Help with parasitic draw

Okay,
I have a 79 Fairmont 200 in a 66 Mustang.
Was having trouble with battery drain.
Did a parasitic draw test with my multimeter.
Disconnected the negative from the battery. Checked for amps running from the negative pole to the loose cable.
I’m getting a 1.71 amp drain.

I did the fuse test. Pulled out each fuse one at a time. No change in drain. 1.71 amps. Note 1.) I pulled each out individually, checked for a change in amp drain and returned the fuse. Then moved on to the next and so on. Note 2.) my car doesn’t have a fuse in the cigarette lighter slot.

I also read that it could be the alternator and to test this by removing the largest wire from the back of the alternator. I did this and still got a 1.71 amps drain.

Help, where do I look next.

Any help is greatly appreciated. Thanks.

a ground has gone bad?
50 yrs of rust...

a 'positive' wire is touching the body/frame?
(ele is the aspect of auto systems I know the least, sorry :nono: )

could it B w/in a component?

Unfortuantly U just gotta start @ one end & wrk ur the way thru to the other end.
Isolate specific harnesses, check each out 1 by 1. Try the most likely earlier in the search. (I'd say rear harness where the water gets, stays, is not seen. AND the engine compartment). But again, not my forte`.

Good luck there's more experienced who'll B along shortly - that may get U started?

Alternator's relay, horn relay, brake light switch, ignistion switch, headlite switch, heater motor & switch, windshield wiper motor and switch, dash gauges voltage regulator (should read about 6 to 8 volts. Check coil wires for voltage load off and with the ignistion switch in run position it should read 7 to 8 bolts, in start pistion should read 12 + volts. By the way you can get your starter, alternator, and the alternators regulator tested free at many auto parts stores like NAPA. Good luck

Bubba,
Forgive the dumb question. When testing the various switches, relays, etc,..., do I just do like the fuse tests and just unplug them and check to see if the amp drain drops to normal?
Thanks,
Harlon

Yes for sure compleatly unplug them until you find which is causeing your load or you can see if you can read any voltage with the the ignistion switch off. Sometimes these old relays and switches can stick. One other thing I missed above is the DSII's wiring system the ICM has a Red & White wire the Red wire should not read any voltage with ignition switch off and 12 + volts with ignition switch in the run position. Good luck in the hunt.

On the plus side of the starter solenoid, remove the wire that supplies the juice to all the factory wiring.
Check your readings?
It maybe an internal drain within the battery, via shorted plate of plates.
Good chance it is a faulty diode in the alternator.
Like Bubba stated, disconnect one relay at a time, horn, voltage regulator & any relay that have been added.
Need to see if the draw is on the engine side or past the firewall to the interior.

Fairly certain I narrowed it down to the voltage regulator.

Disconnected the three wire connector that runs from the back of the alternator. Reading - 0.00 amps.
Plugged it back in - 1.71 amps.

Followed this line through the bottom of the radiator support over and up to the voltage regulator. Pulled the plug on the regulator. Reading - 0.00 amps.

So I’m thinking I have a bad voltage regulator.

Glad your getting it narrowed down Harlon, I would still take that Alternor in to be tested too, as they are often the real cause. Good luck

Thanks,
This may help clarify a path forward for my son and I on this project. At least a start.

We still need to run a compression test to verify that the engine is remotely healthy. Hopefully we’ll get that done tomorrow.

Part of the long term plan has been a full rewire. The American Autowire harness we were planning on using requires using a one wire alternator. I think I’m going to look into starting that process with one of the one wire alternators with an integrated regulator.

Ford 3G alternator can be wired as a 1 wire alternator. And it's a direct bolt in replacement if you get the right one.

Hi, if you decide to change the voltage regulator I would switch to the newer electronic regulator. They seem to last forever. I also do fine with the 60 amp replacement alternator. Good luck

Had same problem .... check the horn ring as it was shorting out on the steering wheel (both original horns were bad and not working).

Harlon":3id0s79z said:

Thanks,
This may help clarify a path forward for my son and I on this project. At least a start.

We still need to run a compression test to verify that the engine is remotely healthy. Hopefully we’ll get that done tomorrow.

Part of the long term plan has been a full rewire. The American Autowire harness we were planning on using requires using a one wire alternator. I think I’m going to look into starting that process with one of the one wire alternators with an integrated regulator.

Click to expand...

Congrats Once you get your alternator / charging system working along with a fully charged battery, then it probably will run much better. The electronic ignition DSII needs to have enough voltage to work properly. Good luck on your repairs

When I was searching for the source of our parasitic draw there were two disturbing things I noticed.

1) Corrosion. When I pulled most of the wires for the coil, distributor and module the leads were coated in white corrosion. On the module plugs it had grown out from the connectors and surrounded the leads a 1/4 inch or so. When I pulled the center plug on the distributor it fell out of the wire plug end like white dirt.

Is this typical? Or is this an indicator of something that needs addressed before I install new wires, plugs, module, etc,...,?

2) Dry rot. No real question here, I was just surprised that many of the old plastic locking connectors just fell apart when I disconnected them.

Thanks

With wires the main thing is the condition of the wire itself. If the wire and its insulation are good, intact and flexible w/o cracking within reach of their terminus, just replace the terminal. Otherwise replace the wire back to at least where it is good or serviceable and safe.

Harlon":378tv54n said:

When I was searching for the source of our parasitic draw there were two disturbing things I noticed.

1) Corrosion. When I pulled most of the wires for the coil, distributor and module the leads were coated in white corrosion. On the module plugs it had grown out from the connectors and surrounded the leads a 1/4 inch or so. When I pulled the center plug on the distributor it fell out of the wire plug end like white dirt.

Is this typical? Or is this an indicator of something that needs addressed before I install new wires, plugs, module, etc,...,?

2) Dry rot. No real question here, I was just surprised that many of the old plastic locking connectors just fell apart when I disconnected them.

Thanks

Click to expand...

It's probally not corrosion. All the DuraSpark II ignistion conections used an electrical grease (Ford orginally used a white grease on these plugs like No Ox) this protects the wiring conections from corrosion. Yes many times the plastic electrical plug connectors become brittle with heat and also with age. Good luck edited

The name of the grease for electrical connections is"DiElectric"grease and it is almost clear(About the color of Vaseline).Use it on all electrical connections GENEROUSLY.On battery cables and posts too.Works really good.Can be purchased at any electrical supply house or Radio Shack or auto parts shop of your choice.Comes in one use packets up to IIRC 2 pound cans.
Good luck.Have fun.Be safe.
Leo

the 'white corrosion' is powdery & frm age. It too is another draw, so dust off (w/lill wire brush) & coat w/this grease as Leo sez or it takes the H2O outta the air & has this 'powder' on it. Don't use much cuz it attracks dust...

Many, when assembling, after a crimp @ connectors, slide up a pre-fitted shrink tube, heat 2 shrink & say "Well done". Others say corrosion hides under there. I disagree. I think it protects...

Don't get demoralized w/the search. Some of the guys laid it out pretty well above. I tie off the wire w/a bit of string around it to indicate I've finished that 'area'. I have a wire brush & a grinder near to make new grounds, a box of assorted connectors, solder, paste, gun...anything needed on a hunka plywood to scoot around w/me as I go. Once done (w/the lill, easy maintenance but time consuming attention) you can congratulate ur self and know there's no need (if done as U go along, ck, make better) for this labor intense wrk for another 20 or so yrs...