The outers in a quad headlight system are usually hi/lo. If you replaced the outer sealed beam with an h4 the stock harness should work fine and should be the same connector configuration. That's been me experience with older saabs and volvos and volkswagens.
So here is what I would do if someone handed me an FJ62 and asked me to help put in new H4 lights. First of all here is the standard pin configuration of an H4 bulb which you will be running in your H4 housing:
Now, does the stock connector look like this?:
if it does then life is easy and all you need is a voltmeter.
1. with the truck 100% off switch the voltmeter to read continuity (usually a little musical note symbol or sound wave symbol which will beep when the two leads are touched together)
2. Stick one pin of the meter into a connector and the other pin to the battery ground and see if it beeps. Only one connector should beep...when you find that connector you have found the ground or common terminal and make sure it matches the bulb shown above.
3. Now turn on the truck and switch on the low beams.
4. switch the voltmeter to read DC voltage or switch to the 20v DC scale.
5. stick one pin of the voltmeter into either of the non ground pins and place the other pin on battery ground
6. look for battery voltage (12v or 24v) depending on your system)
7. When you see voltage you now know which terminal is the low power terminal.
8. If this matches your H4 bulb then just plug it in and you are all set.
9. alternatively if the ground terminals match you could just plug in the connector and turn on the low beams..if the high beams come on then you know that the low and high terminals need to be switched.
10. two ways to switch the terminals
11. preferred way is to pop the spade terminal out of the plastic housing connector and switch to other position as this way does not damage the integrity of the old wiring
12. alternative way is to cut the high and low beam wires (truck off) and splice them back together but routed correctly.
13. Lastly if the HJ61 harness has 3 wires going to it but has some strange shape or does not have spade type connectors then you will have to cut off the old connector and splice in the H4 style connector and you will still have to identify the hi/lo/ground wires as described above.
simple video discussing how to pop connectors out of a housing:
