Headlight harness upgrade poll

Headlight wire harness poll

  • My wiring is fine or I already have a new harness

    Votes: 17 21.0%
  • I want plug and play. I am OK with HI/LO fusing

    Votes: 40 49.4%
  • I don't mind running a wire for the safer fusing

    Votes: 10 12.3%
  • We already have enough wiring options

    Votes: 14 17.3%

  • Total voters
    81

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Joined
Oct 29, 2008
Threads
105
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2,447
Location
In the valley of the Great Salt Lake.
Hello the 40/55 forum. After talking to a few FJ40 owners, it is apparent that Toyota didn't do any better job with your headlight wiring than with the wiring in the FJ60 and FJ62s--in fact, yours is probably worse. If your headlights are yellow and dim, you know what I am talking about. I have been building headlight harnesses for FJ60s and FJ62s to either make the stock sealed beam headlights much brighter, or enable the use of higher wattage H4 upgrade headlights. I am planning on also building a harness for the FJ40.

The stock FJ40 wiring has one fuse for all the headlights. So if the fuse blows, you will be driving in the dark. I can build a harness (see schematic below) that is plug and play that has separate fuses for the HI and LO Beams. So if one of the headlight fuses blow, you would still have either HI or LO beam, which is an increase in the safety margin over stock. I could also build a harness that is fused right and left side, so if a fuse blows, you will still have HI and LO beam, but only on one side. This is the safest configuration, but would not quite be plug and play. It would require one wire to be connected to the headlight switch or the HI/LO Beam switch, whichever is more convenient.

So my poll is to see which option you would prefer. I realize that you also have other wiring options, but my harnesses are unique in that they can also come with additional capability to control other Auxiliary circuits like fog lights, driving lights, etc that will reduce fuse and relay sprawl in your engine compartment. (See my sig line)

You could also build you own harness from my schematic if you like.
fj40schematicweb.webp
 
Fuse Hi beam/ Lo beam separately makes the most sense to me. Prefer to have lights on both sides, less likely to get stopped. When will your 40 harnesses be available? Price?
 
How would this compare to the ARB/IPF M002 harness with three relays?
 
I've never touched an IPF harness and can't find any specs such as wire size, etc. The M002 seems to be generic. ARB USA lists 21 vehicle makes that it fits. I'm sure it is a fine wire harness. Do you have one installed in your rig?

My harnesses are built with 12 gauge wire, ceramic high temp headlight connectors, and mesh wire armor. They are built for a specific vehicle so all the wires are the correct length. My Ultimate Harness is weather tight, and in addition to the headlights, also includes extra relays for additional driving lights, fog lights, etc. You can see my sig line for links to the harnesses that I build for FJ60s and FJ62s. Would be similar for FJ40s but the Standard harness would be a little cheaper (only need 2 relays) and the Ultimate harness would have 3 Aux relays.

But for now, I just wanted to do the poll. So far, it looks like most folks like plug and play. It's the same over on the FJ60 forum. Wiring and electrical issues seem to be the least favorite thing to do.

How would this compare to the ARB/IPF M002 harness with three relays?
 
I'll buy a high/low plug 'n play as long as the price is not stratospheric.
 
Yep, trying the ARB/IPF unit now on a 45. Heavy-gauge wire as you have, but, of course, not ceramic plug ends, so I will change that out later.

But I questioned their use of hard-to-find relays, especially the need for the 3rd or "switching" relay.
The wiring seems unnecessarily fussy, but I have heard about Toyota's use of grounded headlite circuits and the need for some feedback within the circuits to power the hibeam dashlite.

ARB/IPF also has two taped connectors they instruct ALL Toyota owners to snap together, although mine worked both connected and disconnected. I asked ARB Seattle about this, and their explanation is kinda fuzzy. I realize a universal unit such as theirs has to accommodate a lot of manufacturers, but I have seen three-relay looms before and wonder about their purpose.

I have also read about de-spiking(clamping) relays with an internal diode to prevent reverse polarity High-voltage spikes on shutdown. Are these worthwhile and needed?

I prefer a simpler, but effective headlite loom, but don't want to lose any protective features they may be offering. And it appears I cannot simply replace their relays with quality relays from another source.

Thanx.
 
Yep, trying the ARB/IPF unit now on a 45. Heavy-gauge wire as you have, but, of course, not ceramic plug ends, so I will change that out later.

But I questioned their use of hard-to-find relays, especially the need for the 3rd or "switching" relay.
The wiring seems unnecessarily fussy, but I have heard about Toyota's use of grounded headlite circuits and the need for some feedback within the circuits to power the hibeam dashlite.

ARB/IPF also has two taped connectors they instruct ALL Toyota owners to snap together, although mine worked both connected and disconnected. I asked ARB Seattle about this, and their explanation is kinda fuzzy. I realize a universal unit such as theirs has to accommodate a lot of manufacturers, but I have seen three-relay looms before and wonder about their purpose.

I have also read about de-spiking(clamping) relays with an internal diode to prevent reverse polarity High-voltage spikes on shutdown. Are these worthwhile and needed?

I prefer a simpler, but effective headlite loom, but don't want to lose any protective features they may be offering. And it appears I cannot simply replace their relays with quality relays from another source.

Thanx.

The headlight diagrams I have seen for the FJ40 (1969 the oldest and 1981 the newest) all have switched 12 volts to the headlights, and NOT switched ground like the FJ60 and FJ62 have. Consequently, the FJ40 does not have the issue with feeding back the Hi Beam signal for the Hi Beam Dash Indicator. The Hi Beam Indicator gets its 12 volts directly from the Hi Beam switch, and the dash indicator will come on even if you have no headlights plugged in. So in that regard, the FJ40 is not a special case, and overall is a simpler harness than later model Landcruisers. I can't speak for the IPF harness, but with the harness I have designed for the FJ40 I only used two relays--one for the high beam and one for the low beam.

When you switch off a relay, the collapsing field around the coil can induce a small electrical spike. This could be an issue in a sensitive device, but I don't believe it is an issue in a vehicle. The expanding and collapsing field in and around the ignition coil is going to be an order of magnitude larger than any puny spike coming from a collapsing relay coil, so in my opinion clamping diodes in a headlight harness are unnecessary.
 
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I would get a plug and play one when/if they're available
 
i installed inline fuses at the headlights and never had a problem.if the relays fail do they fail closed ?
 
I wouldn't mind someone. Plus if it makes plugging in aux. lights easier that just make everything better.
 
Put me on the list as interested.

I have been thinking of staring @ the Slee harness I installed on the '80 till I understood how to build my own for the 40.

But plug & play would be nice if the price is right.

Make sure the relays can be positioned high & dry.
 
I will also be in the market for an upgraded harness... hi/lo, plug and play
 
I installed relays and Silverstars - OEM switch goes hi/lo - never had a problem :meh:

people in front of me tell me it's damn bright :meh:
 
If I built my own harness, I was thinking of putting the relays on the fire wall. Probably over kill, and would involve a lot more wire that necessary or practical, but as an electrical idiot, I grant myself some leeway.

I guess most of the electrical issues I have seen from water crossings have been ignition related, not sure if headlight circuits really should be that big of a concern. I guess "headlights going under" are just my personal reference point.

May be an interesting poll question to see what other electrical issues folks have experienced from water crossings. See what the "low point" is in the electrical system.
 
As long as you use sufficiently large load carrying wires--12 Gauge--there should be no problem mounting your relays on the firewall. All my harnesses go across the firewall to get to the headlight on the other side for ease of installation. Most relays themselves are typically sealed, but the connector they plug into is not. Of course, the headlight connectors are not sealed either....
 
I like the plug and play but I want a heavy wire going to the battery to get the full amperage of the battery going to my headlights. I run the Hella h4 conversion headlights and at low rpms they are dim. They really get bright at operating rpms. I have thought about doing it myself but I really dont know enough about wire thickness versus load carrying amperage. Anything will be an improvemant to the factory harness. All of my add ons I have run through relays and outside of my existing harness except my headlights. I try to keep the amps down on that old wiring. Very interested in your product. I have priced the name brands and I think that they are too much $$$, although I don't mind paying for a good product if it is very high quality.
 

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