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I have a 2007 Toyota Highlander Hybrid. The right turn signal is working only occasionally.  Left has no problems. When the right is engaged, it will flash 1-5 times, then quit. Next time it is engaged it will only flash once then quit. When I say quit, that means the signal arm/switch is still up/engaged, but the relay stops clicking and bulbs stop flashing. I have replaced both right signal bulbs, replaced the relay and replaced the turn signal arm/switch. Still the exact same problem. I now know for sure it is not the switch as it does the same thing when the flasher is engaged - flashes a few times then the flasher quits (both sides in this case). I'm at a loss and would greatly appreciate any ideas.  Thanks in advance. Michael  

hmm... strange.. this is a 2006 diagram .. so there is a chance its different..  

the turn signal switch contacts seem to make and break connection to ground.. this sends ground signal to one or the other wire into what they call the turn signal flasher..  more to come on that... here is the turn signal diagram for the 2006 version.. still looking for the 07 version..



i have a question.. are the turn signal lights on a separate bulb on these models..  an orange or amber lens..  that they don't share the bulb with the brake lights..

this second diagram seems to be slightly different

 

Strange one indeed.  You are correct on the separate bulbs, both front and back. I believe 07 was the last year of that model so 06 is likely the same or darn close. As an aside, my 18 yr old son plowed into the back of someone in this vehicle about 6 months ago. All worked fine until about a month ago when this started. But the light assembly, etc are all new because there was an "event" where things needed to be rewired, etc. Thought that might be worth mentioning.  Thanks again for the thoughts/schematics.  

there seem to be turn signal switches available already in the aftermarket...  all three under 150 bucks..

you should be able to .. With care... get the turn signal switch off.. and OHM the circuits... there are probably 17 or 18 individual connector pins on this switch.. and it could be three of them..   i prefer to verify the switch is bad before changing it.. but at shop rates.. and since i have it torn down.. its usually cheeper to just change it first..


warning... PLEASE.. if you are going to do this your self.. please invest in a factory service manual in print.. or a digital copy..
read the actual info before doing the work... you have VERY expensive air bags to contend with...  and HIGH VOLTAGES between the battery pack and the engine/controller.. so you probably won't encounter them inside the dashboard.. but you have to read the factory manual info before doing this..




Turn Signal Switch
Part Number: SW3539
Notes: With fog lamps and automatic headlights


Turn Signal Switch
Part Number: SW2813
Notes: Without automatic headlights and without fog lamps


Turn Signal Switch
Part Number: SW2814
Notes: With fog lamps, without automatic headlights  

with the ignition key turned OFF...

sit there and work the turn signal switch a BUNCH of times...

this will hammer the contacts hopefully without any load going through..    perhaps that will beat the dirt on the contacts away.. making it work again..

this has worked.. on GM ignition switches.. to restore them slightly enough to eliminate some of the problems..

doing it with the power on.. adds electron flow to the issue and continues the arcing that goes on...

its a cheep fix...

could also be what they call the turn signal flasher.. i looked at my toyota parts supply online.. i could NOT find any thing called that.. but i only took a 10 minute search through the many many pages...  

That was my third step. Bulbs, then relay, then the switch you show. Did not change the behavior so it's not the switch. Also, since it does it when I push the flashers button (which I believe does not go through the signal switch) I think that points to not being the switch?  

when it goes into failure mode..

does it work only on ONE side????

that would tend to indicate the flasher unit may be bad..

or have cold solder joints inside..  

i have not worked on these.. so i Understand how most systems work..  and the wiring diagrams help a lot.. i just don't know what the turn signal flasher looks like on this model...

if it only works on one side with the flasher..  look for the grounds for the bulb sockets where they attach to the rear body..

let me look around..  

item 81980...  but it should have 8 wires on it...  

When I engage the flasher, both bulbs flash a few times, then both stop working (relay stops clicking).  

8198053020

Alternate Stock Code 819800E010; 8198050020

airtex/wells   1R2229


you could still have a bad ground to pin 7 of the relay.. that goes away under load.. but that would not explain one side working and not the other...  pin 7 is grounded to the left cowl side panel under the dash..

when the side that works is working.. is it as bright as the other...    can you check all 4 bulbs.. and any side bulbs .. to verify brightness is constant between the bulbs.. not dimmer on the side with the problem ..  

well you said at first. that you replaced the relay already..

let me think about this for a few more minutes..

i am taking that it was a NEW flasher...do you have the old one still..   can you pry it from the shell and examine it for cold solder joints on the circuit board where the wires poke through and are soldered .. circular cracks /rings in the solder puddle about half way up the puddle shows that has failed..

i have GOTTEN used parts that looked new in boxes before..  parts swappers..


log in.. check messages to the left of where you log out at..  

power to the turn signal flasher comes in on pins 1 and 4..

pin 1 gets power from the 7.5 amp ign 1 fuse..

pin 4 gets power from the 15 amp HAZ fuse and that is probably under the hood..    

with a circuit tester.. (test light..) check these fuses for power on both sides .. while the failure is happening..  and if you have a proper shaped probe.. you might also be able to gently probe the grip terminals that hold the fuse also..     working the fuses in and out a few times cannot do so bad.. you can also feel if the terminals that hold the fuses have lost their grip .. causing intermittents..

can you see if the horn blows when the hazards fail????  its supplied on a different fuse but from the same fusible link...  follow wiring diagrams . you will see what i mean..  and i don't expect you to or anybody to  be able to read them.. i just do this a lot..


can you reach the relay with it plugged in..    do you have a bulb type test light..   can you identify which are the wires  by number..  

pin 1 is power into the flasher ..  constant power

pin 2  feeds the right bulbs with flashing power..

pin 3 feeds the left bulbs with flashing power..

pin 4 is power from the ign 1 fuse and is switched  on with the key.. and off with the key..


pins 5 and 6 come from the turn signal switch contacts and are grounded to cause the flasher to operate in one direction or the other..

pin 7 is ground for the flasher electronics..

pin 8  is from the flasher switch and the various controls .. please be careful to NOT probe this wire..   if you put too much load on it..   you stand a chance of damaging the electronics in the computer or display ...

do you have a some kind of digital volt meter???

and a circuit tester ...  

so you could probe the wires into the relay.. while its working and when it fails. ????  

I will get on this as best I can tomorrow (between bowl games ). I think I can test most of what you have suggested. The one answer I can give you is all lights/bulbs are showing the same brightness - no dimming. I'll let you know if I have question. This is a big help.

And yes I do have the old relay.  

another thing...

you should be able to OHM or use the continuity beeper setting on your meter between Ground and the 5 and then the 6 wire..  when you work the turn signal.. you should get a nice clean beep from  the meter when you work the turn signal switch......

this will prove the turn signal switch contacts are good...

you will want to set the digital volt meter to 2 volt DC scale and probe pin 7 ... and the other on ground.. while you operate the switch.. until the lights fail..   if you have a bad ground connection..  you will find more than 0.02 volts..  if the ground is bad... you will get higher than 0.02..