my 2008 prius has a constant issue where it will burn out the tail running lights. I finally replaced the lights with LEDs. This made this issue go away for longer periods of time but still in the end comes back. I still have a problem of getting pulled over for the lights going out. When I get pulled over I will take the officer to the back and wiggle the lights which will make them come back on. It seems like a wiring issue but today it threw me for a loop. when i was wiggling the left side (always the left side) the right side also went out but would some times flicker after messing with it. Im wondering if this could be a relay and if it is where is that located? This has been an ongoing issue for a couple years now. I usually wont know its happening until im pulled over. this is a danger so i want to finally get it fixed.
First thing I would do is check the chassis (ground) connection for the lights, which is under the latch for the rear hatch. Make sure the bolt is tight and not corroded. You have to take all the stuff out of the rear to get to it. Visually inspect all the wires while you are there.
I will look for it but do you have a schematic or any other info that can help me out like what i need to remove to get to this?
So after checking every fuse and messing around with the wiring i have come to the conclusion it must be a relay or switch of some sort. After messing around on my car for a few hours trying to fix this issue i start the prius and the left tail light is on but the right is off. then about 5 seconds later the light goes out without me touching anything and wont come on. any thoughts?
Here is the schematic for the lights. Very simple. I don't think it is a relay. Somewhere there is corrosion that is causing intermittancy, or else there is abrasion that is causing the wires to ground. The ground labeled BN is what I think is the possible spot. Take all the stuff out of the back and check around under the hatchback sill and latch area. Tighten and clean any chassis ground connections.
Take out the connector and look at it in the light with a magnifying glass. Sounds like the connector itself is corroded. This could be caused by a water leak in the trunk which we have heard many reports of. Do as Nh70 says take everything out of the trunk especially the spare tire and look for corrosion around bolt heads that are attaching wires to the chassis. Lots of them back there. If any bolt heads have corrosion on them remove bolt...sand down the mating area and bolt face and wire lugs.....grease this junction and re-attach. Then apply grease to the bolt head. Make sure the rubber plugs are intact under the spare tire. Nothing should be corroded in the trunk. Should be dry as a bone back there. Also get some spray lubricant or synthetic grease and grease the bulb electrical connectors. I did this to my car 6 years ago and never any issue so far. The connectors may be too corroded to use if so they must be replaced.
I've had several customers with the same issue. Problem was they were getting the wrong lights at one of those auto stores.
Actually, it is a problem of the bulbs and the connectors/wiring/grounds. It takes a lot of patience when trouble shooting 12 volt lighting systems. The Prius is sensitive in this area, but ALL electrical circuits still suffer from the same thing. There are quite a few connectors in the harness. Several posters in the past have had to either replace the connectors within the harness or bypass the connectors altogether with jumper wires to make the lights work. Plus, if you get cheap bulbs they burn out fast. I also agree that the grease helps immensely with the bulbs and sockets. You can find the grease at the parts house. Ask for the grease that goes inside of electrical connections in wiring harnesses. The main thing is to check for continuity which is what NH70 was implying, and Ed also touched on as well as making sure you use GOOD bulbs as OVNI stated. Amazon.com: Permatex 22058 Dielectric Tune-Up Grease, 3 oz. Tube: Automotive Buy Sylvania Long Life Incandescent Mini Bulb 2825 LL at Advance Auto Parts
The bulbs my customers had bought had a grayish tint to the glass. The glass should be completely clear.
That's pretty silly Ovni. The bulb has a number on it. All they had to do was take it to a auto parts store. But I don't doubt it.
A lot of aftermarket bulbs don't have any numbers. Some of my customers have brought in halogen lights in order to replace HID bulbs. That's what the person at the counter told them. I never go by what they say.
