C27 connector looks to be interior lighting feeds, exterior and headlamps..?

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Well, the first sign of something going wrong (other than the smell of something burning/smoldering) was the dome light flickering and going out.

I've got a few decades of experience with British cars, going back to childhood. I know exactly what "I smell something burning" and "Hey, that part of the electrical system just flickered and went offline" means. It means "Disconnect your battery and shut down your electrical system *now* because you're about to have an electrical fire if you don't already."


(Not my car, not my pic, just using as an example.)

Generally the rule with British cars is that once you've got everything safed and you've waited to see if something smoldering behind cover is going to burst into flames, the next step is to start tracing things back from the system you saw fail. The fact that the burning appears to around some diodes that are in the 4Runner's lighting circuit seems to make sense in this context.

Yes.. you been around... Dash flickering bad. I just seen oxidation in the dome overhead light due the same flickering. Only with standard bulbs though. Very interesting possibilities on the leds. As they would stop current flow in the opposite direction.

Still should have blown the fuse if it melted down. The cucuit amperage should have been exceeded and snapped that fuse open. Very odd indeed and as far as I know, hasn't been reported as happening before on this forum...:/

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The harness connector had some congealed smoke/fumes on it, but was undamaged.


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Checked out the wiring harness - with the instrument cluster removed, the wire read 0V as expected at both ends with a digital multimeter.


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After eliminating the harness as the source of the problem, I went to the burned gauge pod and found/confirmed with the DMM that the D24 diode had gone bad; it had decided to no longer be one way.


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Figured out why my spare cluster had display issues with the LCD odometer (loose cables) and swapped that in... after checking the D23, D24 and D25 diodes were still working with the DMM. Everything works again.


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I have a suspicion that we may see more of this as these trucks get older - I'll go pick up a couple more of these out of the junkyard, see about reworking them and keep them as spares.

Thanks for the update.. Glad you got it fixed.

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Glad you got it sorted. I saw you post in the local FB group looking for a replacement cluster. I'm curios if the 01/02 clusters use the same diodes back there.

Don't know, but apparently the connectors are different. The 2002 wiring info I had was different than the 2000.

If I see a 2002 in the junkyards (in cooler weather), I'll pull the gauge cluster out and see - it only takes a few minutes.

2000 dash will not be the same as a 2001 nor 2002. 1998 is different then 1996 and 1997. I would verify the dash are compatible.

I will keep my eye out for a 2000 dash for you. All i have here in my parts inventory is a 1998 dash auto. :-)