parasitic drain (6 amp) on batt 1 fuse. What could this be?
That is a huge current drain if that number is correct. Things like the blower motor or headlights draw that kind of current. To see if the alternator is causing it remove the main wire to it and see if the current drops then. It is wise to first disconnect the negative battery lead before working on that wire as it is HOT at all times and sparks will fly if that lead touches ground while the battery is connected. Keep the connection isolated from things. If the trouble isn’t with the alternator then disconnect other main fuses to see if that helps pin down the location further more.
What do you mean by “1 fuse”?
Current draw seems to be on batt 1 fuse. Do you know what is on that circuit ?. Have disconnected alternator. That wasn’t the problem. Initially started as mild parasitic draw ( battery would lose charge if not driven daily. Now car won’t start even with jump. Battery voltage drops to 10-11 volts within minutes of connecting battery, No fuses are blown. I’ve charged battery and removed batt 1 fuse to see if battery will hold charge overnight. Any advice would be helpful.
On fusebox cover this fuse is labeled as batt 1. It’s a 50 amp fuse. It showed about 6 amp draw on testing. I don’t know what’s on this circuit, but that doesn’t seem to be the problem, or at least not the only problem. I removed fuse,disconnected and charged battery. When I hooked up battery voltage dropped to 11…4 in 15 minutes. Listened for sounds, heard none. Looked inside vehicle, Check engine light not going out. Passenger side seat belt light stays on.
Sounds like the battery has failed, shorted cell. A good fully charged battery won’t drop to 11.4 volts in 15 minutes.
did it hold charge?
IF there is no current drain, that means the battery is dead.
After looking at some data it shows Fuse 1 supplies power to fuses in the dash fuse panel. While monitoring the current drain, remove fuses in that panel one at a time, in order to help pin down which fused circuit is causing the trouble.
Thanks, I’ll try that next.
The 6 amp draw – over some time – may have damaged the battery beyond repair. A battery load test would confirm. It sounds like the “batt 1” fuse is just the main fuse for most of the car’s circuits, so knowing the current through it isn’t going to be very helpful in figuring out the cause.
However, one test you should make is whether removing that fuse stops the current draw on the battery. To determine the current draw on the battery, what I do is connect an amp meter in series with the battery’s negative connector. Note that is possible to damage your amp meter if the current draw exceeds its rating. I start with an un-powered amp meter I have that just deflects a magnetic needle as a measure of the current. If that’s under 10 amps, then I connect up my DVM in 10 amp mode for a more accurate reading.
To determine which circuit is causing the draw, that’s best done by removing fuses from the fuse panel one at a time while monitoring the draw on the battery negative, as above. Removing one of those fuses should end most the entire 6 amp draw to stop. If you have one of those laser-guided infrared temperature detectors, that can make it easier, as the fuse with the draw will have the highest temperature. This could be an excuse to buy one … They’re relatively inexpensive.
That fact that it is 6 amps will make it easier to detect. Normal parasitic draw is rarely over the 50 - 100 mA range. You have 6000 mA, way beyond normal. Anpother way to look at it, 6 amps * 12 volts === 72 watts. That should be producing either some heat , light, or some motion somewhere in the car. For draws that big I usually suspect aftermarket stereo equipment, or alarm system malfunctions. If you have either of those, try disconnecting them and see how that affects the draw.
thanks for your input. It’s really appreciated.