Alternator wires?

Topic: Alternator wires? (Read 7258 times) previous topic - next topic

Alternator wires?

Reply #15 – July 30, 2011, 11:30:51 PM

Quote from: thewestie;364333

I'm chasing a parasitic loss. With the alt plugged in I'm pulling 12.5 volt with a meter in line with the pos post. Unplugged it drops to .43 volts. Wanted to know what's what with the plug before I jump on the guy who rebuilt my alt

You Need to do a draw down test before condemning a part. All alternators draw down on walk away. Check the draw down amperage not the voltage.

Alternator wires?

Reply #16 – July 31, 2011, 12:35:11 PM

be careful,, remember this thread? (in my diy link)
http://www.foxtbirdcougarforums.com/showthread.php?t=15802&highlight=3g

As far a I know, we as a group have still not confirmed the wiring of the three variations that ford used to wire in the shunts for the buttstuffog cluster. In the above link, the guys car burnt to the ground as a result of a 3g swap.,, just sayin.

I woulnt suggest (for the moment) checking amperage as tom said for the simple reason,, You say you have a draw of 12v potential. With that much draw, and if a regular test light "in place of the meter" glows easily and bright, your amperage on the draw my exceed the max ampacity of your meter..... IE- you may smoke check your meter if the amps in this suspected draw is higher than what your meter allows.

Typically people deal with a parasitic draw of milli-volts like tom mentioned but in your case you state you have a full blown battery voltage showing up,, I would be cautious so you dont smoke something.

In cases where the parasitic draw is milli volts, you can borrow your instrument panel headlamp switch light bulb and harness as your test light. Typically with a milli volt draw, there is not enough voltage to light the larger test light softtouch mentions, this is not the situation in your case. Using the smaller bulb allows you to have a "test light" with the capability of lighting up when there is only milli volts present.

again, be careful on what you doing, jumpering out,, or injecting power on because frankly, there are too many errors or misleading documention in the EVTMS and shop manuals for the unique TC with buttstuffog clusters.

The 3g alt cheet sheet we have a sticky on should be accurate "as far as we know" but i still wait for someone with a TC to chime in and comment, hopefully our 3g instructions posted are not directly effecting your car in some way.

Alternator wires?

Reply #17 – July 31, 2011, 12:41:50 PM

Tom, do you know what size the shuts are engineered to?
Long ago, I asked the other "Tom" ~turbocoupe50~who pretty much knows everything about anything like softouch and he wasnt sure.

Alternator wires?

Reply #18 – July 31, 2011, 03:15:25 PM

With all the wires off the starter solinoid including 12 volt bat I still have a draw?

Alternator wires?

Reply #19 – July 31, 2011, 03:42:39 PM

Do you have the test light between the neg battery cable and the neg battery post?

Alternator wires?

Reply #20 – July 31, 2011, 04:00:58 PM

How are you testing for a draw?
Your troubling shooting proceedure may be leading you down the garden path.

Alternator wires?

Reply #21 – July 31, 2011, 04:22:25 PM

Not now I'm on the positive with a volt meter in line with the post and terminal. I'm pulling 6.5 amps with the key off. Already replaced the fuse in my meter the other day.

Alternator wires?

Reply #22 – July 31, 2011, 04:59:05 PM

Quote from: thewestie;364394

Not now I'm on the positive with a volt meter in line with the post and terminal. I'm pulling 6.5 amps with the key off. Already replaced the fuse in my meter the other day.

If you have the battery cable disconnected from the battery and have a volt meter between the battery post and the disconnected cable, you should see 12v battery voltage.
You are not measuring drain.
Your meter "sees" the negative side of the battery on the disconnected positive cable through what ever loads are turned on in the car. Some of the loads cannot be turned off, like the radio, clock and computer keep alive and the alternator.

You see the voltage but are not drawing any current with the cable disconnected.

The DC electronics rule is when you have an open circuit ( taking the battery cable off opened the circuit) the entire applied voltage will be seen across the open.

The 6.5 amps you read with your amp meter says you have a heavy enough drain to light the test light. That is the way I recommend trouble shooting it.

Alternator wires?

Reply #23 – July 31, 2011, 05:23:35 PM

I've walked away for now. I can see why projects get put on hold or sed.

Alternator wires?

Reply #24 – July 31, 2011, 06:22:02 PM

Sorry if I made it sound complicated.
With the test light you don't have to worry about blowing the fuse in your ammeter.

Alternator wires?

Reply #25 – July 31, 2011, 07:57:40 PM

OK he has a heavy draw down at 6+ amps. Something is ON. The SHUNT is as i remember 25 MILLI amps. That makes no difference because the ammeter in the car is actually a MICRO VOLT METER that reads the voltage drop across the shunt and is converted to amps. The shunt is irrelevant. You have to keep on disconnecting circuits till you find the DRAW. The best way is with a test light and then a meter after the trouble is cleared. Install the test light in series with the Negative battery cable

Alternator wires?

Reply #26 – August 01, 2011, 01:18:28 AM

you may have meant something different than what you typed in post 19, but,
If i assume I think and know what you meant to say,
then replace your starter relay and put this puppy to rest.
With all the "small ring lug wiring" unhooked and the battery cable still connected, its the only device remaining. ITs probably the only thing in the car that can put up with that much continuous load and not smoke check itself.

tom
The shunt topic was a side line discussion because its on my list of things to do on a circuit I am documenting. However,, Im not sure the meter can be a uVolt meter, makes no sense. mVolt yes, but if its reading micro volts, then thats one heck of a calibrated buttstuffog meter. Besides, they dont engineer shuts to milli amps,, they are engineered to Xvolts, maybe you meant 25milli volts, can you confirm your source?
For example, I know of 2LB to 40LB shunts that are 100A to 10,000A and 50mv rated.

Alternator wires?

Reply #27 – August 01, 2011, 01:31:34 AM

Quote from: thewestie;364394

Already replaced the fuse in my meter the other day.

well, i should have warned you sooner than what I did, been off the board for the a long while.

I would never check for amps on anything until i was dead sure it was a small amount of current by educated process of elimination.

Alternator wires?

Reply #28 – August 01, 2011, 06:24:22 AM

I stand corrected i meant MILLI VOLT METER. NOT MILLI AMPS.

The way i understand it is the shunt which is designed into EVERY AMMETER.The milli voltmeter READS THE VOLTAGE DROP ACROSS A GIVEN SHUNT. THE VOLTAGE LOSS OR DROP IS IN Milli volts. Thats what the meter reads and it is calibrated in AMPS of course. Its been a while since i took my electronics courses. I messed up the nomenclature SORRY. How about VERY VERY SMALL VOLTAGES HA HA HA Sorry. Thanks for pointing that out. I am getting old.

Alternator wires?

Reply #29 – August 01, 2011, 11:40:10 AM

Jcassity I should of mentioned the battery is in the trunk and a dedicated wire to the alt has been run. Ive been presented with the opportunity to try a brand new not rebuilt ford alternator and see if I still have a draw. I have to wait till Wednesday though