single dim headlight

[Aravind Dileepan]

I have an FJ62 with a FJ60 front clip. The previous owner did that swap.

Last week, one of the headlights died so I ordered Hella H4 replacements along with SLCFJ62's harness.

I replaced the bulbs first, and the driver side bulb was dim while the passenger side was regular brightness. On high beam, the driver side but out altogether while the passenger side went to regular high beam.

SLC's harness is not the issue or the simple solution.

When the problem is a "bad ground," how to determine that's the problem and how do you go about fixing it?

Thanks,

Ara

 

[DFXR]

I had a similar situation recently with my FJ60. Which side does the SLC harness plug into for it's "trigger?" On the 60 it is the PS, not sure about your modified 62.

I had a burnt PS bulb, then a dim PS bulb after I replaced both with H4s. I upgraded to the IPF headlight loom (similar to your new harness). But since the IPF loom connects to the PS headlight plug to get it's "trigger", it didn't work right. Most likely corrosion/resistance somewhere upstream in the old stock wiring, on the PS side, which was making that bulb dim.

My solution was to connect the IPF loom to the DS plug instead, since that was known good. This means reaching across the engine bay (since the battery is on the PS side on a 60). I didn't want to hack into the new loom, so I made a roughly 5' long extension with 2 H4 plugs, 3 lengths of wire, and hi-temp split loom to protect it. Maybe $20 in parts and it works great.

Hope this helps-

 

[Output Shaft]

Yeah, the purpose of theses headlight harnesses is to move the high amp draw of the headlights out of the stock wiring loom and switch and offload it into the new wiring harness via relays instead.

The only current that will be flowing through the new HL wiring harness to turn on the bulbs is a few mA to flip the relays. The relays then take the brunt of the current draw to power the lights via a direct connection to the battery.

If you plugged new bulbs into the new wiring harness and got a dim bulb on one side, the issue is likely poor contact with the bulb or a bad bulb.
The relays are either on or off, so you would get light or nothing. Not dim.

My guess it was a bad bulb. Buy two cheap 55w bulbs and try again. If they work, you were just unlucky.

 

[Aravind Dileepan]

Clarification: the single dim bulb is on the old harness. The new harness is nonfunctional due to 62/60 wiring discrepancies that I'm still sorting out.

In the meanwhile, I need to figure out he dim bulb thing. The reason I'm extra concerned is that it sounds like I'm getting less/weaker juice to the starter when I turn the ignition. And all this only after I started playing around with the headlights. In fact, yesterday I had to jump start even though I'd been driving for the past 45 minutes.

 

[RockDoc]

Are you taking in to account the different pin out for seal beam and H4 bulbs? In your troubleshooting, are you aware that the cruisers use switched ground rather than switched positive? These may be unrelated to the cause of your issue, but are important when you are trying to understand things. The pin out issue caused me some confusion (along with mistakes in the provided instructions) when I built and troubleshot a harness made from a Daniel Stern kit.

 

[Output Shaft]

Yeah, now I'm not seeing how this could be plug and play. A 62 harness won't plug n play w single 60 lights, and a 60 harness won't plug n play w dual 62 bulbs.

 

[Aravind Dileepan]

One of the things SLC is helping me with is identifying exactly what the previous owner did to allow the FJ62 wiring harness to power and control the 60 lights. So with his harness, we're moving pins around.

But I still think that's a separate issue from the dim bulb, because with the harness that came with the car, only the passenger light is working properly now (it all worked fine until one of the bulbs died two weeks ago - and I think it was the driver side). And I just can't imagine that my little bit of fiddling caused a ground-out that is draining the system and causing a bulb to burn dim.

 

[Aravind Dileepan]

Ok, I figured everything out:

1. As to the dim headlight: it was a blown fuse. When the original sealed beam headlight died, it took the fuse out with it. I think Toyota included a safety feature where if the headlight fuse is blown, a lower voltage still passes to the headlight, to keep them minimally lit. Lesson: if you replace a dead headlight, check the fuses (to the left of the steering column on left hand drive cars); If you have a dim headlight, check the fuses.

I figured this out because I used my volt meter to determine that instead of getting a full 12v at the headlight, I was only getting about 4. Meanwhile, the passenger side was getting the full 12v (and burning at full strength).

2. As to SLC's upgraded wiring harness, that was easy and SLC knew the issue right off the bat. I simply had to swap around a couple of leads on the connector that runs to the switch. The reason for this is that 60s are wired common hot and 62s are wired common ground. Since a previous owner swapped mine from a 62 front clip to a 60, I didn't know if they'd made any changes to the harness to make it functional. I simply knew that the headlights worked.

Well, now I know that the previous owner did change around the leads in the factory harness to match a 60 harness. Once I swapped those leads, everything on the new harness functioned properly.

Now only two things remain:

a. aim the headlights
b. figure out why my blue hi beam dash indicator doesn't work.

Thanks for the help.

Ara

 

[CSteppe82]

Ok, I figured everything out:

1. As to the dim headlight: it was a blown fuse. When the original sealed beam headlight died, it took the fuse out with it. I think Toyota included a safety feature where if the headlight fuse is blown, a lower voltage still passes to the headlight, to keep them minimally lit. Lesson: if you replace a dead headlight, check the fuses (to the left of the steering column on left hand drive cars); If you have a dim headlight, check the fuses.

I figured this out because I used my volt meter to determine that instead of getting a full 12v at the headlight, I was only getting about 4. Meanwhile, the passenger side was getting the full 12v (and burning at full strength).

2. As to SLC's upgraded wiring harness, that was easy and SLC knew the issue right off the bat. I simply had to swap around a couple of leads on the connector that runs to the switch. The reason for this is that 60s are wired common hot and 62s are wired common ground. Since a previous owner swapped mine from a 62 front clip to a 60, I didn't know if they'd made any changes to the harness to make it functional. I simply knew that the headlights worked.

Well, now I know that the previous owner did change around the leads in the factory harness to match a 60 harness. Once I swapped those leads, everything on the new harness functioned properly.

Now only two things remain:

a. aim the headlights
b. figure out why my blue hi beam dash indicator doesn't work.

Thanks for the help.

Ara

Did you ever figure out why the high beam indicator won't come on? I am having the same issue on my 62 with the new ipf harness

 

[Aravind Dileepan]

No, I haven't. I verified that the bulb is good, so it must be the way that switch is wired. They changed it from the 60 to the 62, and I think mine initially got messed up when the previous owner replaced the 62 headlights with ones from a 60.

I know it's an "easy" fix, to get the dash lamp working, but I don't know what it is.

SLCFJ62 is pretty good about answering questions and helping troubleshoot over email.