The other day my wife called saying the car wouldn't start. I hooked up jumper cables but is didn't start immediately. I disconnectd the negative cable from the battery while keeping the jumper cable attached to the negative cable. (This removes the battery from the circuit so the good battery is not trying to charge up the old battery while also trying to turn the starter. It eliminates the waiting period.) The started and I drove the car home. I checked battery voltage at that point and it was 12.73. Clearly the charging system was working fine. The next morning the car wouln't start. Checked the battry voltage and it was 12.59. The battery was not the problem. Used a clampmeter on the positive battery cable to look for parasitic draws. With the ignition off, no current being drawn. With the ignition in the "ON" position but nothing on (no fans, chargers, radio, lights, etc.) there is a draw of over 3.5 amps, way more than you would expect from powering up ecu, relays, etc. This persists indefinitely so it is not a short draw from the fuel pump and the fuel pump is not continuing to run. In fact, the current starts out smaller and slowly builds up until it levels off as high as 3.73 amps. After 20-30 minutes of testing circuits, the draw was ~3.54 amps, probably because the battery was wearing down.
I started pulling fuses to identify what circuit the draw was coming from. Eventually, I found the largest individual draw of ~2.4 amps in fuse position #18 labelled guage. Web info says this fuse serves "Gauges and Meters, Back-Up Lamps, Charging System, Power Door Locks, Power Windows, Sunroof, Air Conditioning, Cruise Control." My car does not have power locks, windows or sunroof so hopefully I can eliminate those posibilities.
So at this point, I am thinking that in one of those circuits I either have a faulty component with an internal short, or a wire that is rubbed bare and shorting to ground.
My questions are these:
1) Has anyone else experienced anything similar and found the source?
2) Barring that, does anyone have a suggestion for what component(s) I should check first?
3) Does anyone have suggestions on how to go about chasing this down further? Pulling fuses and looking for changes on the Clampmeter is easy enough but I'm a little lost as to what the next step should be.
I'm proficient with a DMM and I have lots of experience fixing mechanical issues (to the point of major engine overhaul) but much less experience with mystery eletrical issues.
Any help or suggestions would be greatly appreciated.
Large parasitic draw when ignition in "ON" position. Wont crank.
Re: Large parasitic draw when ignition in "ON" position. Wont crank.
3.5 A seems like a lot, but it could be, I never measured it Shouldn't make much difference given batteries are rated multiple hundreds of cranking amps, and at least in the 03-08s, the gauge fuse (and all the stuff powered by relays it activates) gets disconnected when you turn from ON to Start
Not sure what year yours is, and welcome to genvibe, btw.
If there's no current draw when the key is off, and the charging system is working, then I'm not sure why the parasitic draw would take a charged battery and leave it unable to start the car after sitting overnight. How low does the battery voltage drop while actively engaging the starter? Any difference in that voltage when measured on the battery terminals themselves, and the battery cable ends> Any difference when measured between the battery positive terminal and the engine/chassis ground (instead of the battery negative terminal) ?
Not sure what year yours is, and welcome to genvibe, btw.
If there's no current draw when the key is off, and the charging system is working, then I'm not sure why the parasitic draw would take a charged battery and leave it unable to start the car after sitting overnight. How low does the battery voltage drop while actively engaging the starter? Any difference in that voltage when measured on the battery terminals themselves, and the battery cable ends> Any difference when measured between the battery positive terminal and the engine/chassis ground (instead of the battery negative terminal) ?
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andrewclaus
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- Joined: Tue Oct 03, 2017 6:38 pm
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Re: Large parasitic draw when ignition in "ON" position. Wont crank.
Concentrating on fixing the no crank problem, only when the battery's in the circuit, leads me to think there's something wrong with the battery under cranking load. I suggest bringing it to a parts store and have them do a load test on it. How old is the battery?
Then work on the load on the Gauge circuit. It won't be a short to ground, that would blow a fuse. I agree that load won't cause cranking failure, and you know the cranking system components all work because of the jumper cable test.
And you might want to check your clamp-on meter reading with an ammeter in series from negative terminal to ground. What's the full-scale range on the clamp-on meter? It may not be accurate if it's low on the scale.
What year and model is your Vibe?
Then work on the load on the Gauge circuit. It won't be a short to ground, that would blow a fuse. I agree that load won't cause cranking failure, and you know the cranking system components all work because of the jumper cable test.
And you might want to check your clamp-on meter reading with an ammeter in series from negative terminal to ground. What's the full-scale range on the clamp-on meter? It may not be accurate if it's low on the scale.
What year and model is your Vibe?
Re: Large parasitic draw when ignition in "ON" position. Wont crank.
Hi Joatmon and Andrewclaus,
thank you for your replies. I am embarrassed to say I made a mistake in my earlier assessment. I did find that not everything was turned off. The heater fan was on low and I didn't hear it at first. After after really getting everything turned off, the lowest current draw in the "ON" position was ~1.2A. Higher than I'd want, but perhaps not abnormal. Unfortunately it still wouldn't crank. If I bypassed the ignition circuit and shorted battery battery voltage directly to the starter solenoid I could *sometimes* get a click but still no crank. This made me suspect a bad starter. I took it off the vehicle and tested it again, it clicked but didn't spin. This suggested I was on the right track but wasn't definitive. So I tested it with another battery and it spun right up.
So... now it was either a weak battery in the vehicle or a weak starter that would work without a load but not in the vehicle. So I renstalled the starter and swapped out the battery temporarily with a Civic battery (smaller) that I had on hand. It started right up. So problem identified, right?
A couple days later I took the battery in to AZ to have it load tested to confirm. They declared it a good battery. So at this point I was going to put the original battery back in and see what happened. The only thing I could figure was maybe I had a bad connection somewhere and that after all my fiddling and parts R&R maybe I had resolved the problem.
And here's where it gets sad. The next day I got a call from my wife saying the car made a really bad sound and she was afraid to drive it. Turns out something in the manual transmission has failed catastrophically (not the clutch) and it will no longer go into any gear. But it runs great!
It may be the end of the road for this vehicle. It has served us well but we were already planning to sell it because we need something bigger. It is a 2003 base FWD model with ~270,000 miles. The cost to have someone rebuild the trans is likely more than I could sell the car for. Even if I rebuilt the trans myself the parts alone would be ~$800 and I don't have the time. Last fall I did an almost complete rebuild of the engine & also replaced the radiator & gas tank, so it is especially frustrating.
If I can get a cheap used trans I will install it and sell it. If not, I will try to sell the parts. So much of it is practically brand new.
Anyway, thanks again for the help.
thank you for your replies. I am embarrassed to say I made a mistake in my earlier assessment. I did find that not everything was turned off. The heater fan was on low and I didn't hear it at first. After after really getting everything turned off, the lowest current draw in the "ON" position was ~1.2A. Higher than I'd want, but perhaps not abnormal. Unfortunately it still wouldn't crank. If I bypassed the ignition circuit and shorted battery battery voltage directly to the starter solenoid I could *sometimes* get a click but still no crank. This made me suspect a bad starter. I took it off the vehicle and tested it again, it clicked but didn't spin. This suggested I was on the right track but wasn't definitive. So I tested it with another battery and it spun right up.
So... now it was either a weak battery in the vehicle or a weak starter that would work without a load but not in the vehicle. So I renstalled the starter and swapped out the battery temporarily with a Civic battery (smaller) that I had on hand. It started right up. So problem identified, right?
A couple days later I took the battery in to AZ to have it load tested to confirm. They declared it a good battery. So at this point I was going to put the original battery back in and see what happened. The only thing I could figure was maybe I had a bad connection somewhere and that after all my fiddling and parts R&R maybe I had resolved the problem.
And here's where it gets sad. The next day I got a call from my wife saying the car made a really bad sound and she was afraid to drive it. Turns out something in the manual transmission has failed catastrophically (not the clutch) and it will no longer go into any gear. But it runs great!
It may be the end of the road for this vehicle. It has served us well but we were already planning to sell it because we need something bigger. It is a 2003 base FWD model with ~270,000 miles. The cost to have someone rebuild the trans is likely more than I could sell the car for. Even if I rebuilt the trans myself the parts alone would be ~$800 and I don't have the time. Last fall I did an almost complete rebuild of the engine & also replaced the radiator & gas tank, so it is especially frustrating.
If I can get a cheap used trans I will install it and sell it. If not, I will try to sell the parts. So much of it is practically brand new.
Anyway, thanks again for the help.
Re: Large parasitic draw when ignition in "ON" position. Wont crank.
Update: My vibe is on the road again!
I ended up repairing the transmission myself. It was the common bearing that often fails in the C59 5-speed manual transmissions. I caught it early and there was no other internal damage. My only costs were the bearing, plus seals & fluid (and , of course, my labor.) There were several helpful youtube videos that walked me through the process. The service manual posted online at https://www.madstyle1972.com/Repair/ was also very helpful.
Once I got the transmission repaired I put the original battery back in it and it started right up. I still don't know what the starting problem was or how I resolved it. My best guess was that it was a bad electrical connection (battery, starter, ground, fuse, relay, ignition switch) that I somehow reset when I was chasing down the problem.
In any case, it's starting & running great now. If anyone wants to buy a 2003 base FWD with 251k miles please let me know. Its got a completely rebuilt engine (with new timing chain, waterpump, oil pump, etc.), a partially rebuilt manual transmission in great shape, a brand new gas tank and radiator, and various other parts that have been replaced along the way. A/C and heater work great. The only thing I can think of that doesn't work as it should is the CD player, but the stereo works fine.
PM me if you're interested.
I ended up repairing the transmission myself. It was the common bearing that often fails in the C59 5-speed manual transmissions. I caught it early and there was no other internal damage. My only costs were the bearing, plus seals & fluid (and , of course, my labor.) There were several helpful youtube videos that walked me through the process. The service manual posted online at https://www.madstyle1972.com/Repair/ was also very helpful.
Once I got the transmission repaired I put the original battery back in it and it started right up. I still don't know what the starting problem was or how I resolved it. My best guess was that it was a bad electrical connection (battery, starter, ground, fuse, relay, ignition switch) that I somehow reset when I was chasing down the problem.
In any case, it's starting & running great now. If anyone wants to buy a 2003 base FWD with 251k miles please let me know. Its got a completely rebuilt engine (with new timing chain, waterpump, oil pump, etc.), a partially rebuilt manual transmission in great shape, a brand new gas tank and radiator, and various other parts that have been replaced along the way. A/C and heater work great. The only thing I can think of that doesn't work as it should is the CD player, but the stereo works fine.
PM me if you're interested.