headlight issue

[navigator]

I was driving home the other night and my headlights started flashing really bad, off and on, off and on.

 

i also noticed the interior lights are also flashing as well.

it doesn't do it when I initially turn the lights on, only when they have been on a few seconds does it start.

 

i figure it is a ground somewhere but thought i would ask here before I start chasing wiring problems.

 

bTW, i recently wired up a CB by finding a 4 wire plug under the dash that was hot and used two male electrical blade type plugs to plug into that plug, could that be related?

[LoTGoD]

Without knowing much about how that hot lead is wired, I'd say start there and remove the newly added connectors and see if the problem goes away. If it does, you need to see where those "found" wires go. Was the CB on when all of this was happening with the lights? Sounds like what you might have thought was a ground wire in that bunch of 4 wires was not a ground. Remove it and let us know if the problem goes away.

[navigator]

the CB was off.

I have used the CB some for a couple of days and it seemed fine (during the day).

While troubleshooting, i noticed the interior lights blinking as well. I turned hte CB on and it is "flashing" as well.

 

i'll try pulling those wires this afternoon and see what happens.

[Geonovast]

Does the CB have its own ground? Or did that get plugged into the connector?

[navigator]

I plugged it into the connector.

i found the plug and got 12v from a red wire and a black wire and figured it would work.

I'll try to unplug it this afternoon and see what happens.

 

I'll be traveling tomorrow so I might not respond immediately.

[Eagle]

The headlight switch incorporates a built-in circuit breaker. When it goes bad, the headlights create enough draw to trip the breaker. As soon as things cool off, the lights come back on ... until the circuit breaker overheats again.

 

How long will the lights stay on if you just turn on the parking lights? Is the interval shorter using the high beams than it is with the low beams? (High beams draw more current, so if the breaker is weak they'll overheat and trip it faster than the low beams.)

[navigator]

it was my ghetto wiring. I unplugged the CB and all is well.

The plug had 4 wired, red with white stripe, black, brown with black stripe and white with black stripe.

 

instead of getting the red and black wires, I had the red and brown wires.

i switched to red and black and everything is fine now.

 

funny thing is when testing with the meter it seemed as if all were grounds except the red wire.

anyway, thx for the responses.

[Randy in Maine]

Eagle,

 

I am bringing up a post from the dead if that is OK

 

I noticed tonight coming home in a light snow, that my headlights are doing the same flashing thing.

 

I intend to pick up this switch tomorrow and install it. Do these thing have relays for the headlights also? Is the Echlin switch any good? I could try try the dealer if theirs is any better.

 

http://www.napaonline.com/Search/Detail ... 006+101990

[Eagle]

bTW, i recently wired up a CB by finding a 4 wire plug under the dash that was hot and used two male electrical blade type plugs to plug into that plug, could that be related?

Bad move.

 

NEVER connect anything to a plug if you don't know what it does.

 

You may have wired into a plug for the optional fog lights. The headlights have a circuit breaker built into the switch, so it sounds to me like something about your CB install created either an overload or, more likely, a short that's tripping the circuit breaker. Unplug the radio from that connector and see if things go back to normal.

[HOrnbrod]

I intend to pick up this switch tomorrow and install it. Do these thing have relays for the headlights also? Is the Echlin switch any good? I could try try the dealer if theirs is any better.

 

No, the factory headlights do not have relays. The optional foglights do though. :nuts: The Echlin switch should work fine if that's the problem, but I like the OEM stuff better. P/n 56001861, about $25 at the stealer.

[Randy in Maine]

The Echlin switch should work fine if that's the problem,

 

Excellent point.

 

If the circuit breaker in the switch is really just doing it's job here and overheating when something is indeed shorting out downstream of the switch, how would you suggest troubleshooting the electrical problem? Any likely suspects?

 

The only things that do not work on this Jeep (and have not for some time) are the dual interior "dome lights" up in the pillars with the funky rocker on off switches. If those are running though this breaker, would I be well advised to start lookng there?

 

Both headlights work in both high and low beam, and the dash lights/taillights/signals/marker lights/license plate lights all work OK.

 

Thanks in advance!!

[Eagle]

The built-in circuit breaker can just get tired. It's rare -- I have multiple 20+ year old XJs and MJs that don't have any problem, but my 1978 full-size Cherokee had the light switch go bad when it was only about 12 years old. First it would only trip when I had the brights on. Then even the low beams would trip it, so I had to replace it.

[Randy in Maine]

Thanks!

 

That is my plan (to replace the light switch) first and see what changes. Hopefully that will fix the problem. I will keep you posted.

[HOrnbrod]

I would try first making sure all the mains cables are tight and corrosion free, then unplugging one headlamp at a time just to see if if it can be isolated. But I think it's the switch too.........

[Randy in Maine]

Quick update.

 

The new headlight switch did not fix the problem and I ended up taking it to "my guy". 5º here this morning and I had a meeting I could not get out of.

 

One of the headlight power lead wires had rubbed itself raw and was shorting out. The circuit breaker in the switch was doing its job.

 

I picked it up after they had closed so I could not talk to the mechanic who fixed it to find out more information.