Dim Headlight Question

[Michael.lee]

On my 84 60 {Named Clifford- the Big Red Truck} I have been experiencing an issue with my headlight.

Inititally both lights wouldn't always come on- high beams worked, but no low beams. Found out the previous owner had out a new wiring harness in and the old one was still there. After failing to determine why the new harness wasn't working, I just switched back to the original harness and everything seems to work fine... including my high-beam indicator- for the first time.

But- sometimes my driver side headline will go dim- while I am driving. Then, for seemingly no reason, it will brighten up again.

The other night I pulled into my garage- and the light was dim, I gave it a nice solid tap with my knuckles and it brightened right up.

Any thoughts? Do I need to clean the connectors?

I am a bit of a novice working under the hood, but I am not afraid to get in there and learn.

Thanks-

84 FJ60 AKA Clifford

 

[RockDoc]

So you rapped on the headlight, and it brightened up again? My first guess would be filament in the bulb is loose. Try replacing the bulb, or switching the 2 to see if the problem follows the bulb or the wiring.

The harness that was added was likely to help with light output. The factory harnesses are notorious for undersize wiring and voltage drop. See the link in my signiture line for a bit more on that. Did you see any relays in the added wiring harness? Maybe one has given up the ghost.

 

[Michael.lee]

There were relays. The previous owner helped me a bit via email- Had me check some inline fuses, and the relays- the funny thing is that the lights would sometimes work on the New harness- sometimes not. At least with the old one, they always come on.

I'll try swapping the bulbs and let you know. If I end up replacing, should I do both at the same time?

One of these days, I am going to try to figure the newer harness out, since it certainly pumped out a lot more light. If the filimant is loose, could that have had any effect on the newer harness?

 

[rchalmers3]

You may find a poor ground connection is your source for intermittant problems like you have described. If swapping the bulbs dosen't solve the problem, do an investigation of the ground path. Loosening and reconnecting ground terminals often solves these niggling little problems that surface on older trucks.

Rick

 

[RockDoc]

If you end up replacing them, do both, so they are balanced. When you are checking and cleaning contacts, it would be a good idea to coat them with dielectric grease when you put them back together, to help avoid future problems.

 

[Michael.lee]

Ok- so I swapped the lights last night- and so far so good. I'll keep an eye on it tonight when I drive home.

While I had the light housing off, I started checking the newer wiring harness that had stopped working with the lowbeams. I tried swapping the plugs into the two relays for the new harness, checked the conncetions, gounds, etc... but the same problem is still there- low beams don't work, high beams do.

Eventually I'd love to be able to use the newer harness- since it draws straight from the battery and produces way more light. Any suggestions for next steps on diagnosing the problem with the new harness? (I am still using the original harness, since that works fine, assuming the dimming problem is fixed.)

 

[RockDoc]

If I read the original post correctly, the upgraded harness would intermittently work properly, then the low-beam started to act up and eventually never worked? Or did the low beams never work right?

If it was the former, I would think the fault lies in either a bad relay, or contact or wiring connection that has gone bad. If the latter, I would suspect the layout for the wiring was faulty from the start. Would you be able to pull the harness out and have a good look over it somewhere comfortable? There are a few threads floating around in the 60s section with wiring diagrams. A look over them may help you out. Search "headlight harness" and you should find them.

 

[Phrog]

Occasional flickering/dimming suggests a bad ground. If you
haven't already done so, check/clean/retighten all connections.

-Phrog

 

[RockDoc]

Maybe the source of your trouble with the stock harness shows up in the upgraded harness as a lost signal to the relays, and is responsible for that too. Was the triggering for the upgraded harness taken off the same side that was acting up with the stock harness?

 

[Michael.lee]

Nope- the Driver's side light was the one going dim. I swapped the lights and cleaned the connections, and that seems to have done the trick for the dimming problem on the stock harness.

The After Market harness plugs into the passenger side stock harness. It powers off the battery- I checked the grounds for the after market harness and they seem fine. The PO suggested I start at the battery and work my way down the line, checking and cleaning every connection. There are two inline fuses that look fine, but I am going to go ahead a replace anyway.

I tried swapping the plugs into the two relays- and the high beams still work and the low beams don't.

I'll keep you posted as I tinker.

FYI: The original problem with the after market harness was that the low beams wouldn't come on right away, but sometimes would come on after a few minutes. The first time it happened, I turned the lights off and on a few times and that did the trick. The second time, I ended up having to drive home with my high-beams on- and about 15 minutes into the drive I flipped over to low beams to check, and they were on... got home, and ended up having to run out to the store a few minutes later and the lights came back on. The next time it happened after that it was stock harness time.

 

[Michael.lee]

I solved the problem. As suggested, I cleaned all connections and coated them with dialectic grease, and I replaced the inline fuses... and voila! The after market harness is back in business.

Next step: Four eyes of fury... maybe. Any suggestions on adding driving lights?

 

[RockDoc]

Good to hear. I can't offer any real advice tonight as I am righnly pissed after a good night of karaoke. Maybe in the morning I can say something of use. (but then, I haven't messed with extra lights beyond the upgrade of the stock headlightlocatinos.) Maybe a new thread to capture the intrest of folk with driving lights who have looked over this thread and didn't have anyting to say?.

Iron Maiden rocks!

 

[grant5127]

Most all driving light kits of any quality have switch, relay and wiring included......

 

[Michael.lee]

We got a mess of snow overnight, and boy howdy was it nice to have the after market harness working again. I could actually see what I was running over.