Acclaim that has the engine light on and the voltage gauge has moved a bit

Use an inexpensive digital voltmeter to measure battery voltage while the engine is running. It must be between 13.75 and 14.75 volts. Holler back with your findings.

Nope. When the light turns on there will be at least one diagnostic fault code in the Engine Computer's memory. It will get you to the circuit or system with the problem, not necessarily the defective part. Many auto parts stores will read those codes for you for free, but only Chrysler makes it real easy to do yourself. Turn the ignition switch from "off" to "run" three times within five seconds without ever cranking the engine. Leave it in the run position. After a few seconds the Check Engine light will flash out the two-digit codes. It will likely start with a single short flash, a pause, then two flashes and a longer pause before the next code starts. That's code 12 which can be disregarded. The last one will be code 55 which just means "end of message" It's the codes in the middle that are important. Record those then holler back.

Too old to be tested? Do they think everyone threw out their test equipment because they hung a new calendar on the wall? You need to find a different mechanic. I drive an '88 Grand Caravan so I know I'll get home again. When the Check Engine light turns on, it means the stored fault code is related to something that could have an adverse effect on tail pipe emissions. There are other codes that do not trigger the Check Engine light. Almost all Chryslers use a gauge on the dash for the charging system. For those that also have a battery warning light, it is just to get your attention since most people don't watch the gauges very closely. The battery light actually has nothing to do with the condition of the battery. It refers to the alternator recharging the battery after starting the engine and while driving. The voltage regulator, which runs the alternator, is built into the Engine Computer where it can be monitored. On some models when a problem is detected with the alternator, the Engine Computer turns the Check Engine light on because low system voltage, (as the battery runs down while driving), can affect sensor readings and the injectors' ability to open fully. The fuel pump will slow down too. You might be able to drive that way for an hour or so with a really good battery, but that hour should be used to get home or to a repair shop. Rather than waste a lot of time worrying about the Check Engine light right now, lets start with the charging system. If both warning lights came on at the same time, there's a real good chance this is going to be a fairly inexpensive repair. Hey, it's an older Chrysler! (I love these cars). Start by grabbing an inexpensive digital voltmeter. Since the engine starts and runs, we can skip over half of the tests and go right to the back of the alternator. There are three wires on it. You should find full battery voltage on the fat black output wire all the time. That's the one that's bolted to the back. For the other two, there are two small metal tabs coming out of the black plastic block that's bolted on the back. Measure the voltages on those two small nuts on the two tabs, but you MUST measure those with the engine running. One of them will have full battery voltage. The other one is the secret. It is supposed to have less voltage but not 0 volts. If you find 0 volts, the diagnosis is done and I'll post a photo of the repair part. On some engines you can do the repair without removing the alternator from the engine.

In nine years of teaching automotive at a community college, two of my best students were girls, ... Well, ... I'm betting they still are! Muffler isn't related. As for the flashing Check Engine light, you have to count the flashes as I described. It's a series of two-digit codes that are related to the problem. Did you measure the battery voltage? Do you have a digital voltmeter and know how to use it? A test light will work too in this case.

There's blinks and pauses between the blinks. Those blinks are the codes being flashed out. If you think you miscounted, some older cars would repeat the sequence over and over until you turned the ignition switch off, but I think on yours all you have to do is wait for the light to stop flashing, then turn the ignition switch off once and back on and it will repeat the codes. Most cars start with code 12. That is one flash of the light, a short pause, then two flashes. Right after that there will be a much longer pause, then the next code will flash the same way. Count the number of flashes. That's the first digit. After a short pause, count the number of flashes again. That's the second digit of the second code if there is one. There can be many codes but it's more common to find no more than three or four. The last code will always be five flashes, a short pause, then five more flashes. That's code 55 and just means it's done.

See if this helps. The light is on when the pulses go up. The first two digits are code 12. There's a short pause between them. I just used code 23 as an example. It flashes after a longer pause.

55 is right. I saw your other post too. There is no 78 so you'll have to recheck that one. I suspect the first "3" you got is really code 12, but it also could be correct. Not all cars bother to display the code 12.