73 hack job reversal.

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Sep 13, 2015
midwest (iowa)
Finally time to install the wire harness. It is a 73. The PO bypassed the headlight switch and installed a toggle switch. I assume he was too cheap to buy a new switch. Regardless, the toggle switch has to go. I will attach a picture of his switch and the wiring on the harness. Anyone familiar with the wire orientation?
While I’ve got you 73 owners attention, I want to install a rear heater, but the truck I’m restoring did not come with a rear heater option on the wire harness. Considering options. Thank you in advance…


Sep 20, 2022
35th parallel north
It looks like a 4-wire switch, green, green, red, red/white?

So, it was by-passing the dimmer switch, keeping it permanently on low-beams?

@ToyotaMatt There are more than four spade connections on that connector?

Many of us are installing new headlight circuits for improved performance over the old configuration in the wiring loom. Relays, and heavier wire, fresh lamp connector, upgraded with or without factory switch. My harness is fine on my 40 for headlamps, other rig benefited from a new headlamp circuit (but deleting factory relays - bad/wet old relay switch). Those toggle switches are neat, but their quality is not. Nothing to shame a previous owner about, usually most people go with the time, skills, and material resources that are available.

I cleaned up a turn signal headlight dimmer switch before. On the bench, with a towel, good light, patience. The handle is partly broken, but the contacts are fresh - backup / loaner stash.
Apr 17, 2021
Calgary, Alberta
Toyota makes a upgrade Headlight kit that @Grayscale may be referencing. I purchased mine directly from Toyota however if you search there are lots of people selling the kit.

Welcome to the '73 club. I have a rear heater in my truck that was installed in by the PO. The '73 was the first FJ40 with separate front and rear heater switches. Below is the wiring diagram that I have that I have been using for my truck. Not sure if it helps. @Coolerman may be able to help with the wiring harness question.

Last edited:
Jan 5, 2017
Charlotte, NC & Alexandria, VA
FWIW, you'll likely not get a response from @Coolerman but you can get a lot of his help from his website.

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