'83 D150 overcharge
- Thread starter mwd782
- Start date
-
Mattax
Just the facts, ma'am
Then 1 . is open, no connection.
Mattax
Just the facts, ma'am
If touching both terminals resulted in an open, then the alternator can not work. We know the alternator does work. Make sure you have good contact, and if need be rotate the pulley asliughtly. The carbon brushes add resistance but not 200 ohms worth.
Then check each to ground. if they still show open, then they are not grounding internally.
Then check each to ground. if they still show open, then they are not grounding internally.
Mattax
Just the facts, ma'am
Read this and you can see what's inside the magic box that could be broken.
Identifying Chrysler Alternators (1960-1976)
Roundback and Squareback refer to the style of housing. Roundback through model year 1969. Roundback for model years 1970-71 usually has a slightly different rear housing Squareback Revised Squareback Is most easily differentiated by the thin middle between the housings. Overall these...
www.forabodiesonly.com
However since the alternator was producing power, I suspect the measuring was faulty
Does not look like the meter is working. That is a stupid display I guess they are trying to say "I" as in "Infinity" or "open." But it looks like it is saying 1 something ohms. Anyhow the meter may be defective or one probe open. Try the other resistance settings.
Make CERTAIN your probes are held hard together. If that does not work, remove either probe from the meter, and take the remaining connected on and touch it into the vacant connector. Then remove that probe from the meter and try the other lead
The main thing we are trying to find out, is whether the rotor or either brush holder is shorted to the case. Again, you should have continuity BETWEEN the two brush terminals, but open from either to the case.
4spdragtop
Well-Known Member
Wiring....
Mattax
Just the facts, ma'am
Why are you measuring a VR?
First establish how the meter works.
If touching the probes together is zero, then no touching 1 . that should be infinity.
Next if you want to test a known or somewhat known, measure the resistance of each resistor.
Now go back to the alternator. Is either terminal shorting to the housing? Does the meter reads infinity?
Then check for continuity between the the two terminals.
Mattax
Just the facts, ma'am
Based on this I'd start with the 2000 Ohm range and see what it shows.
Maybe the 200 ohm range is dead.
GAR_TL_077.pdf
When testing the dual ballast resistors, one should be around 5 ohms and the other 0.5 ohms. But at some point the 0.5 ohms was changed. Your shop manual will say what it should be in '85.
Maybe the 200 ohm range is dead.
GAR_TL_077.pdf
When testing the dual ballast resistors, one should be around 5 ohms and the other 0.5 ohms. But at some point the 0.5 ohms was changed. Your shop manual will say what it should be in '85.
This is exactly what happens.
With all tests meter reads infinity. No continuity between terminals.
Which probes go where for this test? Key on or off?
Don't be doing random stuff like this. Meters may not be protected, and you NEVER do resistance tests on circuits which MAY have power applied.
Try this. Take your alternator, "rig" a couple of wire leads, either with alligator clips or the push on flag/ spade terminals and connect them to the field terminals. hold one to a good ground, like the block, and touch the other to battery POS. In subdued lighting, you should see a spark. Sometimes you can even HEAR the spark, if your hearing is good.
There is no possible way that alternator can charge at ALL if the field is open. It is a simple electromagnetic coil (electromagnet) connected between the two field / brush terminals.
There is no possible way that alternator can charge at ALL if the field is open. It is a simple electromagnetic coil (electromagnet) connected between the two field / brush terminals.
After doing proper between two points on ballast resistor reads 1.5 on 200 ohms
Definitely no spark.
So I turned the truck on today with the alternator with open field (currently one brush broken) and began to overcharge the battery up to 16+ volts. Unplugged the VR and the same. It only went back to 12.8 v when I unplugged the red wire from the field terminal in the alternator. Is this normal?
-
Similar threads
