2.5.3 Heat resistance (1) Testing Place the connector with a bulb in a thermostatic chamber kept at 90C, and then apply a current of 5A to the bulb for 300 hours. For this test, use an electric wire of 0.5 sq for connection. (2) Performance The temperature on the reverse side of the terminal caulked portion shall not increase more than 10C during and after the test. 2.5.4 Resistance to combined environment 1) Testing Arrange the headlamp assembly and the wire as indicated in Fig.2.5.2 and vibrate them under the following conditions for 300 hours (75 cycles), while varying the ambient temperature with the headlamp bulb always on. Ambiet temperature: Vary it in the pattern shown in Fig.2.5.2.2) Performance The temperature on the reverse side of the terminal caulked portion shall not rise above 200C during and after the test.