Gearbox, Glad you were able to resolve your problem. My headlight problem is that they go up, but sometimes don't go down until some seemingly random amount of time after turning them off. Anyone know what might cause this?
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Headlights go up...but they don't go down
- Thread starter Gearbox
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Do a little test. Does the headlight retractor maintenance switch, the one shared with the dash light brightness control switch, cause the retractor doors to work as they should? The retractor switch input to the retractable Control Unit is separate from the input from the headlight switch. If the retractor doors work normally using that switch, the problem may be the headlight switch. The headlight switch has four separate switches controlled by the knob. Two of those switches are for the actual headlight / tail light bulbs, the other two are for retractor control and the switches are electrically separate, but, connected mechanically If the two switches that send signals to the retractor module are hanging up, the retractor module may not be getting the off signal and you may be able to fix the problem by taking the headlight switch apart and cleaning and checking the contacts. Be careful with the switch. If you break it, it is mind buggeringly expensive to replace it if you source it from within the US. Page 234-77 of the 1991 service manual has the switch test diagram for checking switch operation.
If the headlight doors have the same delayed close problem when you use the retractor maintenance switch, then chances are that it is the control module that is the problem. Page 23-174 of the service manual has the test procedure for checking the inputs to the module. If all the inputs to the module work correctly then the default assumption is that the module is faulty. Honda does not set out a procedure for separately testing the module. The module may be suffering from capacitor failures and / or circuit board solder fractures that may be repairable. Owners have mentioned this possibility; but, I have not seen any posts covering dissection of the module and identification of the internal problems - you could be the first!
The headlight control motors have rotating switches in them which can bugger up. But, that type of failure would typically be limited to one headlight.
This literally just happened to me! I came home from work and the lights were down. This is a telltale sign of solder cracks because the only thing that changed was that the garage and car cooled off. I'll try to pull the control unit this weekend and see if I can fix the solder joints.
With respect the headlight switch control function, my retractors open up when you turn the switch to headlight; but, they do not go down if you turn the switch back to the running / park light position. They only go down if you turn the lighting switch fully to off. This kind of jives with the diagram of the headlight switch in the service manual which only shows a closed connection to the retractor module in the fully off position.
It appears that that the retractor control doesn't get the down message until the headlight switch is turned off which applies 12v to the red / green wire to the module. Note that the off signal comes through the retractor maintenance switch which also has to be off. If either of those switches is flakey the retractor module may not be getting the closed signal.
It appears that that the retractor control doesn't get the down message until the headlight switch is turned off which applies 12v to the red / green wire to the module. Note that the off signal comes through the retractor maintenance switch which also has to be off. If either of those switches is flakey the retractor module may not be getting the closed signal.
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