The doors don't do anything currently. I'm trying to figure out why the light is so dim, and why it runs off when I plug in my radio and the dash. Specifically plug D, pin 12 for that is labeled DOME fuse. So something is drawing lots of power but I cant pinpoint what is. Anyone have an idea?

You have the wiring for your year correct? I don’t know if what I posted is accurate for your 2000


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The 4Runner is actually a 99, I need to update my signature.

sorry to rehash. if you remove the dome light itself from the socket and hook it up to a separate 12v source, it glows brightly, as one would expect? have you switched out and put another bulb in its place, even temporarily with a wire lead if it's too small? if you don't have an extra handy, you could rob the vanity mirror light, for instance. are the connector prongs for the light clean with no corrosion?

with the vehicle off, what amperage do you read on your DVM, and the light is on but running dim? check in series with the light, then with no light, then with the light in place and in series with your battery negative and your battery negative cable. see the useful parasitic battery drain instructions that others (recently @LittleCaesar on this thread ) have linked to on similar troubleshooting threads.

another thing to try, for grins, is to unplug fuses you *know* aren't involved with the dome light, and see if the dome light brightens. if i read your recent post properly, the light dims when you plug in (i assume you're meaning turn on) the radio. if the radio is not plugged in / turned on, the light is bright and ok? if that sounds accurate, then it's possible that your radio simply is drawing a *lot* of power due to some internal fault. if you're plugging it in, i'm going to guess you can hold it in your hand. does it get hot? if it's the culprit and is dissipating enough power to dim the lights, well wow... time for a new radio or at least see if an older or different one does it too.

there's a reason for 2ga wiring, deep-cycle batteries, and high-output alternators.

The lights are dome light themselves are good. I tested them straight off the battery and they are plenty bright.

I have the radio totally disconnected as well as the combination meter, that's the only time the lights come on but they are very dim. As soon as I connect the radio or the blue connector on the back of the dash they shut off completely.

I will try pulling other fuses to see if that changes anything but I'm convinced it has something to do with the combination meter. I filled up my gas tank yesterday, went to reset my trip odometer and it was at like 35 miles. Reset it anyway and drove home (5miles). Started it up to head to work this morning and it had reset itself. Every time I turn the truck off and it sits the odometer resets itself.

SO would I be correct in thinking the dash itself is the problem?

Do you have the dome circuit wiring for your 99? If so can you post a copy of it so I can review it?


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I believe this is the correct one, I found it on another thread about the dome light in a 99.

Attached Images

106 Interior Light.pdf (58.0 KB, 76 views)

if the trip odo resets, that's sounding like a battery disconnect, which is really nonstandard unless one does this manually (e.g., removes the connector for one's safety or for testing). what you've just related seems to masquerade as a battery problem, but based on your earlier post, your battery maintains at 12.6v. i start to wonder if you might have a relay that's going bad or may not be fully seated. outright failure is fairly rare for relays, but not impossible or unheard-of. would you check to make sure they're seated? also a random question: do you know if the vehicle was ever flooded and took on water and/or mud way high in the engine room? any high-water line in the fusebox? far-fetched, but worth asking given that you've got other rando electrical issues.

did you check the current draw with everything off (no radio, no fan, engine off, no lights, no add-ons like a scangauge, and so on -- just nothing, as if you planned to leave it for a month)? there would be a small draw from the clock, but not much else. if you're getting more than a few dozen milliamps, you've definitely got a phantom load to fix, and though that may not be the root of the issue regarding your dome light, it's in league with these issues.

my $0.02: i don't think the dash (i'm gathering here, "dash" means the combo meter) is the problem. i could be off, of course, if for instance there's some unexpectedly janky wiring back there which /cough/ i would know nothing about, looking at my own vehicles /cough/ but... i would want to see what's going on with some of the big hitters like the radio. is it using the stock connector, or is it hardwired like i had to do with mine? do you have any indicator lights that simply don't light?

does your combo meter get warm or hot? whatever's causing a huge current draw (if that turns out to be what this is), would need to be dissipating a lot of heat, and would nearly but not totally max out the capacity of the fuse it's on.

another consideration: are the fuses all of the correct rating? so for instance, the dome light fuse should be 15A. that is allowing current sufficient to generate 200W to heat up something. i'm stunned your battery isn't run down after even a few minutes of this.

when issues like this get really deep, it's useful to make a 2D matrix with system components on one axis and tests on the other, and where those meet, record the result.

another edit: do your battery voltage (let's say 12.6v like before) and voltage measured across the terminals of the dome light socket equal each other?

and heck, something more to look into: would you disconnect all of the interior lights (see the diagram for which) *except* for the troublesome dome light, then see if it's still dim? are all the other interior lights dim, too? they all have the same main fuse, so presumably what happens to one, happens to all.

As the 3rd Gen became more modern more and more things that use to he hard wired became distributed modules. You’re instrument cluster is no exception. It’s digital? Yes?

It looks like it is in control of your dome light controls and if your odo is crewing up.......I’d look for a cluster with similar milage and buy it and see how it behaves.

My old 04 Grand Cherokee had modules everywhere. Seats, doors, instrument cluster.....it was there way of saving money on copper wire and having a 2 wire communication bus sending info locally to control things.

In 99 Toyota completely changed their engine and body controls. Your milage may vary....


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can't speak for exactly what's in @906-Runner 's dash but mine is the same year and SR5 spec, and it's not digital. i've had the cluster off too many times to admit to, and it's the old-style boxy thing with spring-load twist lights and exposed traces all around the board, and three molexes to connect the silly thing to their extra-short cables.

The combination meter is the instrument cluster? If your 99 is still analog gauges without digital ODO is it the correct diagram. My 97 drawing shows something else in place of the combo meter.


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thanks for the reminder: on mine the gauges are analog. the odo is digital.

I actually did try plugging in another dash from my 2000 parts vehicle, nothing changed. I ordered a volt meter to try testing continuity and power supply stuff to see where my draw is coming from. As far as I know it is not a flood vehicle but then again I don't really know much about its past. I've had it apart a few times and couldn't find any signs of a flood vehicle(sand every, fried electrical stuff, corrosion) but I really don't know where I would be looking specifically. My plan is to just pick away at it a little bit at a time and if I cant fix it I'll just deal with it until graduation next fall and buy something newer.

Got my volt meter tester yesterday and tried it out today. I have continuity everywhere, I tested resistance as well and got around 1 Ohm between all connections except one. I had 12 Ohms between my dash and my radio; I’m guessing it must be pinched or something, but still barely connected? Any ideas how I could figure out what it is?

tl;dr: measure current in addition to resistance, to see if something is sucking power.

long version:
in addition to ohm readings, switch it over to amps and see what you get using the same technique and connections. ohms will tell you for instance that some device has internal resistance, and it's not out of the question that 12Ω simply is the sum total of your speakers. amperage though should help to determine if something is power-greedy when it shouldn't be. i wonder if there's something goofy with the stereo, such as it has a built-in sub that is always on and simply doesn't make any sound unless it gets signal. in my '95 pickup, i learned the hard way that the rear (jumpseat) speakers are active, and they will run down a battery if not specifically switched off. i had hooked a new stereo to *unswitched* +12v and had a separate manual switch for it. i came back the next day and -click- no power. after i recovered from the doomed feeling, i realized the error of my ways, and now in that vehicle i have two switches -- one for stereo on/off, and another for active rear speakers on/off. this came about because the stereo did not automatically turn off the rears when it was powered down. weird.