Truck kicking w/headlights on

Like the title says..
My 2.3L '96 Ranger kicks and acts up if I run it with the headlights on. It's not SEVERE, but it's definitely an issue.
Once I was told that there was a problem with a solinoid? I think it was.. and that it could be rebuilt. But when I went to the place, the guy there tested and said there wasn't a problem with it.
Did it get worse, and now DOES need rebuilding? Could it be something else? Am I misremembering what the guy told me?
I just had a diagnostic done, and they never mentioned any of that. Could the PCM cause the issue with the headlights?

Solenoid? The only ones used in normal operation are solenoid valves within the injectors, air bypass valve, and transmission. NONE of these are your problem. Whoever told you that was your problem is simply not worth listening to on this subject.

The PCM might be screwing up, but for you to blame it would require it to respond to headlights inappropriately. You're clearly guessing.

I'd suspect the electrical system is browning out.

If your diagnostic didn't include that, you need another diagnostic. Just what was done? There is much more to diagnosis than plugging a code reader into the port and reading stored codes. This wasn't done at an auto parts store, I hope (that's nothing more than a waste of time -- diagnosis really does require distinguishing one's rear from a hole in the ground).

The old diagnostic where they mentioned the solenoid was at a oil change/mechanics.
I mentioned the PCM, because the truck is having a issue with bucking and kicking, and having NO power when in gear, and I had a full(they said) diagnostic run by a mechanic, who said the PCM was bad(causing the kicking etc, NOT the headlights issue) and that there might be also the DPFE, the EBR(insufficient flow?) and possibly the O2 sensor.
The note from the mechanic says that it was "Diagnostic Scan Computer for DTC's Memory codes". It has some number codes on it too, it's just hard to read the writing, would they help? Is this even posted in the right spot?
I just thought to ask about the headlights being on/causing rough running, when I saw a thread mentioning that. I'd forgotten to mention it to the mechanic, but assumed that a diagnostic run by the mechanic would also come up with any problems relating to that issue too.
Thanks for replieing, I don't know what I'm talking about, that's why I was happy to find a place like this!

With all these problems, I'm EXTREMELY skeptical that the PCM is causing them all. Even if you leave the headlights out. It's possible, of course, and to really know, I'd have to know the mechanic's processes.

You can explain every one of these problems, for instance, by poor grounding. Has that been ruled out?

DTC scans are not a "full diagnostic." Every code comes with a service checklist.

As a check, how much time did they claim this DTC scan took? I'd expect around an hour if this guy did what he was supposed to do.

And the "possibly" on the O2 sensor triggers red flags for me. These are not that hard to isolate.

I think it took about an hour. I walked to McDonalds to eat, and came back to sit. The tech was in my truck when I came back, and they didn't say it was finished for at least 45 minutes or so.
So, should I try to get a diagnostic from another mechanic? Or should I replace the Powertrain Control Module? It's almost easier to get the darned part(which I have to prepay for, and get it the next day) than to get a diagnostic done by a honest mechanic.
I did get the quote from him of $360 to replace the PCM.
I found the part for.. $170? minus about $50 core charge I think it was.
Sighs.

Don't throw parts at it, man. Find a good mechanic, that knows how to check the basics, first, and if the truck has codes then knows how to test and diagnose properly from there. It's hard sorting out what you've got going over the internet, but the headlights having an effect as described would have me checking all of the grounds throughout the truck, very first thing. I know that it's frustrating when you're having truck trouble, but replacing parts and praying usually don't work (well, there is a lot to said about prayers, in general I guess, except to fix your truck). Good luck!

Okay. Find someone to diagnose again. Have them check the grounding.
Can a place like Autozone do that? I will be calling my local place(diff local than today's) and seeing if they can look at it tomorrow, since I'm not working tomorrow. I know Autozone does free diagnostics, but I read online that they aren't good at that?
It is frustrating, since there just doesn't seem to be decent mechanics to DO this. Not in my area anyway.

not to sure about autozone helping you find ground issues. wish you were closer, I would be able to help in person, as I love electrical stuff and am very good at finding bad grounds or broken wires or whatnot. unfortuantely I really can't help much here except ry to find a good "honest" mechanic. good luck dude I hope you get it sorted out.

Autozone "diagnostics" are plugging in a code reader and telling you what codes are there. Generally, not even including "pending codes."

IMO, they should be flogged with an OBD-II cable for calling that "diagnostics." Kinda like going to the dentist and having him peek inside for 2 seconds and then saying "OK, you're done."

Okay, so...
I went to my other mechanic locally. He SAID he could run a diagnostic, but when I got there, he just ran the codes, and then said that it was an old code, so he wasn't sure if that had anything to do with the problem.
He wiped the old codes out, and that turned off the check engine light.
Said "Call me if the light comes back on".
I decided that poor or not, it couldn't hurt to have AutoZone run the codes too.(even though it wasn't a 'diagnostic', and I could have them price the parts that the first mechanic said I needed).
I drove (30 minutes?) to Autozone, but the check engine light stayed OFF, even though the truck acted up on the way. Autozone of course said, no engine light, no codes. They did check, but it said 0 codes.
He ran through the stuff from the 1st mechanic's diagnoses, and said HE thought I should replace the EGR valve(that it might be clogged only). But I think I read online, that it's rarely the EGR valve, but a lot of times the DPFE sensor? That's attached to the EGR valve? Asking him that got a "Hmm, no.. well, you could remove the EGR valve, and we can run a vacuum test on it".
But I can't do that, I only have ONE vehicle.
So I left there, without ordering any parts.
On the way home, the check engine light popped back on, so I called my other mechanic(from that morning) and he said come in, and he'd run the codes for me agian.
HE said the only code that came up was saying the distributor was bad, but that the truck doesn't have a distributor.
What?? Did he just read the wrong set of code books?
Anyway, he says to let him have the truck for a day or two, and he's certain he can find out what's wrong. He further said he doesn't think it's the PCM, since he's worked on tons, and only had to replace that twice in hundreds of trucks.
THEN.. I called my cousin who works on vehicles, and he said maybe it could be a clogged catalytic convertor, and that I should unbolt the muffler system, and see if I still had issues with the truck, with that unhooked to allow release of exhaust pressure.
So..
While I bang my head against the wall, any ideas? I'm guessing at this point I will have to let the mechanic #2 look at the truck(he said something about the crank, or crank sensor?) since he at least DID say "Let's try to find out what's WRONG, rather than replacing a bunch of stuff."
I really appriciate this place, and I've read through a LOT of threads, to see if anything applies to my situation.
Thank all of you for taking the time to try to help me, even if I am totally stupid here.
edit: sorry, forgot to mention, the grounds DO seem to be fine

Jeez, he doesn't know that the ignition diagnostic monitor code isn't synonymous with a distributor? Can he read without moving his lips? You have an IDM if you have electronic ignition, regardless of whether it's attached to a distributor or not.

This mechanic doesn't appear to be competent. Unfortunately, that happens.

If you're going to go with a clogged cat, you need to explain how that affects your headlights. I don't buy it for an instant. This is clearly electrical, somehow.

And it's VERY easy to diagnose an EGR system without disassembling it. You look at its inputs and outputs. For your own sanity, pay NO attention to what is "common." Yours may not be and if it isn't, you will be thoroughly confused. Plugged EGRs happen sometimes.