to solve!!
Bill
NOTE/WARNING! Be careful!! This is a HOT AT ALL TIMES wire!
If you disconnect those wires, you can use the wire from the battery terminal to power either the engine compartment fuse box OR the Passengers Well Fuse Box separately. That will allow you to see which fuse box is drawing the excessive current. The designed spec for the C5 is very close to 2 milliamps.
You can also insert the AMP Meter between the HOT battery cable and the box that you are testing. Once you determine what fuse box is drawing excessive current, you can concentrate your efforts on finding the circuit in that specific fuse box that is drawing the excessive current.
Give that a try and see how you make out. Let us know what you find.
My guess is that you will be finding the problem in the passenger foot well box.. Something is staying on that SHOULD be turning OFF. Take a look at the car at night to see if any lighting is staying on.. That is an easily missed issue but a very simple one to solve!!
Bill
Last edited by Bill Curlee; 11-20-2018 at 03:25 PM.
11-20-2018, 03:29 PM
#8
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This video will explain the "procedure" if you've never performed this test...."voltage drop" testing across the fuse is best...if your DVOM has a millivolt scale that's great !!
The following 2 users liked this post by C5 Diag:
Doug1 (11-23-2018),
photonhunter (12-22-2018)
11-20-2018, 03:31 PM
#9
Former Vendor
We see this problem often, and there are many possibilities. One that is not expected is that corrosion will occur on the circuit board in the seat switch. It may not cause the seat motor to run, but it can cause a slow drain to ground. We see it most often in convertibles since they are more likely to get moisture in the switch from getting caught in the rain with top down or weatherstrip leaking.. Happens in coupes also, just less frequently. Open your LH window in the rain or with heavy dew on the car and see where the water drips! If you remove the switch from the seat and GENTLY open it, look for any corrosion on the circuit board. If you see any, that may be the issue. Just one of many possibilities.
11-20-2018, 03:41 PM
#10
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
We see this problem often, and there are many possibilities. One that is not expected is that corrosion will occur on the circuit board in the seat switch. It may not cause the seat motor to run, but it can cause a slow drain to ground. We see it most often in convertibles since they are more likely to get moisture in the switch from getting caught in the rain with top down or weatherstrip leaking.. Happens in coupes also, just less frequently. Open your LH window in the rain or with heavy dew on the car and see where the water drips! If you remove the switch from the seat and GENTLY open it, look for any corrosion on the circuit board. If you see any, that may be the issue. Just one of many possibilities.
The seat multifunction switch return springs can also wear and not re-center the switch into the (middle) "OFF" position causing the seat to also run continuously. The seat motor circuit is protected by a circuit BREAKER and it will trip and reset until the battery is DEAD!
11-22-2018, 10:13 AM
#13
Safety Car
I had the exact same problem, replaced my alternator, only problem is, I didn't do a search on here over the potential problems of the local auto parts alternators, I spent $160, now I have the "charge system fault message", aggravating. Hope you don't get that.
Don't forget to fully charge your battery, I'm sure you did that though.
Just ordered correct alternator from amazon, $380(real good price from what I have seen)
Autozone told me on the phone they would refund/return the part, we'll see how that goes.
update: replaced alternator yesterday with the one I gave a link to, works great, no more error messages and Autozone gave full refund plus money for my original core.
Last edited by Doug1; 12-02-2018 at 09:36 AM.
01-04-2019, 05:56 PM
#16
I had the EXACT same issue as 37pat did......with a brand new battery. I sat in my car one day, windows up, engine off, no radio, etc.....and I kept hearing a hum. I zeroed in on the noise and found it coming from beneath the passenger seat. Turns out it was the lumbar support, etc. motor was constantly engaged. I also just decided to disconnect the switch and no more battery drain. I suspect it's the switch itself. One day I'll plunk down the $250 and buy a new switch. Until then my passenger (wife) can accept her seat the way it is.
