Factory ammeter
HOW TO FIND this drop? This could be a "wrong path down the wrong road" in this case because of the changing load. You may have to figure out how to add load to maintain the charge rate. Not sure what the easiest way, maybe leave the headlights on, engine off, for 15 minutes, then make tests "quickly" and don't run the engine more than you need to make the test. In other words, you don't want the battery to charge up while you are making measurements. Turn on loads in the car, like lights, heater blower.
So follow the path I laid out. "Clip" one lead of your meter to a point at one end....either the battery end or at the alternator end.........and leave it there until you find the biggest drop
Clip up your meter, start the car, take a reading. Kick the thing up onto the fast idle cam to maintain RPM, or screw in the idle screw, again, so RPM stays at 'low to medium cruise'
Take a second wire hook to the other probe of the meter. It needs to be quite long so you can reach into the passenger compartment. You want to get "as close" as you can to the black charge wire INSIDE the car. One accessable point is the "hot bus" on the fuse panel. Find the "hot" end of the fuses that are "always on." So with key off, probe the fuse panel and find which fuses are "hot." Pull one of them and determine which end of the fuse is hot. Clip your meter probe to that.
So now you the meter clipped to the alternator output, and the "hot" buss in the fuse panel.
Start the engine, make sure it is charging "hard" and the loads are turned on, and take a reading. You are hoping for a very low reading, the lower the better. While it is running/ charging, go out to the engine bay side and WIGGLE the bulkhead connector, see if the reading changes lower or higher.
Diagram out what you measured each point and write that reading down.
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What you just measured is where the alternator output comes into the passenger compartment on the "black wire" side of the alternator. Now you must find out if the ammeter is adding "drop." So we need a connection in the RED wire circuit INSIDE the car BEFORE it goes through the bulkhead connector. This might be more difficult.
See if you can reach up and clip your meter lead onto the RED wire at the ammeter. Do this with battery ground disconnected!!!! If you cannot do that, crawl in and identify the bulkhead connector cavity where the big read ammeter wire connects....on the INSIDE of the passenger compartment. "Back probe" that and run your running/ charging test again. If the reading is the same as before, or maybe, say, only a tenth or two volts more, then you can assume the ammeter connections are OK.
Now move to the engine bay side. "Backprobe" the red wire terminal coming into the engine bay and connecting to the fuse link. As before, start and run the engine, measure that. WIGGLE the bulkhead connector See if the reading changes.
Next, clip to the starter relay "big stud" and check that reading when running, and last RECHECK at the battery. Should not change between these last two readings. If it does, you have a problem between the fuse link and the battery
READ the MAD article, this covers the how and why we have problems. The diagram on that page is a great basic diagram of the main power problem area
Catalog
HOW TO FIND this drop? This could be a "wrong path down the wrong road" in this case because of the changing load. You may have to figure out how to add load to maintain the charge rate. Not sure what the easiest way, maybe leave the headlights on, engine off, for 15 minutes, then make tests "quickly" and don't run the engine more than you need to make the test. In other words, you don't want the battery to charge up while you are making measurements. Turn on loads in the car, like lights, heater blower.
So follow the path I laid out. "Clip" one lead of your meter to a point at one end....either the battery end or at the alternator end.........and leave it there until you find the biggest drop
Clip up your meter, start the car, take a reading. Kick the thing up onto the fast idle cam to maintain RPM, or screw in the idle screw, again, so RPM stays at 'low to medium cruise'
Take a second wire hook to the other probe of the meter. It needs to be quite long so you can reach into the passenger compartment. You want to get "as close" as you can to the black charge wire INSIDE the car. One accessable point is the "hot bus" on the fuse panel. Find the "hot" end of the fuses that are "always on." So with key off, probe the fuse panel and find which fuses are "hot." Pull one of them and determine which end of the fuse is hot. Clip your meter probe to that.
So now you the meter clipped to the alternator output, and the "hot" buss in the fuse panel.
Start the engine, make sure it is charging "hard" and the loads are turned on, and take a reading. You are hoping for a very low reading, the lower the better. While it is running/ charging, go out to the engine bay side and WIGGLE the bulkhead connector, see if the reading changes lower or higher.
Diagram out what you measured each point and write that reading down.
==================================
What you just measured is where the alternator output comes into the passenger compartment on the "black wire" side of the alternator. Now you must find out if the ammeter is adding "drop." So we need a connection in the RED wire circuit INSIDE the car BEFORE it goes through the bulkhead connector. This might be more difficult.
See if you can reach up and clip your meter lead onto the RED wire at the ammeter. Do this with battery ground disconnected!!!! If you cannot do that, crawl in and identify the bulkhead connector cavity where the big read ammeter wire connects....on the INSIDE of the passenger compartment. "Back probe" that and run your running/ charging test again. If the reading is the same as before, or maybe, say, only a tenth or two volts more, then you can assume the ammeter connections are OK.
Now move to the engine bay side. "Backprobe" the red wire terminal coming into the engine bay and connecting to the fuse link. As before, start and run the engine, measure that. WIGGLE the bulkhead connector See if the reading changes.
Next, clip to the starter relay "big stud" and check that reading when running, and last RECHECK at the battery. Should not change between these last two readings. If it does, you have a problem between the fuse link and the battery
READ the MAD article, this covers the how and why we have problems. The diagram on that page is a great basic diagram of the main power problem area
Catalog