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BabyG
15-04-2008, 04:47 PM
It seems the headlight failure last night wasn't quite as simple as first thought. Having lost both dipped beam headlights last night, I found both bulbs were blown (both were working when I set off). I now have:
- new bulbs in both dipped beam lights
- headlights pop up when headlights switched on
- no dipped beam when switched on
- tail lights working normally
- when full beam is turned on, all four headlights illuminate (ie including dipped beam bulbs)
- main beam won't stay on, it will only flash as long as the column stalk is pulled (regardless of whether column stalk is pulled one step or both)
- 2*20A fuses on the lighting circuit are fine

I took it to the local (to work) Honda dealer in Milton Keynes to see if they could do anything with the relay (originally diagnosed as the problem) - they took it out of the circuit and shorted the terminals - no better. Given they had to ask where the fuse box was they clearly weren't specialists, but I'm reasonably confident the relay's OK.

Over to you guys - anyone got any ideas of what might be up? I'm baffled.

Cheers,
Rich

mutley
16-04-2008, 08:56 AM
Do you knoiw that there are many different relays for the headlight system and that there is(as far as I know) also a headlight control unit in the bulk head behind the passenger seat.

HTH

Jim

markc
16-04-2008, 12:15 PM
Rich,

If the headlamps pop-up the retractor switch, motors and retractor relays are OK. I think Jim is refering to the headlamp retractor control unit which lives on the bulkhead behind the seats, it sounds like this is OK. The main lighting switch should be OK but could still be a problem.

Pulling the mainbeam switch/lever past the halfway position should activate a relay so it sounds like this, or a connection to the relay, it is the problem.

There are 2 relays for the operation of the headlamps. One called the "Lighting" relay (Main beam) and the other called "Dimmer" relay (Dipped beam).

These are the 2 biggest relays in the relay box under the bonnet. The Dimmer relay is the bigger of the 2 and has 5 pins, the Lighting relay has 4 pins.

If you haven't changed both of these already I would do so if I were you.

If it still doesn't work, I'd look at the main lighting switch or possibly a wire/connector between it and the "Lighting" and "Dimmer" relays.

Hope this helps.

Mark

BabyG
16-04-2008, 06:21 PM
Crikey, you guys know your stuff - much appreciated! I had in my ignorance only been looking at the four pin lighting relay - hopefully it will be the 5 pin dimmer that's the problem. Hopefully I can report back tomorrow with some progress.

duncan
16-04-2008, 07:26 PM
The dipped beam is supposed to stay on when the full beam is on. If you look at the wiring diagram you will see that for each side seperately switching the headlamps on, switches both the full and the dip beam bulbs on simultaneously, they have a common power lead. The dipped beam drops straight to earth and therefore should illuminate immediately, the earthing to the full beam is via the full beam relay [which is on the earth side of the bulb not the power side]. As neither full or dip work on the rotary switch, but both do on the flasher switch, AND the failure is to both the LHS and RHS; I would suggest checking the power to the rotary switch.

BabyG
17-04-2008, 05:51 PM
Hmmm. Seems it's not the relays. After much time poring over the impressively tatty service book at Norton Way, the main headlight switch is the main suspect. I'll find out tomorrow once they've tested it. Apparently it has several connections within it, so it is feasible that it could trigger the popup without the power circuit.

Time to find out if anyone's breaking a headlight switch...

nigel
18-04-2008, 05:04 PM
Sounded like a bad switch from the beginning but I wanted to keep my gob shut until I saw more info. To many variables to be anything other than an internal switch problem. It can be caused by bashing it while getting in if you hit hard with your knee or ?
Try and find a switch from a breaker or possibly Dirk. They do go bad inside and mostly can't be repaired when they do.
You don't want to know how much they are new from Honda.

Cheers
nigel