Hollywood vet JAMES BROLIN is reeling from a secret  heartache – his youngest son Jess has become homeless, The ENQUIRER has learned exclusively.
Jess, 39, is the brother of acclaimed “True Grit” star Josh Brolin – but unlike his famous sibling and dad, his life has been filled with failure, say sources.
Josh, 43, and Jess are the sons of the “Marcus Welby, M.D.” star and his first wife, wildlife activist Jane Cameron Agee, who tragically died in a 1995 car wreck 10 years after the couple divorced.
“Jess was left a six-figure trust after the death of his mother and has been living off that ever since,” a close pal told The ENQUIRER. “But that ran out in May, and since then Jess has been living in shelters, staying with friends or sleeping in his banged-up pickup truck on the streets of Oxnard or Ventura, Calif.”
Jess still drives the blue 1981 Toyota truck he inherited following his mother’s death.
“Jess doesn’t seem to do much more than eat and sleep,” revealed the pal. “He likes to read comic books and watch videos when he stays with friends. He complains he has to live on the streets be­cause his family won’t help him. He says they don’t care!”
But The ENQUIRER has learned that Jess has spurned all offers of help from his family, James and Josh Brolin and his stepmother Barbra Streisand.
His 71-year-old fa­ther has repeatedly tried to get him work in the film industry, and has even offered to pay for Jess – who tips the scales at well over 300 pounds – to join a gym or weight-loss program, in addi­tion to offering him a place to stay.
But Jess refuses to accept any of­fers of help from his dad. He was living in an $850-a-month apart­ment in Ventura, Calif., before becoming homeless on May 31.
“Jess was a nice guy, but he didn’t always seem all there,” the building’s  manager, who asked not to be identified, told The ENQUIRER.
The manager described Jess’ living conditions as “disgusting” and his personal hygiene as almost nonexistent.
A family spokesman told The ENQUIRER that James Brolin never gave up on his son.
“We have offered him help and support and will continue to do so,” the rep said. “We love him very much and want only the best for him.”