Need a electrical guru

[rsd859]

My new alternator isnt charging, replaced the volt reg and ballast resistor. Also my a/c heater blower motor isnt getting power. I pulled it out and tested by hooking it up to the battery.

So I dont even know where to start on the alternator. Im going to pull it out and take it back to oreilly's and have them test it. But if it tests good, then what?

What are the common problems with the blower motor.

Thanks for the input, Rich

 

[WileE]

Start simple. First, check fuses and grounds. Get out your multimeter & wiring diagram, start checking circuits for voltage & resistance. Loose connections, broken/frayed wires, corrosion in bulkhead pins, fuse block, etc, etc. Check the field circuit to the alternator. Electrical may seem confusing, but if you forget about all the other wires & isolate the system circuits you're working on, good chance you'll discover the cause.

 

[62 Dart Convertible]

Hi Mate

Let's forget your blower motor for a minute. That is a secondary problem.

The ballast resistor is in the ignition circuit and has bugger all to do with if your alterrnator is charging.

Alternators are simple devices. The voltage regulator will put a voltage on the field winding inversely proportional to the battery voltage, so in normal running, will put a few volts onto the field winding of the alternator (while the engine is turning of course) that will make your alternator B+ terminal pump out some amps to supply your system and keep the battery charged. Put a voltmeter on the field connection while the engine is running and switch on some electrical load E.G. headlights. If the field voltage at the alternator reads 0V, then your regulation system is not working. It may be a faulty regulator or a break in the regulator to alternator field wiring. If the field voltage is close to 12V then your regulator IS working but I would question the function of the alternator itself. Problem may then be a alternator field winding open circuit.

If you have no idea what I'm talking about, then it may be that I have drank too many beers tonight, or you need some further technical assistance.

I will sober up by the morning, but problem is I won't be as clever then......

Common problems with blower motor circuit are - the motor could be knackered, the switch could be stuffed, the low speed resistor could be pooped or the fuse or wiring could be open circuit. It is up to you (or the next guy) to test each bit and determine which is the offending player. I would start with the fuse and work your way along the circuit till you find the problem... A voltmeter and a circuit diagram is the key.....

 

[rsd859]

Get some rest 62 dart! Im at work and racking my brain about the issue and yes you lost me at field connection. Where is that located? We are working on a 73 Satty/RR

 

[67 coronet]

the field connection is on the alt.normally marked by an f or says field in your wire diagram.on your car there should be 3 hook ups at the alt.larger bolt is battery power.2 small ones are a ground and a field.putting it as simple as possible.prob gonna be a green wire.

 

[rsd859]

Yes there are the 3 connections, the blue and green go to the volt reg right? Do I need to make a ground strap for the volt reg? I just dont understand why it was working fine before I put the new one on. It was making a noise and there were shavings comming out of the old alternator thats why I replaced it.

 

[Pops1967GTX]

TROUBLESHOOTING---BOOK----
This test will determine whether or not the system is charging the battery and, if not, whether the alternator or regulator is at fault. It requires a voltmeter capable of measuring at least 16 volts, down to tenths of a volt.
If the charging system on your car has an externally mounted regulator, warm up the engine before performing the following test:
1. Turn off the engine, lights, and all other accessories.
2. Attach an engine tachometer according to the manufacturer’s instructions.
3. Connect the voltmeter to the battery by attaching the positive lead to the positive terminal and the negative lead to the negative terminal.
4. Note the voltmeter reading. If it is less than 12 volts, charge the battery. Then note the voltage reading again and record it.
5. Start the engine and slowly increase the speed to 1,500 rpm.
6. Note the voltmeter reading again. If it exceeds the engine-off voltage by more than 2 volts, the system has a faulty regulator, a poor regulator ground, or a short circuit in the wiring between the alternator and regulator.
7. If this voltage reading exceeds the engine-off voltage by less than 2 volts, perform a load test.
LOAD TEST
1. Keep the tachometer and voltmeter connected as they were for no-load test.
2.Note and record the voltage reading.
3. Start the engine and turn on the heater (or air conditioner) at high speed. Turn on all lights and accessories.
4.Increase the engine speed to 3,000 rpm and note the voltmeter reading.
5. If this reading exceeds the engine-off voltage by 1/2 volt or more, the charging system is functioning properly.
6. If his reading exceeds the engine-off voltage by less than 1/2 volt, perform a full-field test.
FULL-FIELD TEST
When the regulator’s control function is bypassed, the alternator runs full-field. The method of bypassing the regulator differs, depending on the type of vehicle. For this reason, Step 1 of the full-field test changes from car to car, while the remaining steps are the same for all models.
1C. Chrysler models. Turn of the engine. Locate the green wire connecting the alternator field terminal to the regulator; disconnect this wire from the alternator. Connect a jumper wire from the alternator field terminal to a good ground.
2. Once the regulator has been bypassed, repeat the load test.
3. If the full-field voltage exceeds the engine-off voltage by 1/2 volt or more, the regulator is defective and must be replaced.
4.If the increase in the voltage is less than 1/2 volt, either the alternator or wiring is faulty.
5. Inspect the wiring for signs of wear or heat damage.
6. If the wiring looks good, the alternator is probably the faulty component.


The Quick and Dirty Charging System Test

Remove the (+) FLD wire from the alternator.
Put a temporary jumper wire from the same (+) FLD terminal to the large output post on the alternator (battery +).
Start the car and see if it charges. If it does… good alternator. If not … bad alternator. If it did charge, then the voltage regulator is the problem child.
Turn the ignition key to the on position. Check for power on the small IGN terminal of the regulator. If there is, then see if there is any power on the other voltage regulator post to the alternator. A bad ground on the voltage regulator case is a very common problem. If not then you need to chase down the IGN power issue.






A few links with information....

http://www.classicwinnebagos.com/forum/index.php?topic=3424.0


http://books.google.com/books?id=rt...#v=onepage&q=ballast resistor testing&f=false

 

[rsd859]

Thanks pops! Thats some real good info!!!

 

[snakeoil24]

I need to go visit Australia, these buggers know their cars. I think I might go and taste a few Fosters with them.

 

[rsd859]

Found it! I went to remove the alternator, and saw that the green wire has broke off right at the Connector. Going to get a new connector in the morning and surely that will fix it.

 

[62 Dart Convertible]

I need to go visit Australia, these buggers know their cars. I think I might go and taste a few Fosters with them.

Hey snakeoil, I am an electrical person with a habit of over complicating things! I probably should have written "check the green wire hasn't fallen off the alt." first.
When I last checked, nobody in Australia actually drinks Fosters. That's why we export it. We drink the good stuff like Coopers and James Squire and keep it very quiet.
You are most welcome to venture down under and there is no shortage of us that would enjoy a few frothies with you.

Found it! I went to remove the alternator, and saw that the green wire has broke off right at the Connector. Going to get a new connector in the morning and surely that will fix it.

Glad you found the smoking gun!

I made a classic booboo a few months ago when reconnecting the alternator. I put the green wire on the wrong terminal and smoked my regulator an hour before a cruise. Luckily I was able to fix it!!

 

[WileE]

Found it! I went to remove the alternator, and saw that the green wire has broke off right at the Connector. Going to get a new connector in the morning and surely that will fix it.

:headbang:

 

[rsd859]

Here is the broke wire, which is now fixed and working. Any Ideas on the blower motor?

 

[WileE]

So, you say the blower motors ok when it has voltage ? That means its ok, just not getting the juice. Again, just trace the circuit, whether forward or backward & you'll find where the circuit is broken. Did you check the fuse ? Both sides of the block ? the fan control ?

 

[poly3521]

Check for power into the switch. Power goes from the switch to the rheostat to the blower motor. Check for continuity in the switch, there in the rheostat in the heater box, and of course the wires in between. I hope this helps.

 

[rsd859]

Yes, not getting juice. Havent had time yet to check the fuse. Where is the rheostat located and what does it look like? What is the process for checking continuity in the switch? Gonna have to break it down for me I stay away from electrical like the plague.

 

[poly3521]

I don't remember how the AC cars are, but, the resistor block, gm calls it a rheostat, should be on the top of the heater box near the heater core. I think you can get at it from the glove box. On 71 AC cars, power goes from the fuse block to a control switch, its the big plug end on you heater control switch, should be a black wire with a stripe, this is the blower switch feed. The fuse should be second one up on the left side of the block. Should be able to use a test probe for power on both sides of the fuse. If that's good, check that black wire on the big plug on the switch. If that's good, check the tan wire on that same plug, it goes to the blower switch. Make sure the selector lever in NOT in the OFF position. If that's good, Check the switch, then the resistor block on top of the heater box and the wires in between with a multimeter set to ohms, its the omega sign on the meter. If all that's fine, the wire goes through the bulkhead disconnect wire #4, small connector on the firewall side. There's only 2 and the other goes to the wipers. Sorry its a little lengthy, but i hope it helps.