[Jetdoc]

There are 2 fan relays. 1 radiator fan main relay and 1 radiator fan relay. You deffinately have a cooling fan issue due to it only overheats when you slow down or stop. These relays are in the underhood relay box. You can swap them wit like ones next to them for troubleshooting. Swap them one at a time and see if the fans start working.
s55lear just had this same problem today in this thread.

 

[Jetdoc]

Miked had posted pics of all this but his pics won't work. You need some kind of manual. If you plan on maintaining your Legend yourself it's a must have.
The long rectangular closest to the radiator is the one where all the cooling fan relays are. Standing in front of the car you will see from your left to right, 3 big relays and 4 smaller ones. The 2nd big relay is the radiator fan main relay, swap it with the 3rd big relay which is the windshield wiper intermittant relay. Test drive it. If the fans work correctly and the intermittant wiper don't work correctly then you know what the problem was. If this is the case then swap them back and put the new relay in the radiator fan main relay position. I think you can get these relays at most auto parts stores.

 

[Jetdoc]

Ok now we will swap the condenser fan relay.

These #'s will represent the relays. 1,2,3 are the big relays and 4,5,6 are the small ones. c is the red connector.

------6 c
1 2 3 4 5

4 is the condenser fan relay
5 is the radiator fan relay
6 is the horn relay

Swap #6 horn relay with #4 condenser fan relay. If no help try swapping #6 with #5.

Does your a/c work? does the a/c compressor come on when you select a/c?
If you don't have enough freon in the a/c system the condenser fan won't come on.

 

[Jetdoc]

Did you try getting all the air out by doing this.......
Do this:
first turn the heat to full hot(opens the heater control valve to let coolant flow). *with ignition switch on.
1. Open bleeder at thermostat housing and remove radiator cap(not resivoir cap).
2. Pour coolant into radiator until a steady stream of coolant without bubbles comes out bleeder.
3. Close bleeder.
4. Leave rad cap off and start engine. As engine warms up top off coolant as air burps out.
5. Massage upper radiator hose to help get air out.*CAUTION COOLANT IS HOT AND WILL BURN YOU* if you squeeze the hose too hard and coolant splashes out on your arm.
6. When engine reaches normal temp it should be good to go. Install radiator cap.
7. fill coolant resivoir to proper level.
8. Drive vehicle and monitor temp. After engine cools down completely remove rad cap and top off if necessary.

If you are sure you have a BHG you can try removing the thermostat and operating without it. This will sometimes work until you can make repairs. The heat wont work very well and your gas milage will drop but you can still drive it.