* 1/2 THE RED HOT CHILI PEPPERS. "The Uplift Mofo Party Plan." EMI-Manhattan. The Chili Peppers apparently have to be seen to be appreciated. That's a semi-diplomatic way of saying this kooky quartet has made very mediocre records in the last two tries. The spunky funksters' previous LP, "Freaky Styley," was produced by their sonic ancestor George Clinton--a pairing that looked much better on paper than it worked on vinyl. "Plan," the group's third effort, is another hit-and-miss affair. Although none of the "hits" is likely to be of the chart-topping variety, a song with the tender tunefulness of "Behind the Sun" proves that the outfit isn't strictly anti-melody/pro-raunch. And this any-rap-goes foursome extends its tradition of intriguing outside material with a knucklehead-funk version of Bob Dylan's "Subterranean Homesick Blues." But the rest are originals, most of which wear pretty thin pretty fast, further suggesting that this is a band that's in command on stage--but in trouble in the studio.