Sorry that I didn't see your reply last night.
I mentioned GM for a reason. Chrysler has been the world's leader in innovations that benefit car owners since at least the 1950s. They developed the "AC generator" for 1960 models, then other manufacturers copied it years later. The term "alternator" is copyrighted by Chrysler. They were first with the electronic voltage regulator, electronic ignition, computer-controlled ignition timing, lock-up torque converter, air bags, even anti-lock brakes in 1969. Many people list them as the third best in the world for customer-friendly business practices.
GM has been the leader for decades in coming up with business practices that benefit GM at the huge expense to their unsuspecting customers. That includes computer modules that have to be purchased new from the dealer, then programmed to that specific vehicle, unavailability of radio service manuals so you're tied to their two grossly over-priced repair centers, and numerous other things that require owners to go back to the dealer. They had a huge problem in the late '80s and early '90s with all kinds of various problems that were solved by replacing the Engine Computers, over and over. Because of that, older mechanics jump on the computer as the first and only suspect for every problem on every car model. That isn't the case. Ford and Chrysler had almost no computer failures. In fact, I'm sitting in my '88 Grand Caravan daily driver right now. It still has the original Engine Computer and it's working perfectly. We had a stretch for about ten years where no one had a big rash of failures, but now that circuits are getting so ridiculously complicated, we're seeing more failures.
The engineers at GM redesigned their generators for the '87 model year and went from one of the world's best designs to by far the worst, and they seem to have no desire to improve it. Most manufacturers design upgrades all the time to make their products more reliable, but I guess selling more replacement parts is more important than customer satisfaction.
You asked about programming the ignition switch, and that's why I mentioned that it's a GM trick to get owners back to the dealership.
Anyway, let me get down from my soapbox and see if we can solve your problem. The burned solenoid contacts was a real big problem with the Nippendenso starters used on Chryslers, Hondas, and Toyotas. It was an easy and inexpensive fix, but you had to know about it and where to find the parts. Most people just replaced the entire starter, but if you got one from a salvage yard, you had a good chance of having the same problem in a year or two.
The first thing in your favor is you don't have a Nippendenso starter. Yours uses a standard solenoid bolted to the starter motor, and I haven't heard of any common problems. The second thing is you replaced the starter already, and the chance of having two bad ones is pretty unlikely. That's assuming you installed a rebuilt starter and not a used one. That just leaves the cables and connections, and if I'm right, we'll find it with the voltmeter.
We could measure "voltage drops", but in this case it will be just as easy to simply measure the voltages at various points. The hardest part of this test is going to be catching the problem while it's occurring, and to keep it in the bad state so it can be diagnosed. You may want to wait until the problem acts up more often. One way to start is with a helper turning the ignition switch. The problem is the engine is going to want to start, and if you cycle the switch fast enough, many of the models will only let you do that three times before you have to wait a while. A better trick is to pop the cover off the starter relay and squeeze the contact, or you can remove the relay completely and use a jumper wire or stretched-out cotter pin to jump terminals 30 and 87 together. The advantage to the cotter pin is if you can catch it acting up, you can leave that in place, then do the testing without a helper. You can also do the following procedure when the starter is working properly, but it's irrelevant because the engine is going to start right away, and the readings will have little meaning. It will give you a feel for doing the procedure though.
Once you have the problem occurring, starter solenoid engaged, but the starter isn't cranking the engine, place the voltmeter probes right on the battery posts, (not the cable clamps attached to them. For this example, lets say you find 12.0 volts. Now move the positive probe from the post to the cable clamp, then move the negative probe to that clamp. You should still read 12.0 volts. When the starter is cranking the engine, you're allowed 0.2 volts less at each clamp, actually, each mechanical connection, but that is next to impossible to measure this way.
Assuming you still have 12.0 volts, move the negative probe to the next accessible test point which would be the metal terminal that's bolted to the engine block. If you find considerably less than 12.0 volts, that cable has a problem. If you still have 12.0 volts, move the probe to a paint-free surface on the engine block. If you still have 12.0 volts, the negative half of the circuit is okay.
Now move the positive probe to its next accessible test point which is the terminal on the end of the cable bolted to the starter. If that has 12.0 volts, move the probe to the copper stud that terminal is bolted to. If you find a lower voltage there, that connection needs to be cleaned and tightened.
The next test point is the other side of the solenoid contacts. That's going to be either a braided bare cable or a metal strap bolted to the solenoid. If you find less than 12.0 volts there, the contacts are arced and the solenoid or entire needs to be replaced.
You might be able to save yourself some time by going right to the copper stud on the starter. If you have 12.0 volts there, you didn't need to check every test point in between.
You're looking for the first place you find appreciably lower voltage, but it's important to remember that these readings are only valid when current is supposed to be flowing, meaning the starter is engaged. When the starter is turned off, and no current is trying to flow, you WILL find full battery voltage at all the test points up to the starter's stud, even if there is a poor connection in between, (as long as the circuit isn't broken completely). If it helps, think of standing on a garden hose. The restriction caused by your foot is equivalent to the restriction to current flow caused by a loose or dirty connection. If you start with 50 pounds of pressure at the faucet, you'll have 50 pounds of pressure at the hose nozzle when it's closed, and no water is trying to flow. As soon as you open the nozzle and water tries to flow, you'll have no or very low pressure after your foot. That equates to no or low voltage after the bad connection.
A different approach is to connect a test light, typically to the copper stud on the starter, and to the battery POSITIVE clamp with clip leads so you don't have to hold onto it. Run the wires inside the vehicle, or clip the light under a wiper blade where you can see it. This test works great when the problem acts up very seldom. Since both probes are in the positive half of the circuit, the test light will not light up during cranking OR when you're not cranking, as long as there's no bad connection. If the cranking problem occurs and you see the test light light up at the same time, there's a bad connection between the two points where the light is attached. Here you're measuring a voltage drop. That's the difference in voltage between two points in the same circuit vs. Measuring the voltage AT a point in relation to a common point, meaning ground.
Sunday, August 24th, 2014 AT 10:38 PM