Thank you all, Stevebfl, Gilly, and Deanyel. I feels release that this relay is only cost $77.35. Reading other posts, I saw it cost 275 buck. I will buy next week.

I think I nail down the problem. It is the combination relay N10. The following is what I did. I pull out the schematic diagram form MB CD it call "Model 124 Exterior Lighting". Took out the Combination Relay N10. It is behind the fuse box. You have to lift up the cover (6 screws) before you can see the relay and it is Relay H. This relay is for turn signal/hazard signal, windshield wiper motor and rear defroter. Do some testing. The test is as follow:

1. Check Socket 2 (wide W1 to ground) and it shows very low resistance and is o.k

2. Turn hazard switch on, check voltage between Socket 8 (positive) and Socket 2 (negative) and get battery voltage around 12 V and it is o.k. If it is not then fuse #6 or the hazard switch is bad.

5. Turn ignition on, hazard switch off and check voltage between Sock 8 and Socket 2 again and it should be 12 V. If it is not, then fuse #9 or the ignition switch is bad.

6. Turn hazard switch on, jump a wire from socket 8 to socket 10 (this is the contact that provide power to socket 10 when the coil is energized), all turn turn signal lamps should be on (2 on the right and 2 on the left). If not, then the wiring to or the bulb is bad.

7. Turn ignition on, turn Right signal on. Jump wire socket 8 to socket 10. right side signal lamps should be on. Turn left signal on and left side signal lamps should be on. If not then the wiring to or the bulb is bad.

If all tests are satisfactory, then the combination relay is bad.

I also disassembled the N10 relay and found some burning/melting in the soldering of circuit board. Definitely, the relay problem.