For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Check the fuse Ef25. Is the fuse blown? | -- | Go to Step 2 | Go to Step 3
2 |

1. Check for a short circuit and repair it, if necessary.
2. Replace the blown fuse.

Is the repair complete?

--

System OK

--

3 |

1. Turn the ignition ON.
2. Depress the defogger switch to turn on the defogger system.
3. Use a voltmeter to check voltage at Ef25.

Does the voltmeter indicator the specified value?

11-14V

Go to Step 4

Go to Step 5

4 | Check the poor connection of I/P fuse block and repair it, if necessary. Is the repair complete? | -- | System OK | --
5 | Check the open circuit between fuse Ef25 and BCM and repair it, if necessary. Is the repair complete? | -- | System OK | --