Hi

I have a 1999 4Runner on which the rear passenger turn signal failed on the other day. I assumed a bulb so replaced it (twice), and even tried the functional bulb from the other tail light. Can't get any light. So I pulled out the multimeter and am getting 12 volts to the connector. The tabs inside are not flat as I have read happened. I can't even get a glimmer of light with any manipulation or pressure applied to the bulb in any way. Any thoughts? Seems odd to me.

Thanks

 

you got power... what about ground? hows the bulb socket?

 

Clean the socket with a fitting brush.

does not hurt to also spray with contact cleaner.

The probes from the meter push through the corrosion showing you you have system voltage .

Enough to drive one nuts.

Is there moisture getting in there poor gasket or cracked lens??

 

So I cleaned the connector and still no luck. Everything looks good. One detail I should note is throughout my testing im getting 11 volts not 12. Wouldn't the light still activate even if dim?. I then tested the ground based on this information:


Start at the beginning. Take a voltmeter, on DC and connect the red to the wire going to the bulb and the black to a GOOD ground. If you have voltage, check red to black on the tail light housing. If you have a bad ground the first test should have 12 volts and the second not. If you have power there, try new bulbs. Clean the corrosion from inside of the socket and check the tips in the bottom. If you have no power anywhere, check the fuses, brake switch, etc.

I have 11-12 volts with the red to bulb and black to ground, then negative 11-12 volts with black to power on bulb connector and red to ground. I even tried a new ground wire just incase and still no luck.

No cracks, moisture, or degraded gaskets.

 

are you testing with the bulb in place?

 

No I did the test without the bulb; was that a mistake? I did slip a new ground wire between the connector ground side and bulb connect just to ensure I was getting good ground.

 

For anyone who finds this thread looking for help in the future...

Ended up getting help from a mechanic friend and determined the hot wire was compromised somewhere in the truck so we ran a new one through the interior.

Thanks to those who offered ideas.

 

I am curious just how did you go from having system voltage at the socket to having a bad wire in the harness??

Then not finding the problem but just putting a band aid on.