Alt/Regulator question please

[Dne']

Hi,

Taking in consideration of checking amp draw with door closed, all switches off, like Midlife instructed, there is no amp draw with the key off. That being said, the VR is mounted and plugged into the new harness, and the Alt is also wired and connected to the battery. With the igntion in the ON position, I noticed a faint smell(more like a faint paint smell) and quickly disconnected the battery. The VR was warm to touch, not hot. I noticed a faint boing sound coming from the vr when connecting the battery just for a second. Another thing, the metal of the alternator is kind of warm, and the rest of motor is stone cold.

The plug going to the altnerator is unplugged now. With the key in the on postion, the push on connector itself is hot which goes to the ignition on the s solenoid. Is that correct, I thought it should be the ignition terminal itself that would be hot with the key on.

The two center female connectors inside this push on plug assembly are hot with the key on.

Just included this photo of the alternator making sure the wires are in the correct place.
Any help is appreciated!

I'm going to spend the next hour looking for my shop manual!

 

[Midlife]

With key to ACC position, nothing should be hot except the battery/solenoid lines, some of which go to the VR. This is the same condition as the key OFF or out of the system. This position only energizes circuitry inside the passenger compartment.

with key to ON position, in addition to ACC position, the rearward slip-on pin on the solenoid will be hot once you put the 90* connector on it. That signal is not an input to the starter solenoid, however. The coil should now also be hot (9V).

With key to CRANK, the forward 90* connector is now hot and energizes the starter solenoid. That puts current from the battery to the rear large starter wire to turn over the starter, and also sends 12V out the rearward 90* slipon connector. From there, that line is connected to the coil through the firewall connector, so the coil now reads a full 12V instead of 9V.

From your discussion, your starter solenoid may be bad. But first, with key in ACC and everything shut off, do you have any current draw as you measure between the negative battery post and the negative cable (disconnected from the batrtery, of course)?

 

[Dne']

THank you Midlife!
Do you have any suggestions for a decent home meter to measure amps, volts/ohms~ I have a little squirrely meter that I don't trust? I have Grainger down the street that I'm sure carries a stockpile of meters. Just like to add a nice meter to my tool collection. I'll be going there in a little bit to see what they have.

meanwhile~
I didn't try anything with the key to the ACC position. I just turned it to the ON position. I'll try again later. (Gary(hubby) wants to head to the lake this afternoon). Back to working on the '57.
Regarding the rearward slip-on pin of the starter solenoid(SS)? Internally of the SS, does it connect somewhere inside of it? or is the pin just fixated on it as just a connecting point? So it's the 90* itself that is hot. I'm discombobulated about that pin on the SS!

The starter does engage and turn the motor with the key turned to the 90* start~ just trying to get the electrical done so when Herb(my motor man) comes over to help me start the stang, All will be ok!

My main concern was the VR becoming really warm with the key in the ON position and alternator(not as warm,but noticeably not cold) too. I don't know what prompted me to even touch the alternator to find this out, but it should have been stone cold like the surrounding metal, yes?
**I promise to find my shop manual and find the schematic of this today even if I have to buy another manual!


****************************************************************
(MIDLIFE)
with key to ON position, in addition to ACC position, the rearward slip-on pin on the solenoid will be hot once you put the 90* connector on it. That signal is not an input to the starter solenoid, however. The coil should now also be hot (9V).

With key to CRANK, the forward 90* connector is now hot and energizes the starter solenoid. That puts current from the battery to the rear large starter wire to turn over the starter, and also sends 12V out the rearward 90* slipon connector. From there, that line is connected to the coil through the firewall connector, so the coil now reads a full 12V instead of 9V.

From your discussion, your starter solenoid may be bad. But first, with key in ACC and everything shut off, do you have any current draw as you measure between the negative battery post and the negative cable (disconnected from the batrtery, of course)?
[/quote]

 

[Midlife]

The only thing that happens to the rear-ward 90* connector on the starter solenoid is when the key is turned to CRANK. At that time, the solenoid SENDS 12V to the ignition coil as the starter is turning. Why? The starter, when turning, can lower the voltage some, and with the addition of the resistor wire, can cause the voltage at the coil to be so low that the engine can't catch. So...the solenoid allows a path to the coil bypassing the resistor wire.

The VR may be hot because it also is a relay, and for early Mustangs (64.5-68), it is always energized. The contacts may have become fused, allowing signals sent to the alternator that it shouldn't be. My suggestion is to replace the VR (it's cheap!) as one of your early trouble-shooting steps.

For reasonable digital volt-ohm meters, Sears sells one that isn't too bad. You want one that can measure up to 10 (preferably 20) amps DC, and down to milli-amps DC. Grainger should probably carry something along that line. This one may work: http://www.grainger.com/Grainger/items/2AVA1?Pid=search

 

[Dne']

Thank you for the Great explanations! I even understood what you wrote!

I'm going to get that meter from Grainger, seemed like a good price too!

Probably be Saturday before I get to do any more to my stang~ I just hope I left my shop manual at our lakehome! I hate to buy another one! lol

Thank again Midlife, I'll keep you posted!
dne'

 

[Dne']

Electronics 1101?

Midlife, could you educate me a little bit on my new instrument? I just put the meter on what I think is correct, and never get a reading that makes any sense to me. Right now I'd just like to measure DC amp draw from the neg battery post to the battery terminal ground. I just bought this meter and it came with some vague instructions, however I could just use a little electronics 1101! Maybe it would be beneficial to have a thread directed to basic stuff on our stangs and directed by the guru of electrical~ you!
Any help is appreciated!

 

[Midlife]

OK! How to use a DVM! The most useful portions are the resistance meter (upside down "U", or the greek omega symbol). The black lead goes to the ground (center), and the red lead goes into the right hole. You measure resistance across something (say like a wire, a resistor, etc.). If there is no resistance, the meter should read less than 1 ohm. This indicates that there is continuity between where you have placed the two leads. If one of the leads is on the power side (say of a light) and the other is on the ground and you have no resistance, that means that the power side is also grounded. In this case, you'll have all available power from the battery going through that wire to ground: the wire can't handle it and very quickly will get very hot, smoke, and can start a fire. Usually, resistance for a true feature (e.g. lamp, gauge, etc.) will be in the range of 5 to 100 ohms. If you don't have a bulb in the lamp, however, you'll see infinite resistance, and there is no path for the poor electrons to follow.

The other useful thing is the amperage. This meter measures current up to 10 amps, 300 milliamps, and 300 microamps. The two most useful settings will be the 10 amps and 300 milliamps. For the 300 mamps setting, leave the lead imputs as shown in the photo. In this case, you're going to put the leads between the two connectors so that the current runs through the meter. For the 10 amp reading, you'll need to switch the red input lead on the left-hand side. I always recommend testing current at the highest reading: it will tell you whether you have current greater than or less than 300 milliamps. If less, you'll get a more accurate reading switching to the other setting. If you try and measure 5 amps through the 300 mamp setting, you'll blow a fuse, and the meter will read zero current, and you'll think everything is great, but it isn't!

The third most useful measurement is VDC or volts direct current. Everything on a Mustang is DC current. In this case, set the black lead against a grounding point (e.g. chassis) and the red lead against something that should be hot: a fuse, a bulb input wire, etc. With the battery connected, you should see a hair over 12V with the engine not running. With the engine running, you probably will see anywhere from 13.8 to 14.5 volts. Putting the black lead on the negative battery post and the red lead on the positive battery post allows you to see what the voltage is on the battery. Start the car, and check out what your voltage is! Now place the red lead on the coil input line: you probably will see 9V.

Does this help?

 

[Dne']

THank you MIdlife!!

Whoo hoo! much better than the instructions that came with the meter! I'll print your explanation and keep it with my meter! Thank you for the excellent instructions Midlife! I believe Radio Shack has some simple electronic learning "toys"~ I may look into that too. I believe anyone can put the stang together, but when it comes to the electrical portion, can stop one in their tracks! lol I won't get to apply this until Sunday, we're at out lakehome, but maybe I can experiment on my '57 chevy a little.
Again! Thank you!!!
dne'