'99 - no automatic headlights

I have a '99 with a W in the VIN & 105K. The headlights on this vehicle usually come on when the van is on. Right after having the tranny rebuilt (maybe coincidence), the headlights don't come on automatically and have to be turned on manually.

Any suggestions where to look?

Thanks!

I believe you are rferring to your Daytime Running Lights (DRL)- since I am not familiar with M vans having automatic headlamp controls - those that come on when it gets dark-- so here is how your DRLs are supposed to work: Hint- I'd make sure the parking brake is fully pulled back.....first

The Daytime Running Lamp (DRL) operates automatically with the ignition switch in the following positions:

• RUN

• BULB

• TEST

The DRL also operates automatically under the following conditions:

• The parking brake is disengaged.

• The headlamp and panel dimmer switch is in the OFF position.

Operation of the DRL reduces the intensity of normal high beam operation.

Voltage is applied through the gauges fuse 4 to the DRL module and to the coil (power side) of the DRL relay when the ignition switch is in the following position:

• RUN

• BULB

• TEST

• START

If the parking brake is disengaged and the headlamp and panel dimmer switch is off, then the DRL module supplies ground to the coil (ground side) of the DRL relay. With power and ground applied to the coil of the DRL relay, the coil energizes the contacts to close. Voltage is applied through the DRL fuse 15 and the closed contacts of the DRL relay to the left and right low beam headlamps. When the DRL is operating, the DRL module supplies ground to the DRL indicator.

Voltage is applied through the gauges fuse 4 to the DRL indicator with the ignition switch in the following positions:

• RUN

• BULB

• TEST

• START

With power and ground applied to the DRL indicator, the DRL indicator illuminates.

When the parking brake is engaged, the DRL module senses a ground signal. When the DRL module receives the ground signal, the DRL operation is disabled. DRL operation is disabled by removing the ground from the coil of the DRL relay.

The DRL module disables the DRL operation under the following conditions:

• The headlamp is in the ON position.

• The panel dimmer switch is in the ON position.

• The ignition switch is in the following positions:

- OFF

- LOCK

- ACCY

• Removing ground from the coil of the DRL relay.

Make sure the park brake is fully released. Try the dome lamp over-ride switch in two quick ON-OFF-ON cycles to enable the DRL and auto headlight function. Check the fuse in the UEC, the DRL relay, and the diode in the same panel.

FWIW, my 2000 also has both DRL and auto headlights.