[JVunk]

I am Having a problem with My 83 Mustang draining the battery over night. I believe it is the Regulator. I was wondering if there is a way to test the regulator with a multimeter so that I don't replace the wrong part. The voltmeter in the dash shows 14 when at 2000 rpm but only 12 at idle and two days ago on the way to work my Gage was showing 16. which leads me to the regulator but want to be sure. I have been disconnecting the negatives when I get to work and when I get home since Monday. It is getting old. Thanks in advance.

[FOHLDMON]

if you have a multi meter put it on d/c voltage and check youre battery voltage @ idle and @2000rpm's.it should be 13.5 volts or more (no more than 14.6volts unless there are problems with the system)for corect charging if you think that the regulator the put youre meter on d/c amps and un hook the negative battery hook the hot leg to the negative battery post and negative leg to the negative battery cable and check the amp draw.be aware that a perasidic drain on the system may be caused by other things to try to stay on like air bags-ecm's-pcm's-and bodycontrol modules by this i mean check it quick when you take it off (the negative battery cable),then record youre results,but again be careful not to exceed youre meters amp ramge,most are 10 amps.shut off all unused elec. draws on the system before this test also.after recording youre results then remove the leedss frome the altinator and recheck(caution the leeds to the altinator are hot and sould be taped well with elec. tape).if the ampdraw drops the altinator is probly the cause.if no change then one at a time pull a fuse and recheck the amp draw.when it goes away check those wires/componets and it will probly leed you to youre draw.hope this helpstommy

[KULTULZ]

Our friend full-fielding

Then you can try full-fielding, which is actually a process of elimination: If the system puts out with the regulator bypassed, then the alternator is obviously capable of doing its job. There are various ways of doing this depending on the design -- you know, grounding the little tab in the back of a Delcotron SI with a screwdriver, jumping a typical Mopar's field terminal (look for the green wire) to ground, connecting the BAT and FLD terminals of a garden-variety Ford, etc. Just keep in mind that the idea is to complete the field circuit. If the alternator wasn't producing current, but does now as indicated by a rise in voltage at the battery, you can be sure the regulator is at fault. If there's still no charging, the alternator is the culprit.

Excerpt From- -CHARGING SYSTEM MAINTENANCE-

[JVunk]

I checked the draw with my multi meter on the ten amp setting and did not come up with anything. And I left it hooked up and it was still fully charged this morning but on the way to work it was putting out 16 - 18 volts at 2000 rpm and 14 at idle according to my voltmeter in the dash so I am going to replace the Regulator. Hopefully that will take care of it. I don't know why suddenly the draw came and went like that. I will have to start checking all of the connections. Thanks for the help guys

[docvette]

Doc here,

I'm not a Ford guy at all..Is the 83 an external solid state regulator? or is it internally regulated ?

If you got NO draw at all, on a modern computerized Vehicle something is a~miss..normal is 0.6 to 0.8..with computer and CD Presets..Maybe recheck your meter? Scale?...

Do a Voltage test across the battery on DCV, V X 50 or autorange, with it running, and compare against your dash unit for accuracy..It may be the gauge is out of calibration.

Also, when doing an AMP check, In SERIES with the cable, don't forget to reduce the scale until it is at the lowest scale the readout can handle...

It could just be possible to that something "stuck" on like a glove or hood lamp on that one occasion , although the high voltage readings make me suspicious.

Doc