Electrical problem with running / tail light

[OpFlash]

Ok had the xj 1100 out today and didnt realize till the evening that the running light for the brake light was not working. I checked the bulbs and the fillaments do not appear burnt. The lights work when the brakes are applied. I checked the fuses and they do not appear blown. I dont know if the front or rear turning signals are meant to be running lights. However I was screwing around with trying to get the horns to work and tried running wires from the battery to the horn terminals. I initially forgot to disconnect the horns wires and noticed that the dash lights flickered and there were some minor sparks at the terminals. It was after this that i actually noticed the running light problem. however i dont ever remember the running lights working even before i was messing around trying to get the horn to work. I then later noticed after turning the bike on and off a few times that the front signals were working as running lights. rear signals were off. turn signals are still working properly and hazzard lights work too. when the front signals were lit as running lights the rear brake running light was working. Then they would go off I noticed at times they would turn on again when i would crack the throttle a bit. Sorry for the long post just trying to explain situation any ideas thanks.

[Jerry]

Front turn lights are also running lights; they should have a dual-filament bulb in them. Rear are turn lights only, single filament. Different problems if none will light up.

For running lights, one of the 10 amp fuses is bad, or wires on either side of the fuse are bad. Pull the bulbs and hook a battery charger black (ground or -) to the case, then touch red (positive or +) to each of the bottom contacts in turn. If both filaments light up, bulb is good and you are not getting power to the front lights.

Try same procedure with rear bulbs, only there sill be only 1 contact to test.

Quite often the problems with front or rear is a bad ground connection Check all the ground wires, back ground is under the nuts that hold the turn signal stalk in place, in front you need to remove the headlight and track the wires that way. If I remember correctly the ground is black, but I can't check a manual so someone else might have to chip in. also clean the sockets the bulbs fit into, not uncommon to have a bad ground in the turn signal assembly. One bad ground will affect either system.

[OpFlash]

the front and rear turn signals are working correctly and light up just fine. its the running lights in the front /rear that are the major issue at the moment. They appear to light intermittently and seem to come on at times when the throttle is applied. This is not something that works all the time I just noticed this tonight. I will however say that his bike has been in storage for nearly 20 years and up unitl a week ago was finally back on the road so maybe some contacts do need to be cleaned. The fuses look ok but i know that they are old. what type of fuse is it and do you know the wattage of it.

[skids]

If the rear runners on the xj are 1157 bulbs and the brake lights work, your ground is probably not the problem for the runners when considering they share the same ground.

[Jerry]

its the running lights in the front /rear that are the major issue at the moment.

I've had a problem with 3 or 4 different bulbs that caused nearly the same problem, in one case kept blowing fuses. One of the filaments would break and touch the other filament causing erratic operation or no operation. Returning from Revelstoke last year I had both front bulbs go bad about the same time this way, found the fault by visual inspection. Also had a tail light bulb do the same thing last summer, one bad bulb and neither would come on when brakes were applied.

I sought out and now carry and use 'heavy duty' 1156 and 1157 bulbs.

I would buy a cheap 12v test light - $3 to $4 at most auto parts stores, and check for voltage at the sockets. Your front sockets will have 3 wires coming out of them; ground, turn, and running light. If the turn signals work then the ground is not the problem; either you have no or intermittent power to the socket (wiring / connection problem), the bulb is bad, or there is a problem with the contact in the socket or on the bottom of the bulb. If you do have voltage, replace the bulbs. Both of them.

My recollection is that the rear circuit does have a different ground than the front; there should be connectors under the XJ seat for ground, running, brake, left turn, and right turn functions. Clean all these connections. (You can also use the test light at these connections to test for voltage if you do not feel like pulling off the lenses and pulling the bulbs, or to determine if there is a break between these points and the rear bulb sockets.)

In short, the testing is not difficult but it may take a little time. If you have the OEM fuse block note that the 'fingers' are notorious for corroding and even if the fuse is good you will not get power into the wiring. I would strongly suggest you do a search for fuse block replacment and swap in a new block. The OEM unit is always suspect when it comes to trouble-shooting electrical gremlins.

[OpFlash]

Hey guys did some more checking today and started with the fuses initially i did a simple visual inspection and noticed that they were not blown. well i actually looked a little closer and noticed that the 10amp fuse for brake or light was not making good contact. I thought that the holder for the fuse or "finger?" was spread apart too much but i noticed that it was cracked / broken i was able to kinda put them together to make a tighter fit and then turned the key to the on position and the running lights in both the front signals and rear brake were working. so i know that the holder for the fuse needs to be replaced. went to the auto parts store but couldnt find it any idea where i can locate those things?

[Ken Talbot]

Check out the farticles in the modifications section - electrical. You'll find a few ideas. Direct link here

[randy]

You might as well replace the whole fuse box with blade-type fuses like this. Contact T.C. , he'll hook you up!