87 sporster brake and run prob.
Thread Starter
|
Advanced
Joined: May 2008
Posts: 84
Likes: 3
From: Groveland, CA
87 sporster brake and run prob.
Hi, I have a 87 sporster and trying to figure out a wire problem. The run and brake light are both on when bike is running or ignition is on. The tail light has only two wires and running a 1157 dual filament. Should the tale light have a ground. I ran a ground wire from the light to a clean spot on my fender which did not do anything. Could anybody give me some advice what to look for. The brake light switch is new as is the bulb. Thanks for any help in advance
Ultimate HDF Member
Joined: Aug 2010
Posts: 5,014
Likes: 739
From: Northern California
If you don't get the answer here https://www.hdforums.com/forum/sport...sportster.html
check out http://xlforum.net/forums/
check out http://xlforum.net/forums/
Last edited by mmesa005; May 11, 2018 at 10:18 PM.
Seasoned HDF Member
Joined: Feb 2007
Posts: 6,072
Likes: 1,124
From:
1. Is the bulb a regular 1157 incandescent ? Was the bulb tested off the bike with a battery in order to confirm that one filament in the bulb is not broken and touching the second filament? Side of bulb is negative will the contact points on bottom are for positive ( a brand new 9 volt battery is good for this test and requires no wires)....Did someone brutally force bulb into socket causing it to sit incorrectly and be touching both contact points at bottom of socket?
2. Was a meter or test light used to confirm presence of 12 volts dc at the two contact points at bottom of bulb socket?
Method:Negative test lead to socket bare metal housing and then other lead touching one contact point at bottom of socket to review reading and then using same probe touching second contact point to take reading?
That is done to confirm BOTH positive contact points at bottom of socket have 12 volt power.
3. Now we need to look at brake switches...You report in post #4 that no brake switch is on handlebars...why? How do the two wires terminate at the handlebar?
Reason: someone that would not know function of switch might splice those wires together causing brake light to stay ON, instead of leaving them separated....or someone that would not understand operation of switch would leave switch hanging and that would cause brake light to stay ON since switch functions backwards..(plunger out is ON and OFF is with plunger in)
4. Then because a rear switch is NEW, it does not mean the switch is functionally correct...Disconnect rear switch electrical and review for element to turn OFF.
5. If rear of bike has been lowered then review wires under rear fender for damage.
6.Check for pinched wire at right handlebar switch clamp or if running internal wires in bars.
7. Ground (-) comes from frame, in this case the metal socket wall.
Review the above and let us know how it went.
2. Was a meter or test light used to confirm presence of 12 volts dc at the two contact points at bottom of bulb socket?
Method:Negative test lead to socket bare metal housing and then other lead touching one contact point at bottom of socket to review reading and then using same probe touching second contact point to take reading?
That is done to confirm BOTH positive contact points at bottom of socket have 12 volt power.
3. Now we need to look at brake switches...You report in post #4 that no brake switch is on handlebars...why? How do the two wires terminate at the handlebar?
Reason: someone that would not know function of switch might splice those wires together causing brake light to stay ON, instead of leaving them separated....or someone that would not understand operation of switch would leave switch hanging and that would cause brake light to stay ON since switch functions backwards..(plunger out is ON and OFF is with plunger in)
4. Then because a rear switch is NEW, it does not mean the switch is functionally correct...Disconnect rear switch electrical and review for element to turn OFF.
5. If rear of bike has been lowered then review wires under rear fender for damage.
6.Check for pinched wire at right handlebar switch clamp or if running internal wires in bars.
7. Ground (-) comes from frame, in this case the metal socket wall.
Review the above and let us know how it went.
Outstanding HDF Member
Joined: Feb 2015
Posts: 2,414
Likes: 433
From: Arkansas
Unless you are running an aftermarket run/brake kit the rear signals should be 1156 single filiment sockets with 2 wires (ground/power). Fronts are 1157 3 wire sockets ( run/turn/ground).
Thread Starter
|
Advanced
Joined: May 2008
Posts: 84
Likes: 3
From: Groveland, CA
Ok it is a regular 1157 bulb. This bike was set up to fire up without the lights on at the ignition. One click no light can fire up. Two clicks lights on and can fire up. On the one click position no lights on if you hit the brake pedal the brake light comes on. When on the second click position both the brake and running lights up at the bulb. There is 12v at the running light side of the light and only 12 v when you hit the brake pedal at the other side. This is when you have the lights on or two clicks position on the ignition. Not sure why it was set up like this but to make it fire up easier when firing up on a low battery etc. The bulb checks out good on a test as does the brake switch. Not sure if someone was forceful etc at the bulb socket or not. I was having trouble getting a volt reading at the socket so maybe it was abused etc. The springs both work at the socket etc. Someone must have changed the tail light from stock as it is 1157 and not the 1156 style. The front switch was removed completely from the bike at the grip.
Thread
Thread Starter
Forum
Replies
Last Post
