I have a 2001 UK-spec Honda ST1100A and am experiencing issues with the headlight. The sidelights and high beam function when using the passing/flash switch, but the main lighting switch does not activate the headlight. I have checked all fuses and bulbs, which are in working order. We have traced the wiring from the handlebar switch to the joint under the airbox and are now attempting to locate the headlight relay for further continuity checks. However, we are having difficulty finding the relay. Although I have the Haynes manual, the wiring diagram colors do not match those on my bike. Can anyone provide guidance on what else to check, the exact location of the headlight relays, or a correct wiring diagram?
headlights not working
- Thread starter benb
- Start date
ST1100Y
Site Supporter
Cleaned the contacts inside the switch-pod yet?
yep
ST1100Y
Site Supporter
Methinks you'll find your wiring diagram here:
There's a relay that momentarily turns the hdlts off when starting the bike. I don't know which one or where it is but check a wiring diagram for it and test that too.
ST1100Y
Site Supporter
EU spec ST have a different setup; lights are not hardwired, but controlled by individual switch; only NO contact underneath starter button, but no NC contact throwing a headlight relay...
I don't know about UK-spec, but the US-spec bikes have a headlight relay that's located under the top fairing, on the main fairing stay in the front of the bike.
The exact location varies from non-ABS, ABS2, etc. so your best info would be available if you have a Honda factory manual for your particular model. That has illustrations showing where the relays are located on the bike. Since you only have Haynes I don't know what it might be able to tell you about location, but wiring diagrams say nothing about where the relay is located.
The exact location varies from non-ABS, ABS2, etc. so your best info would be available if you have a Honda factory manual for your particular model. That has illustrations showing where the relays are located on the bike. Since you only have Haynes I don't know what it might be able to tell you about location, but wiring diagrams say nothing about where the relay is located.