Low/High beam inop

[Twan]

Hello all, trying to figure out an issue with the '00 SR5 I picked up the other day. I drove it for the first time after dark last night and noticed the headlights were very dim. Did some poking around and it appears the headlight switch on the stalk doesn't do/change anything as far as the headlights are concerned. All the other lights turn on and off like normal. It appears that the DRLs function normally, but that was the only light I was getting out of them. The high beams come on when the stalk is pulled back, but do not come on when the stalk is pushed forward.

What I've done so far:
Checked all fuses, all are fine.
Checked the relays. Both click when the stalk is pulled back, nothing when pushed forward.
Checked the bulbs themselves. Both filaments are fine, lows are lit with the DRLs and highs come on when the stalk is pulled.
Unplugged the DRL module next to the battery. DRLs were off, no low beams when switched on, high beams work when stalk is pulled.

I'm not sure what to check next, or not sure what could be a common failure since this is my first Toyota. I haven't been able to find any threads that address this problem, as all the similar issues seem to be burned out bulbs. Any suggestions?

 

[TheDurk]

You said you checked ALL the fuses. Did you check the 7.5 Amp DRL fuse? As I read the schematic, if that is blown, you will be stuck in DRL mode. Check fuses with a meter, test light, or put in a KNOWN good one. Don't waste our time telling me you LOOKED at it. Otherwise:

I'd guess the stalk is not telling the system you want headlights. Bad stalks are quite common at this age on our trucks. To confirm this, trace the circuit described in the first sentence in Paragraph 2 at the end of the link below. Start at DRL relay #4, and verify it is working when stalk is switched to HEAD. (I bet it isn't.) Stay with stalk at HEAD. So, either you don't have 12V+ at Terminal 4 (I bet you do if that fuse I mentioned above is OK) or you don't have ground at Terminal 3(I bet you don't), or the relay is bad(also possible). If no ground at T3, it's either the stalk or the DRL diode #1 is open, or a connection/wire in that path. Trace it back.

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/ewdtmc2/ewdtmpdf/ewdsourc/2002/024runne/systemci/020hldrl.pdf

 

[Twan]

Multimeter confirmed continuity/voltage at that fuse. I'm unfamiliar with where the DRL relay #4 is.

 

[Twan]

Before I called it a night on it, I also noticed the fog lights don't work either. I wonder if that also points to the combination switch.

 

[the great him]

replace the DRL fuse with a NEW fuse to check for sure. if you still have nothing, you have a bad switch or stalk, and will need a new headlight switch.

 

[TheDurk]

Multimeter confirmed continuity/voltage at that fuse. I'm unfamiliar with where the DRL relay #4 is.

Look at page 30 on the attached. It's listed as D9 behind the dash close to the passenger door. The diode #1 I referred to is D12, up higher and a little more toward the center.

But my money's on the stalk. If you ground the green wire at Terminal 8 on the stalk (with the switch at HEAD) and the headlights work, you will know that it's the stalk's fault. That will save you digging into the dash.

http://tacoma.site40.net/4Runner_96-02_Repair&Wiring/techinfo.toyota.com/ileaf/ewdtmc2/ewdtmpdf/ewdsourc/2002/024runne/electric/parts.pdf

 

[Twan]

Thanks for the info guys. I'll take another look tomorrow, try your suggestions, and hopefully that'll be the end of it.

 

[Twan]

Grounded the wire at terminal 8, high beams came on. Looks like I'll be ordering a new stalk. Thanks again for the help.

 

[Twan]

So, it's just my luck that I get the new switch and it's not the problem. Still no low beams and only flash option for highs. Looks like I'll be digging under the dash.

 

[Twan]

This is getting frustrating. No power or ground at DRL relay 4, can't get to the diode currently since it appears to be buried up high under the dash. What's confusing me right now is if I pull the DRL fuse, they stay on still. I guess I'll keep at it and see if I can get to that diode to check for continuity.

 

[TheDurk]

This is getting frustrating. No power or ground at DRL relay 4, can't get to the diode currently since it appears to be buried up high under the dash. What's confusing me right now is if I pull the DRL fuse, they stay on still. I guess I'll keep at it and see if I can get to that diode to check for continuity.

If you don't have power at DRL Relay #4 on Pin 3, you need to swap that DRL fuse. It's a straight shot and the diode has nothing to do with it. But it doesn't make sense. If the heads worked when you grounded the wire at T8, then you HAD TO HAVE HAD both ground and 12V+ at DRL relay #4 and there had to be continuity at that diode. Thus the fault was in the stalk. I'm sure of this. Are you checking with the switch set to HEAD? If not, SOMETHING changed since you did that test or the new switch is not connected correctly. What happens when you ground that green wire at T8 now with switch at HEAD?

 

[Twan]

When I grounded the harness at wire 8, high beams clicked on as long as I kept it grounded. I swapped the fuse out with the starter fuse and nothing changed. The new switch didn't appear to change anything. Lights were switched to on while I was testing everything.

As far as checking what happens when the harness is grounded now, I'll have to check later once I'm home. Worst case scenario, I'm just going to let my friend take it down to his shop next week and have his employee that's good with electronics have a go at it.

 

[TheDurk]

When I grounded the harness at wire 8, high beams clicked on as long as I kept it grounded. I swapped the fuse out with the starter fuse and nothing changed. The new switch didn't appear to change anything. Lights were switched to on while I was testing everything.

As far as checking what happens when the harness is grounded now, I'll have to check later once I'm home. Worst case scenario, I'm just going to let my friend take it down to his shop next week and have his employee that's good with electronics have a go at it.

And the other question is whether there is ground on the stalk at T8. It seemed that that is all you were missing. I assumed the old stalk was receiving ground but not passing it because otherwise nothing would work.

 

[Twan]

Time to revive an old thread. I mostly forgot about this since I don't really drive the truck much and never really drove it at night. I took it to a Toyota specialist for a little bit of worked and asked him if he could track down the issue. What he found was that the issue lies in the gauge cluster. The entire headlight circuit has continuity except where it goes into the cluster. Now I'm wondering if this is something that can be repaired easily, if I can scavenge some parts off a salvage cluster, send it somewhere for repair, or if I should just replace it and have the mileage programmed by a repair shop? Input?

 

[Twan]

Local search has been fruitless for someone that will reprogram a new(to me) cluster. Speedo shops around here won't mess with digital odometers. I'm not against shipping. Anyone?

 

[TheDurk]

Time to revive an old thread. I mostly forgot about this since I don't really drive the truck much and never really drove it at night. I took it to a Toyota specialist for a little bit of worked and asked him if he could track down the issue. What he found was that the issue lies in the gauge cluster. The entire headlight circuit has continuity except where it goes into the cluster. Now I'm wondering if this is something that can be repaired easily, if I can scavenge some parts off a salvage cluster, send it somewhere for repair, or if I should just replace it and have the mileage programmed by a repair shop? Input?

The only thing I can tell you is the issue then is with the auto-off feature. If that is not important to you, you could just bypass it. Fixing it will mean some delicate on-PCB microsurgery, I would think, and that may or may not be doable. Probably not. I have no idea on the odometer.

If you want to bypass the auto-off, post back and I'll figure it out.

 

[Twan]

The only thing I can tell you is the issue then is with the auto-off feature. If that is not important to you, you could just bypass it. Fixing it will mean some delicate on-PCB microsurgery, I would think, and that may or may not be doable. Probably not. I have no idea on the odometer.

If you want to bypass the auto-off, post back and I'll figure it out.

I appreciate the help, and if anything I could bypass it as a fallback. I might need to anyway since the reason I decided to get it fixed was so I could have a fresh starting point for the projector retrofit I plan on doing here soon. I also have someone local looking into a new(used) cluster for me and found a local place that supposedly does odometer programming but is out of office for another two weeks. If anything, I'll just swap the clusters to confirm the fault.

 

[TheDurk]

I appreciate the help, and if anything I could bypass it as a fallback. I might need to anyway since the reason I decided to get it fixed was so I could have a fresh starting point for the projector retrofit I plan on doing here soon. I also have someone local looking into a new(used) cluster for me and found a local place that supposedly does odometer programming but is out of office for another two weeks. If anything, I'll just swap the clusters to confirm the fault.

OK, First, you will need a new wire diagram, as that link died with the the Tacoma on-line manual that was so great while it lasted. Also the connector pin-out list.

 

[TheDurk]

To restore normal headlights, just bridge the Green wire on Pin 5 to the Red/Yellow wire on Pin 1 of Plug C27 on the dash cluster. The pin-out of C27 is shown on page 262 of the second attachment.

 

[Twan]

To restore normal headlights, just bridge the Green wire on Pin 5 to the Red/Yellow wire on Pin 1 of Plug C27 on the dash cluster. The pin-out of C27 is shown on page 262 of the second attachment.

Sweet, I may just de-pin those two wires from the plug and jump them that way.