Hey all, I just installed sr5 map lights on my non sr5 4runner. I have wired them up similarly to how it is wires from the factory. I checked the map lights with a meter and there is 12v going to them but the lights just won't turn on. So I replaced the bulbs and still nothing. Here's what I did. Maybe someone can tell me if I wired them wrong.

1. I disconnected the dome light connector. I removed both blk/wht wires from both ends because I don't like hacking into any harnesses. And I could easily revert to stock if I wanted down the road.



Index finger is pointing to wire I added between blk/wht wire from harness to dome light wire.

Middle finger is pointing to wire going to map light.

This would be similar to how it would be wired from the factory, no???

The wire gets 12v and the map light gets 12v but the lights just don't turn on. Help please! This has been bugging me for the past couple of days. TIA!!!

 

Not exactly understanding your setup, but it sounds like you need at least one ground. If so, use a mounting screw if it contacts metal and pigtail to that, solder to lamp socket if needed. Dome light still works it sounds like?

 

Stock wiring for the stock map light is like this. (I know first hand because I was at the pick n pull a couple days ago.) There are 2 wires from dome light (blk and blk/wht) that runs along top of drivers door, down the A pillar and connects to the harness where the kick panel is. And connected to the male end of the connector which also has 2 wires blk and blk/wht. The map light wire (blk/wht) runs behind the visor and is spliced into the dome light wire (blk/wht) at the top of the A pillar. There's only one wire for the map light. I believe it is grounded when the 2 mounting screws in the map light are screwed in. See pic below.




What I did is run a wire between to 2 blk/wht wires about 6" and had another wire spliced in the middle of this that runs to my dome light. Like how it would be stock. But instead if splicing at the top of the A pillar I spliced where the kick panel is. Hope this makes sense.

 

i fixed the code on your pic so that the img would show up.

also you are going to want to insulate the spade connectors you used in your pic. You are just asking for a short with the exposed connections.

 

Gotcha. Yes, that light appears to ground through the mount screw. If you have 12v at the light either the feed line is contacting the ground before it runs through the light filament, or the ground is bad. Bulb is good, I assume.

If you touch a voltmeter to the bare feed wire and the other probe to the screw you should have 12v, then your ground is good. Can't see from the angle, but your feed line should run straight to the bulb, through the filament, and then to ground. If anything there is bent and it touches ground before the bulb or there is a break in the circuit you won't have light.

 

Yes I was planning on doing that once I got the lamps to work. It was kind of a mock setup to see if things worked out. I plan to use shorter wires to keep things cleaner under there.

 

"Bare feed wire?" You mean the exposed part of the grey wire in the pic? Or the exposed part of the white wire? The part where it's soldered?

I will try when I get back home. Had to leave for a bit...posting from my phone...

 

Is this how you meant? If it is, there is no 12v. What should I do now?

 

looking at the 88 EWD B/W is the battery voltage .

either a bad ground or the socket is corroded that you can`t see

The way your meter leads are you will never measure any voltage.

it should be between the bottom of the bulb and the side or to a good ground

The bottom of the bulb is one point and the sides of the bulb are always the ground.

just what year??

 

Is the tab coming off the screw connected to feed side then? I think I missed that white wire blending in back there last night, so assumed the screw was ground side.

Basically, you need to have a complete path for the electricity to travel from one terminal of your battery, through the switch, through the light, and back to the other terminal. The switch breaks and reconnects that circuit. There could be a flaw or corrosion in there, but less likely than other scenarios, IMO. You could rule this out though by putting one probe on the bare wire before the switch and the other probe in the light on the circuit's other side, the wire NOT connected to the switch, and should see 12v.

Like Wyoming said, if the switch is on you should also see 12v between the side and bottom terminals of the light socket.

And again, if any of the metal in your light is bent and touching where it shouldn't be (tab at lamp base touching socket at lamp sides, etc) the electricity will choose the path of least resistance and not flow through the light, so check that.

When you said before that the map light gets 12v between which wires were you measuring this?

 

I ran into that one time. I swapped the leads at the light connector on the maplight and that fixed mine. I dont fully understand it, but talking to another member is somehow the electric trys to run the wrong way thru the ground?? or somthing like that. Like I said I dont understand electric but it might be enough for an electrician to explain it better. Might try reversing the polarity at the connector on the light.

If I recall right, one of the mounting screws on the passenger side is also a ground to the roof of the truck. In the picture above, I think I see the ground eyelet that is to help act as a ground.

 

It's an 88

I will test again when I get home later today

 

a little physics lesson.

Electricity is the flow of electrons through a conductor.

Electrons are a negatively charged particle which means in DC circuits they always Flow negative to Positive.

This is why all the service manuals say to remove the negative battery cable before doing anything.

Now for some reason some person with no real world job thought in teaching electrical theory we should just think the DC current flows positive to negative .

In High School I had both the physics and electrical teachers about to have a gun fight several times.

So in Physics class current flowed one way and in electrical the other talk about confusing .

I am sure if I look I can find a Text book stating this.

 

 

Cute!!

 

I'm still at work and haven't tested again but the headliner is between the white plastic and the metal bracket where the ground screws screw in. Could this be preventing a good ground?? Just think out loud... If it is, I could cut off that piece of the headliner so the white plastic of the map light housing is directly touching the metal bracket. I will try all suggestions posted here when I get a chance...

 

No change? You're in luck, my '88 is an SR5. I popped the light out to see what's going on.




In the first pic you see the screw hole and main feed wire, the screws are what the light grounds through. I assume that even the non-SR5s had metal mount holes there as pictured, if so and you are screwed into at least one, you have ground. The wire you had the probe on was a redundant ground, connecting the two screws, you will not get voltage from that, you are measuring ground to ground. If you push the switch so the light is on and hold one probe on a screw and one probe on the OTHER wire you should have 12v.

If not, keep a probe on the screw and move the other to one of the wires under the switches - on the near side shown the second pic, toward the switches/vehicle rear, or to the small tab underneath the switches connecting to the main feed wire. These are always hot, the other two coming off the front of the switches are switched hot. If you have 12v here your switches are bad (unlikely). If you still have no power then you're tapped into the wrong wire.

 

Sorry, I haven't had a chance to try again as yesterday was my middle son's bday.

I will probably try again tonight or sometime this weekend and I will let you know what I come up with!

FYI non-SR5's do not have that metal bracket. The maplight is actually a 3 piece part. A "house" shaped flat metal bracket that the rearview screws into which actually holds it in place. The white plastic map light housing also screws onto this bracket, then the cover (which snaps on). You will not be able to add these map lights to a non-sr5 without this bracket. Just FYI for anyone trying to do the same! =)

 

I peeled the headliner back a little and slid it in. Then put the trimming back in to hold the liner back in place.

 

Well get the bracket bound to be some floating around