Brake Light Issue

[StuartKeith]

Hi guys. for some reason my brake lights are no longer working, They were fine before I swapped the engine out, but now neither the front nor rear brake light come on, upon pressing the pedle or touching the front wires together.

I cant belive the bulbs would bother blow just being sat for a year, so any suggestions where to start?

THanks

Stu

 

[Andrew Shadow]

Check the fuses for power entering and exiting.
Power entering and not exiting means the fuse is blown. Find out why it blew and repair it.
If the fuses are good, remove the bulbs and check for power and ground at each turn signal bulb connector.
If there is power at the turn signal connectors when the switches are activated, and if the ground tests good, the bulbs are no good.
If there is no power at all of them, check the brake light switches for power entering. Check them for power exiting when the switches are activated.
If there is no power entering the switches, there is an open in the wire between the fuse box and the switch.
If there is power entering the switch but not exiting, the switch is faulty.
Because the lights do not work when either switch is activated, and if you have determined that there is no power being supplied to the bulb connectors, look first at the locations where the wiring between the front and the rear switch is common. You'll have to check the wiring diagram to find out where those are.

 

[StuartKeith]

Check the fuses for power entering and exiting.
Power entering and not exiting means the fuse is blown. Find out why it blew and repair it.
If the fuses are good, remove the bulbs and check for power and ground at each turn signal bulb connector.
If there is power at the turn signal connectors when the switches are activated, and if the ground tests good, the bulbs are no good.
If there is no power at all of them, check the brake light switches for power entering. Check them for power exiting when the switches are activated.
If there is no power entering the switches, there is an open in the wire between the fuse box and the switch.
If there is power entering the switch but not exiting, the switch is faulty.
Because the lights do not work when either switch is activated, and if you have determined that there is no power being supplied to the bulb connectors, look first at the locations where the wiring between the front and the rear switch is common. You'll have to check the wiring diagram to find out where those are.

Ok it turns out the fuse is blowing as soon as the ignition is on. I have unplugged th eindicator relay and all the swich harness for the brakes, but it is still blowing. Indicators are also not working now, so something has happened.

The only thing I have done since putting the engine in and testing is replacing the tank.

 

[ST_SVK]

It looks like you squeeze some wire between tank and frame, or damaged one, so you have short circuit somehere.

Try to put fuel tank out and check there for any shortage.

 

[SMSW]

A fuse blowing as soon as the ignition is turned on usually means a dead short - what ST_Svk said is very likely. Easiest way to find the problem would be to visually track all of the wiring bundles and see if any are caught between the frame and engine. This, I'd think, will be easier than the other way - id the wire color from the fuse and, using the wiring diagram, follow it from connector to connector checking continuity to ground as you go. One section of hte wire will be grounded. I'm guessing that you really did not touch the signal lampholders and make the short yourself.

 

[StuartKeith]

A fuse blowing as soon as the ignition is turned on usually means a dead short - what ST_Svk said is very likely. Easiest way to find the problem would be to visually track all of the wiring bundles and see if any are caught between the frame and engine. This, I'd think, will be easier than the other way - id the wire color from the fuse and, using the wiring diagram, follow it from connector to connector checking continuity to ground as you go. One section of hte wire will be grounded. I'm guessing that you really did not touch the signal lampholders and make the short yourself.

Nope, all I have done is swap the engine out after a belt failure. of course, I unplugged all the connectors. The wire according to the diagram is white with green. not sure where that cable runs. I am thinking maybe the tank has caught it, as when I tested the engine, the tank sat on top and not in the frame, now its in the frame. As I have unplugged everything from that circuit I know off, it must be something catching

 

[SMSW]

Nope, all I have done is swap the engine out after a belt failure. of course, I unplugged all the connectors.

Swapping engines is a pretty big task. If everything worked before and something does not work now, then it is reasonable to assume that something was not put back together the way it was before - or a wire was pinched in the process. Another thought, though I would think Honda would take steps to avoid this possibility is two similar connectors were cross connected. Were this the case, then something else would not work, so it is unlikely.

 

[Larry Fine]

A quick and cheap troubleshooting tip is to temporarily replace the fuse with a high-wattage12v bulb.

Steady full brightness indicates a direct short; flickering means an intermittent short; off means fixed.

 

[Andrew Shadow]

Ok it turns out the fuse is blowing as soon as the ignition is on. I have unplugged th eindicator relay and all the swich harness for the brakes, but it is still blowing. Indicators are also not working now, so something has happened.

The only thing I have done since putting the engine in and testing is replacing the tank.

Indicators are not working now because you removed the turn signal relay.
You have a wire pinched and shorting to ground somewhere. You will have to hunt it down.

 

[Larry Fine]

Again, try my suggestion above. The bulb acts as a combination of a current limiter and a ground indicator, so you can keep voltage on without blowing another fuse, and have a real-time indicator that will let you know when you're wiggling wires in the right place.

As an electrician, I have done this many times to troubleshoot short circuits on 120v circuits.

 

[Larry Fine]

Ok it turns out the fuse is blowing as soon as the ignition is on.

That tells us that the short is on the green/white wire, which only goes three places: the front brake switch, the rear brake switch, and the turn-signal flasher socket.

 

[gcos]

A quick and cheap troubleshooting tip is to temporarily replace the fuse with a high-wattage12v bulb.

Steady full brightness indicates a direct short; flickering means an intermittent short; off means fixed.

That is an excellent tip - I never would have thought of that but it makes perfect sense. Really excellent simple check.

 

[StuartKeith]

That tells us that the short is on the green/white wire, which only goes three places: the front brake switch, the rear brake switch, and the turn-signal flasher socket.

Someone has said because it's blowing without anything connected the short is somewhere between the fuse box and relay socket? Dose that sound correct? I think I have a blown h4 bulb for van that Hb works on so can try the bulb trick

 

[ST_SVK]

@StuartKeith: if everything (even relay) is disconnected and it still blows the fuse, than you are right, you have shortage somewhere between fuse and relay. Search the way.

Bulb trick is good one.

 

[StuartKeith]

Swapping engines is a pretty big task. If everything worked before and something does not work now, then it is reasonable to assume that something was not put back together the way it was before - or a wire was pinched in the process. Another thought, though I would think Honda would take steps to avoid this possibility is two similar connectors were cross connected. Were this the case, then something else would not work, so it is unlikely.

Was working after swaping engine just without tank on so will tank the tank back out later. I have also fitted the battery back in and connected all the access wires back so will remove all of them as well.

 

[Larry Fine]

Someone has said because it's blowing without anything connected the short is somewhere between the fuse box and relay socket? Dose that sound correct?

As I said, that one wire splits to go to three places, the flasher module (not really a 'relay') socket and both brake-light switches. A short can be on any branch of that wire; the flasher socket is only one of the three.

By the way, the solid-green wire on the flasher socket is ground, and should not be connected or used by any modern flasher module.

I think I have a blown h4 bulb for van that Hb works on so can try the bulb trick

That would be a good bulb wattage for this use. A couple of alligator-clip jumpers would be very useful.

 

[Andrew Shadow]

I think I have a blown h4 bulb for van that Hb works on so can try the bulb trick

That would be a good bulb wattage for this use. A couple of alligator-clip jumpers would be very useful.

A blown bulb will yield no result, it needs to be a functional bulb doesn't it?

 

[Larry Fine]

A blown bulb will yield no result, it needs to be a functional bulb doesn't it?

He said the "Hb" (high-beam) still works.

 

[Larry Fine]

I think that the indicator wire also has a spur goes to the 9 pin connector on the left hand side of the headstock - to which a quartet harness might be connected.

The 1100s don't have a quartet-harness connector, only the 1300s do.

 

[StuartKeith]

Ok with bulb plugged into fuse it's on full constantly. I've removed the tank again and rear lights as well