Low beam headlight issue (last resort)

[jrmcafee]

1998 SE 2.5L 5spd I’m bringing back from the dead. It’s got 83k on the clock and only 600 of it has been added in the past 10 years according to CARFAX. In other words, a barn find.

As expected, some electrical weirdness I’m sure due in part to dirt, dead leaves, and dead bugs. However I’ve replaced the dash switch, the column MFS, checked all interior and engine bay fuses, and cleaned the connectors at the lamps so I think I’m covering most of my bases.

I get high beams if I hold the turn signal toggle in, and if I roll the dash plunger all the way left I get dome lamp. Prior to replacing the dash switch I could wiggle the OE plunger and get a little life from the markers and brakes. After replacing the column switch I now have no issues at all getting hazards or turn signals.

Here’s what I’m left with: it’s either the harness connector to the dash switch has burnt terminals or something funky has been done with the aftermarket head unit or grille guard lamps.

Any other ideas before I break down and take this to a mechanic? Thanks for your help.

 

[AndyG]

@Jamison C is exceptional with TJ electrical..the @ sign notifies him, and he can give you an idea where to start.

My biggest concern with this type backstory is rats chewing wires.... although that may be far from the case.

Sitting kills 'em. You will have more to sort out before it's over, take it one thing at a time.

 

[jrmcafee]

@Jamison C is exceptional with TJ electrical..the @ sign notifies him, and he can give you an idea where to start.

My biggest concern with this type backstory is rats chewing wires.... although that may be far from the case.

Sitting kills 'em. You will have more to sort out before it's over, take it one thing at a time.

Thanks Andy, I'll take all the help I can get for sure. @Jamison C if you have ideas, I'd covet your feedback.

 

[AndyG]

Thanks Andy, I'll take all the help I can get for sure. @Jamison C if you have ideas, I'd covet your feedback.

He's really good to help out and he's got a factory service manual... In my limited knowledge the wiring on these is less straightforward than I thought it would be but my Jeep knowledge goes back to 1983-84-85 when a Jeep had about 1970 technology.

One thing that seems to be the case and I don't know all the details but most everything runs through the cluster if there's any kind of indicator light on the cluster....

Keep an eye on your grounds.

Definitely look for anything that's been chewed on.

It may not hurt to check the back of the cluster... There are videos on YouTube on how to pull it it's really not that complicated.

good luck man these guys typically follow up we just got you started pretty late last night

 

[Jerry Bransford]

Keep in mind that the low beams use a one-wire circuit with no relays involved. Follow the violet wire with the white tracer, it connects the headlight's low beams to the headlight switch. That violet/white wire runs from the switch to the driver's side then to the passenger side headlight. The headlights receive their grounds via the short black wire that connects from the headlight connector to the tub.

 

[Jamison C]

I would start with what Jerry says. Power goes directly through the switch to the headlights, all though a 16g wire which IMO is a bit of a design flaw. But if you bought a cheap headlight switch that could also be the issue.

 

[jrmcafee]

I would start with what Jerry says. Power goes directly through the switch to the headlights, all though a 16g wire which IMO is a bit of a design flaw. But if you bought a cheap headlight switch that could also be the issue.

Can you say more about the “cheap headlight switch”? Because I simply bought what I assumed was an OE replacement from Autozone. The original one had rusted entirely through but I at least got a little play if I fiddled with it, which makes me think I don’t have a wiring issue.

The Dorman “HELP!” plunger I bought to go with it fits snugly but doesn’t lock into place and while it will fire the dome lamp if I go full counterclockwise, it does nothing for the dimmer or the exterior lights. Is there a better alternative for the dash switch and plunger?

 

[Jerry Bransford]

OE replacement does not mean it's the OEM part, it just means it will fit.. not that it's what the factory installed.

Autozone's house brand is Duralast... the cheapest of the cheap and least reliable. I might buy Duralast air freshener or floor mats but never an important critical part.

 

[jrmcafee]

OE replacement does not mean it's the OEM part, it just means it will fit.. not that it's what the factory installed.

Autozone's house brand is Duralast... the cheapest of the cheap and least reliable. I might buy Duralast air freshener or floor mats but never an important critical part.

That’s good to know. Any brands that we feel good about?

 

[jrmcafee]

Still working through process of elimination here. I’ve ordered replacement bulbs as the ones in the Jeep currently have a bit of overspray on them from when the vehicle was repainted. This means they’re at least a decade old.

However I’m getting high beams so I don’t really think it’s the bulbs. In any case I pulled the center dash cover this evening and removed the aftermarket head unit. Need some audio expert help here: based on the photo is there any possibility I should think the aftermarket radio is the culprit? The head unit works, by the way.

 

[Chris]

Looks like a typical stereo installation to me. I don't see anything immediately concerning.

 

[never monday]

Still working through process of elimination here. I’ve ordered replacement bulbs as the ones in the Jeep currently have a bit of overspray on them from when the vehicle was repainted. This means they’re at least a decade old.

However I’m getting high beams so I don’t really think it’s the bulbs.

High and low beam have separate circuits and filaments in the bulb. Still could be the low beam only is burned out

 

[jrmcafee]

High and low beam have separate circuits and filaments in the bulb. Still could be the low beam only is burned out

I have an order from Quadratec coming in tomorrow. New lamps, inner shift boot, and hopefully putting this dash and console back together. Driving at night would be a nice bonus.

 

[jrmcafee]

Update here: I replaced the bulbs with low-end sylvanias, to no avail. I now know how to navigate the inner and outer rings of the headlamp retainer and negotiate their removal with my grille guard though, so that’s a bonus.

I suppose I am now down to either the grille-mounted spotlights or faulty wiring as the culprit.

 

[Jerry Bransford]

Faulty wiring was already suggested last week. Again, there's just one wire between the switch and the low beams. Check above for the color of the wire.

 

[jrmcafee]

Closing the loop on this one. The issue was the dash dimmer switch. I ordered a salvage one from Dead Jeep and that did the trick. After comparing the eyelet screw that holds the switch in place and feeds the plunger with the one that’s original to the Jeep, I have a feeling that may have been what was shorting the original switch. It was rusted and the insulator in the sleeve looked worn and etched. I now have dash lights and low beams.

Now, on to removing the spotlights (and hopefully the grille guard as well).