Hi there – I have a 1977 US FJ that came with the 84112-60010 Switch Assembly. The current Factory 5pin harness side connector plug is intact and in good solid shape. The small RED and WHITE color coded wires feeding the little golg spring loaded twist bulb socket base that enters the rear of the 84112-60010 is as it came from the factory too. The twist bulb is burnt out so I have reordered a new one to see if it works. The issue that I have with my current switch is that the Cluster lights don’t work at all. I put a “generic” light switch in from Painless and was able to get the Cluster lights to work so I know they are good. I essentially mapped 4 tabs on from the Painless switch to TB - Fuse (tail) 15A, HB To Fuse (head), TL tail light, and PL to Pilot light (i believe this is the one that powers the cluster lights) - See attached picture for the connector mapping. I also checked all the bulbs in the cluster. I purchased a 84112-60020 4 prong light switch and was wondering if I someone could help me map the 4 prongs to the correct wires on the 5 prong harness to get everything to work, minus the Reostat. I tried plugging in the 4 prong to the existing harness and it doesn't fit. Silly me for assuming. I would guess if mapped correctly, this would simply mean that the cluster lights can’t dim or brighten because the new switch isn’t dimmable. The cluster lights would just come on or go off when pulling the light switch in and out. I am happy to take pictures or whatever is needed for help. Thanks in advance!
FJ 40 Headlight switch Question – Go from 5 Prong Reostat to 4 Prong Non-Dimmable
- Thread starter HawksFJ
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sadovnik
SILVER Star
Just get the pigtail/adapter from @Coolerman and be done. Part # HLSAN0 . Also, the light switch you bought doesn’t have a bulb socket so it won’t be backlit like on the 84112-60010 light switch. Did you check the tail light fuse? It’s the top fuse (15A). Dash lights are on that fuse.
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- #3
Thank you @sadovnik! I will certainly buy that adapter and make life easy. 
I was aware the light switch I bought doesn’t have a bulb socket so it won’t be backlit. I'll just pin mine up and out of the way. Thank you for ensuring I knew that and reply here.
I was aware the light switch I bought doesn’t have a bulb socket so it won’t be backlit. I'll just pin mine up and out of the way. Thank you for ensuring I knew that and reply here.
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- #4
@sadovnik I got the Part # HLSAN0 wiring harness recently, and it’s a really solid product that fits my vehicle perfectly. The install was easy, and everything worked great except for the dash lights, which won’t turn on when I pull out the light switch so that’s confusing to me. I purchased the Toyota OEM Switch 84112-60020, which features four prongs and is not dimmable. So, the expectation that I had when purchasing the wiring harness was that going from the 84112-60010 Switch to the 84112-60020 switch, the cluster lights would simply turn on or off when pulling out the light switch but they would not be dimmable.
Upon further trial and error. There is definitely something wrong with my original switch because the ReoStat doesn’t work, and the twist bulb wiring with the little spring doesn’t become “hot” with the old light switch plugged in. So, I am wondering if it’s a combination of a ground and the ReoStat. I know this because I wired in a Painless “generic” switch 80151 (LINK) and the cluster lights operate correctly, the twist bulb functioned/light up, and the ReoStat on the Painless switch is able to brighten and dim the lights on the dash. The current challenge I have with the Generic Painless switch is that the Dash lights remain on even when the lights switch is fully pushed in. I’ve turned the dash lights “off” with the ReoStat for the meantime. I plugged Head into HB – To Fuse Head 20A, Tail into TB – To Fuse (Tail) 15A, Dash (bottom left) into PL – TO meter Pilot light, Aux (top left) into TL – Tail light, and Bat (top right) into HD – To Dimmer switch.
I would appreciate any insights.
Upon further trial and error. There is definitely something wrong with my original switch because the ReoStat doesn’t work, and the twist bulb wiring with the little spring doesn’t become “hot” with the old light switch plugged in. So, I am wondering if it’s a combination of a ground and the ReoStat. I know this because I wired in a Painless “generic” switch 80151 (LINK) and the cluster lights operate correctly, the twist bulb functioned/light up, and the ReoStat on the Painless switch is able to brighten and dim the lights on the dash. The current challenge I have with the Generic Painless switch is that the Dash lights remain on even when the lights switch is fully pushed in. I’ve turned the dash lights “off” with the ReoStat for the meantime. I plugged Head into HB – To Fuse Head 20A, Tail into TB – To Fuse (Tail) 15A, Dash (bottom left) into PL – TO meter Pilot light, Aux (top left) into TL – Tail light, and Bat (top right) into HD – To Dimmer switch.
I would appreciate any insights.
- Thread starter
- #5
Just posting an update here that I’ve gotten the generic Painless 80151 Switch with ReoStat to work. I must not have had everything firmly plugged in earlier. Here is how I have the Painless 80151 Switch plugged in.
Painless AUX Goes to TL….To Tail Light
Painless Bat Goes to HD….To Dimmer Switch
Painless Tail Goes to TB…To fuse (tail) 15A (tail light power source)
Painless Head Goes to HB….To Fuse (head) 20A (Headlight power Source)
Painless Dash Goes to PL….To Meter Light
This setup enables the headlights, taillights, dash lights, and ReoStat to function correctly.