New symptom

I have a 1998 Dodge mini sport Caravan, 159780 miles, 3.0 Liter engine, auto transmission, 2 wheel drive, that I purchased in 2001 with 50,000 miles. I just had new front brakes, 2 sensors in the front and back of the C converter replaced, ac charged, timing and ac belt and turning wheel? Replaced. The head gasket leaked when I purchased it but they said it was too costly to repair and I have kept "high-mileage" oil in it for several years. I also had the cruise control replaced a couple of years ago. The mechanic who did the recent repairs said I mainly had original equipment on the van and he was amazed that it had not given me more problems.
My question: I am far, far from home and driving in high heat and my van has begun to chirp. First infrequently, yesterday constantly, today not at all. Sometimes I think it is associated with the ac running but it has chirped w/o the a/c running. Can you tell me if I'm safe on the long distant trip with this or do I have van trouble on the road where I won't know anyone? What is the chirp? What should or can I do to correct this?
Thanks for your help and do I go to the Forum to find your answer or do you ans to my email? Again, thank you so much and how do I donate? Where would I mail it?