Reagan heeding California advice? The President has changed course on the Iran-contra affair a number of times, most recently when he said `mistakes' were made. It appears that Reagan's old political friends in California, perhaps more than his Washington advisers, have been responsible for much of this change.

President Reagan's ``kitchen cabinet'' in California appears to have played a key role in influencing the administration's handling of the Iran arms scandal. These long-time trusted advisers, once an integral part of the White House inner circle, have become less visible since many have left the administration for other pursuits. But in recent days, they appear to have reasserted their influence by helping the President respond to the biggest crisis of his presidency.

The question now is whether the channels of communication will remain open. ``I think the pipeline has reopened - but how much, I don't know,'' says a respected political analyst in the state.

The most dramatic evidence of the California coterie's reemergence occurred over the Thanksgiving holiday weekend, when the President, ensconced at his mountaintop ranch in Santa Barbara, listened - and apparently heeded - the advice of close confidants on several key decisions.

The President came to his sun-dappled retreat exuding unusual bitterness over what he saw as media exaggeration of the crisis and, according to sources, recalcitrance in wanting to deal with it. When he returned to Washington a few days later, he moved quickly to pledge full disclosure of the affair:

He promised that the administration would cooperate with Congress on its investigations.

He threw his support behind the naming of an independent counsel to take over the Justice Department probe.

He agreed on Saturday that ``mistakes have been made'' in the execution of his policy, reversing an earlier position.

``The President has done a complete 180-degree turn since his trip to California,'' says another California political insider.

The President is said to have talked with long-time associates William French Smith, a former US attorney general, and William P. Clark, his former national-security adviser, as well as businessman Holmes Tuttle and political consultant Stuart K. Spencer. ``They told him he had to clean up his act, and open this thing up,'' reports one political analyst who says he is familiar with what went on at the ranch.

Confidants are also reported to have called for a shakeup of the cabinet and White House staff, particularly the ouster of embattled chief of staff Donald T. Regan, something the President has strongly resisted. Mr. Regan has come under increasing criticism, both here and in Washington, for advocating a tough-it-out policy early in the Iran arms crisis as well as for his strong managerial style.

``There's a strong sense among Californians who have known him [Reagan] and worked with him, that the President has got himself surrounded by people who don't have his interests first,'' says Sal Russo, a California political consultant who served on Reagan's staff when he was governor here.

Although the Californians who went with Reagan to the White House in 1980 did not have a lot of national experience, ``they were able to overcome that lack with their closeness to the President,'' Mr. Russo adds.

But many in the California cadre - including Clark, Smith, and Michael Deaver - one by one have left the administration.

Some long-time supporters here fret that, while the people who filled the Californians' shoes are competent and experienced professionals, they lack a personal devotion to the President.

Because the Californians had been with Reagan for 15 years or more, they intuitively understood his feelings, his style, and his constituency, some supporters of the President here say.

It is telling that when chinks began to appear in the administration's armor over the Iran flap, the President turned first to his loyal friend Attorney General Edwin Meese III, one of the few remaining members of the California contingent, says Martin Anderson, a former senior policy adviser in the Reagan White House.

One California Republican insider says it would be ``helpful'' to have some of the President's most loyal friends back in the White House. Adds Dr. Anderson, ``If things ever got to where they were needed, sure, they'd go back.''

The Iranian episode underscores what many consider the President's hands-off managerial style. Some analysts here say the President operates best with a consensus style of governemnt, which they believe Mr. Regan has crimped by limiting access to the President.

The President ``can only function in a collective leadership,'' says one California political insider. ``He cannot with just one strong man around him. His style is a buffet style.''

Some California observers, in fact, say the Iranian arms deals would never have happened if the California associates were still in Washington to act as a restraining influence.

Yet not everyone who knows the President buys this theory.

``The press has this perception that the old-time staff protected the President every step of the way,'' says Californian Esther Greene, a long-time Reagan ally. ``Ronald Reagan has good instincts, and this whole thing comes down to a judgment call.''