Thalang Police were called to the scene, in front of the Paraphan Pa Khlok shop in Moo 4, Pa Khlok, at about 11am.
The driver, Pairin Phetthong, was unharmed in the incident.
Mr Pairin explained that he had left the Tha Reua branch of Newkee Engineering Services and was on his way to Phang Nga when he noticed smoke coming from the box on the back of the pickup.
He pulled over and quickly started taking the air-conditioning units out from the back of the pickup. However, several of the air-conditioning units had been damaged by the fire.
Local residents came to help and doused the pickup with a fire extinguisher before police arrived.