Electrical problem help
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Tourer
Joined: Jun 2010
Posts: 411
Likes: 23
From: Alabama
Electrical problem help
On my 2018 Road glide ,right rear turn/run /brake light.Light works,turn signal works but when brake is applied the light goes out.No codes wiring is connected..I am stumped.I changed bulbs and still same.Have the wrap around saddlebag lights and they both work correctly.Thanks for any help.;
Seasoned HDF Member
Joined: Jan 2008
Posts: 13,601
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From: State of Confusion
On my 2018 Road glide ,right rear turn/run /brake light.Light works,turn signal works but when brake is applied the light goes out.No codes wiring is connected..I am stumped.I changed bulbs and still same.Have the wrap around saddlebag lights and they both work correctly.Thanks for any help.;
Road Master
Joined: Apr 2018
Posts: 1,171
Likes: 709
From: Indianapolis
I have a 2018 service manual. First thing I noticed is in figure A-24 "Rear Lighting". There's a facia/converter module shown between the lights and the harness. No details on what this module actually does. So, if I were to troubleshoot this, I'd disconnect the main harness from the module and break out the volt meter. Based on the diagram, the connector should have 12 positions. Positions 2, 8-11 should be empty. Pin1 is black, pin 12 is R/Y.
****I'm making an assumption here that the system doesn't stop working because it can detect it's disconnected.
1) Check pins 1 & 7 for ground.
2) Pin 12, R/Y for 12V with key power on (power from BCM).
3) Pin 3, Bl/Br, should flash 12V with front right turn signal.
4) Pin 4, Bl/V, should flash 12V with front left turn signal.
5) Pin 5, Bl/R, should go to 12V with brake applied.
6) Pin 6 Blue, should be 12V constant. This is the tail/running light.
If I understood right, the right signal light is on with the running light, and goes bright for the turn signal. But when you hit the brake, it goes out completely. What if you have the right turn signal on AND the brake? Does it still flash? I wouldn't think it would be the BCM since all the functions seem to work independently. Right now, that module seems very suspect. And I agree with the advice about warranty. As long as you didn't buy your '18 more than 2 years ago.
****I'm making an assumption here that the system doesn't stop working because it can detect it's disconnected.
1) Check pins 1 & 7 for ground.
2) Pin 12, R/Y for 12V with key power on (power from BCM).
3) Pin 3, Bl/Br, should flash 12V with front right turn signal.
4) Pin 4, Bl/V, should flash 12V with front left turn signal.
5) Pin 5, Bl/R, should go to 12V with brake applied.
6) Pin 6 Blue, should be 12V constant. This is the tail/running light.
If I understood right, the right signal light is on with the running light, and goes bright for the turn signal. But when you hit the brake, it goes out completely. What if you have the right turn signal on AND the brake? Does it still flash? I wouldn't think it would be the BCM since all the functions seem to work independently. Right now, that module seems very suspect. And I agree with the advice about warranty. As long as you didn't buy your '18 more than 2 years ago.
Road Master
Joined: Dec 2018
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From: Florida
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Club Member
Joined: Dec 2014
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From: SWFL
When did it start? Prior to it happening did anything change? I.e, saddlebag light installed? First thing id do is remove the saddlebag light module from the harness and see if it resolves. As I recall its just two plugs.
Last edited by Mchad; Mar 26, 2020 at 06:37 AM.
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Tourer
Joined: Feb 2016
Posts: 349
Likes: 83
From: Florida
+1
if its a dual filament bulb which i believe it is it has to be inserted correctly or else it will not work as the polarity for the second filament is grounded instead.
remove the bulb and try installing the other way.
if its a dual filament bulb which i believe it is it has to be inserted correctly or else it will not work as the polarity for the second filament is grounded instead.
remove the bulb and try installing the other way.
Club Member
Joined: Dec 2014
Posts: 10,734
Likes: 3,755
From: SWFL
Aren't 1157 bulbs keyed? i.e. can only install one way? I guess one could force it, but thats just silly.