Drawing 2.3 amps with Key Off

rickbtbird

Registered User
Today I went to start the 95 after 1 day of a fully changed battery. The battery was dead and it only measure 2.5 volts. So having another fully charged battery I put it in and the car started right up. It's still not changing. With the lights on, the voltage across the battery was only 11.8volts.

What's more alarming is, I disconnected the negative terminal and measured the draw from the battery to the negitive connector and it was drawing 2.3 amps :eek:! I'm guessing I have a bad short somewhere.
 
Tomorrow's Another Day

I disconnect the battery for now. Wife is sleeping and the car is just below the bedroom. Tomorrow late afternoon will be the next time I can get to it.

I was wondering if someone had a picture of a 95's battery connections. I'm still confused :confused: why I have two 4 gage wires coming off the positive terminal.
 
You've obviously got an alt. charging problem if it's only at ~12 volts while running. I think you already knew that based on your other thread... A bad alt. could also be draining the battery. Depending on how the electronics failed, it is conceivable that it could draw current when not running.

As has been said: pull fuses, but if that doesn't narrow it down, take all the wires off the alt and see if your current draw goes away. You've got to take them off anyways to change the alternator.

Vince
 
You've obviously got an alt. charging problem if it's only at ~12 volts while running. I think you already knew that based on your other thread... A bad alt. could also be draining the battery. Depending on how the electronics failed, it is conceivable that it could draw current when not running.

As has been said: pull fuses, but if that doesn't narrow it down, take all the wires off the alt and see if your current draw goes away. You've got to take them off anyways to change the alternator.

Vince
No alternator light comes on at all when the motor is running. This tells me that I either have an open circuit, bad ground, or the alternator/regulator is gone again. Alternator isn't charging for sure. This will be the second one in less then two years. I'll measure the draw again tomorrow and yank out a few fuses and run some diags. These things take time to isolate for a rookie like me. I know for sure last year if I let the car sit for a week the battery won't turn over the car and will have little to no charge. Maybe this new alternator that got installed had a bad regulator in it or something. Too bad it happen while I was on the road because it was a bit expensive.

I'm guessing that I have two 4 gage wires coming from the positive terminal for both the starter and the power distribution box. Way different from my 90SC.
 
>These things take time to isolate for a rookie like me.

Rookies don't know how to check amps draw :)

Walk the alternator into a local auto parts store and ask to have it tested.
 
Rookies don't know how to check amps draw :)

Okay, so I do know some basice electronics but I don't know any parts store that can bench test this alternator. Accoring to the book you have to disamble it to test it off the car, don't you? :confused:

I've got a 110amp alternator on the shelf right now but this car calls for the 130amp. Would I kill it if I used that one?
 
THey can test it, just walk it in to Autozone, Kragens, Shucks or whoever you have and tell them what its off of. They only time they couldn't test 1 for me was on my 2000 Mustang GT that was 2 years old. They just didn't have the right plug. They kept insisting that since it was a 4.6, it should all be the same. ANyways, yeah, take it to them and they can test it. If not, find a local rebuilder and see what they can do to test it.
 
THey can test it, just walk it in to Autozone, Kragens, Shucks or whoever you have and tell them what its off of. They only time they couldn't test 1 for me was on my 2000 Mustang GT that was 2 years old. They just didn't have the right plug. They kept insisting that since it was a 4.6, it should all be the same. ANyways, yeah, take it to them and they can test it. If not, find a local rebuilder and see what they can do to test it.
The 2 closest AutoZones and 1 Advanced Auto couldn't figure out how to test my alternator when I brought it in. I ended up replacing the battery instead and the alternator has been fine.
 
The same thing actually happened to me when I bought the car. I drove it on the test drive and it started fine. I put it on the trailer and when I got it home the next day the car was dead. We charged the battery and it was pulling a draw across after it was charged. I figured a bad leak or something too. Well after talking with a friend at a ford dealer, he said that it keeps power to some of the systems on the car which is why you will see a draw for so long. (not sure about this though) Try checking it after the car has been sitting. I am not sure why my battery died on the trailer home but it hasn't since. (Knocking on wood)
 
Battery voltage with the car running should be between 13.8 and 14.2 volts if not you have a charging problem. Its not uncommon to have a bad alt. cause a parasitic drain on the battery, unhook the alt. and see if your drain goes away.The kid down at Autozone told my buddy they couldnt test his alt (Explorer) so I went down there and showed him how to mount and connect it. I worked there for a short time and a lot of these kids dont know much try another employee to see if they really can.
 
First thing you need to do is check the fuses in the power distro panel under the hood. When you pull the 60AMP fuses you will have some of them showing signs of overheating. A lot of people who own SCs are not aware of this problem. Look where you removed the burnt fuse to see if the fuse block is melted. I had to replace the entire power panel in my 94 because of severe overheating of two 60 AMP fuses. Next check the connection on the alternator. Make sure there is no discoloration. That would indicate overheating. I had this issue on my 90 XR7. I replaced 2 alternators before I found the real problem. The alternator output wire terminated at the starter relay mounted on the fender. The lug was encapsulated in plastic that showed signs of overheating (bubbling plastic). I removed the plastic and found a bad mechanical connection. I removed the old lug and soldered a new lug on. Alternator problem solved.
 
It sounds like you have a dead diode in your alternator. The diodes convert the 3phase ac power generated by the alternator to DC. The diodes act like a one way valve, alternator -> battery.. If shorted, it permits battery -> alternator( huge heater at that point ) = current draw in turn = dead battery..

You will also see approx 12v across the battery terminals when the car is running not 13.8v

If you can find the diodes they are easy to test, replace and inexpensive, however finding them for this mit. alternator has proven to be a chore. Usually any small digital multimeter has a diode test location. By testing across the diode leads, 1 way it should read .5v the other should be 0.
 
the diodes are usually what is wrong.. ( primarily open ), regulators usually are ok. Keep in mind that an alternator generates 3 phase ac power, then it runs all 3 phases thru a diode rectifier bridge to convert ac to dc. The regulator varies the voltage in the armature which inturn varies the output current generated by the field coils then run thru the diodes.

hawked from there

-Tony
 
I did some isolation yesterday evening. The draw is detected from the positive battery terminal wire that is routed to the main fuse box in the engine bay. There's no draw on the one that goes to the starter (thank God).
Pulling fuses in both locations (engine bay and under the dash) didn't prove anything different.

Disconnecting the alternator main leed connection reduced the current draw to .12 amps. My feeling is it should be even less. Resistence is zero in all location I can check.

What caused the alternator to go bad is still a mistery. All I know is the battery went dead late Sunday afternoon. The only thing I did on Sunday was to test the TPS and IAC. I removed and reconnected the connection with the key off. Based on the current draw, if the problem began before Sunday then the battery should have been dead Sunday morning.
 
I did some isolation yesterday evening.

Have you given any particular attention to the ignition switch down on the column yet...? Might want to monitor the draw again while cycling the switch as well as doing a visual inspection to see if the switch is intact.

I'd also consider pulling the power dist. block next to the battery, flipping it over and looking for any melted connections underneath.

Ken
 
Had the same problem on my 93 (nearly new alternator)...to fix the problem I ended up replacing the alternator. Most likely failed from being overloaded from being jump started after sitting for 7 months (dead battery).

David
 
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