I have a 2000 Dodge Grand Caravan Sport, 3.3L V6 with roughly 203,000 miles. Within the span of a couple of days, I notice the following symptoms:

• Brake light comes on intermittently when I depress the brake pedal. Sometimes the brake light turns off when I let up, sometimes it turns off the next time I depress the pedal, sometimes it turns off at a random time, and sometimes it doesn't come on at all. I don't really notice any loss in braking ability at all.
• The engine really seems to really struggle going up hills, forcing the transmission to downshift on hills I've never noticed it doing that before--and even then I can't maintain my speed; similarly, even on level roads it accelerates much more slowly than is normal
• The engine seems to start roughly and idle roughly. When the engine is idling but the vehicle is still in motion (e.g. when I let off the gas to go down a hill or to slow down on a level road for traffic/light/stop sign/reduced speed limit) sometimes the tachometer fluctuates, usually no more than 500 or so RPM in either direction.
• When I have the blower running (with or without the AC turned on) and then shut it off but leave the engine running, I get the long, hollow wooshing sound that I've always gotten after turning the AC off, except it's very irregular--it'll seem like it's about to die out and then pick back up at full strength again for a few seconds before repeating--and doesn't stop completely until I turn the engine off (before, it would only happen if I had the AC on and would end after no more than several seconds)

Based on my extremely limited knowledge, I'm wondering if this is possibly a vacuum leak. Obviously there's no way to know for sure without running some diagnostics (which I lack the equipment and knowledge to do, and so wil refer this to my mechanic as soon as he can schedule me in), but being on a budget I'm just trying to get thoughts on how serious this as soon as possible, if only to provide me a bit of hope that it's not going to break the bank.

 

Was any maintenance done just prior to this happening? Is the check engine light on and have you checked for codes? Autozone will check codes for free outside of California. You can read them in your driveway without a scanner.

Brake light - Sounds like the brake light switch mounted on the front side of the brake pedal. Put your ear down there and slowly move the pedal down and back. Listen for a click going down and another coming up. One click? You need a new switch.

Lack of power/rough idle - Yup, vacuum leak. The fact you have performance and idle problems screams it. If you had one or the other I would be looking elsewhere. Intake manifold, EGR valve, tubing are all common sources. Can you hear any hissing under the hood? If there's no leaks it could be an Idle Air Control (IAC) valve problem and/or weak fuel pump.

Blower - Is it defrost related? The A/C will turn on even in the dead of winter when needed when defrost is selected. That woosh can indicate low A/C refrigerant.

 

Not immediately prior, no. I had a new fuel pump put in a couple of months ago along with new spark plugs.

I'll take a look at both of these when I get a chance, which probably won't be for another day or so.

Turns out I had left the defrost on from a heavy rain the other day; guess I just forgot to switch it back.

Thanks for the advice! I'll be sure to let you know what I find out, and what eventually happens.