The USS Los Angeles attack submarine President Carter rode in yesterday is wired to receive orders from a doomsday communications system that the Navy can't get built.

When the Los Angeles was only a paper design a decade ago, the Navy figured that by now it would have in place at least a test version of the Sanguine underground communications grid to tell submarines what to do if war came.

But the technical problems of building the $237 million, nuclear-powered Los Angeles - which at 360 feet is longer than a football field - have proved much easier to solve than the political problems of finding a home for Sanguine.

As one of his last official acts, former Defense Secretary Melvin R. Laird kicked the Sanguine doomsday communications grid out of his home state of Wisconsin.

Then the Navy, with no success, tried to convince Texans that Sanguine would not harm their ranching and was vital to the national defense. But fears that Sanguine would harm the environment - especially cattle and deer - overwhelmed Navy pleadings.

Now the Navy is trying to make the case for Sanguine, since renamed Seafarer, in Michigan. The Navy would like to put the grind in Michigan's Upper Penninsula where a layer of rock would help form the long radio waves needed to reach down to submarines in the depths.

Without Seafarer, the Los Angeles and other submarines will have to continue to come close to the surface to receive radio messages, risking giving away their positions in the even more sophisticated hunting game the United States and Soviet Union are playing.

"I know of no near-term alternative for communicating with submerged submarines short of having to put an antenna near the surface and running the risk of detection or otherwise constraining maneuverability," Defense Secretary Harold Brown wrote recently to chairmen of congressional committees which handle the Pentagon budget.

"The need" for Seafarer, he wrote, "is real and urgent for peacetime, crises and conventional warfare as well as for strategic war." Navy Secretary W. Graham Claytor, in separate letters, recently pleaded with congressional leaders to vote the Navy $20.1 million for Seafarer for fiscal 1978.

In hopes of dereasing the opposition that has developed in Michigan to Seafarer the Navy is considering building two smaller grids for communication with submarines like the Los Angeles. One grid would be in Michigan and a second in Wisconsin to take advantage of the buried rock formation in both states.

A Seafarer system to send radio waves deep into the ocean is considered by undersea warfare specialists as especially important to the Los Angeles class of attack submarines. Congress has authorized the Navy to build 31 Los Angeles subs and it is hoping to buy more.

For one thing, the huge size of the Los Angeles - 360 feet long and 33 feet wide - makes it easier for an enemy to detect than smaller submarines. And even though it is powered by a giant nuclear reactor, critics charge the Los Angeles is neither as fast nor as quiet as desired when the new ilass of attack boats was being planned.

Also, informed sources state, the Los Angeles cannot dive as deep as older attact submarines, making it more vulnerable to both detection and destruction.

Anything that increases the Los Angeles' vulnerabilities, such as having to rise near the surface at specified intervals to receive radio messages, ades to the worries undersea warfare specialists already have about this newest attack submarine.

The Los Angeles is basically a submarine killer. It has a mix of Mark 48 torpedoes and Subrov missiles that can be fired out of the submarine's four torpedo tubes.

Attack submarine crews constangly listen through elaborate equipment for other ships and submarines in hopes of hearing them first.