Need a mechanic's help with taillight

When my truck was first bagged an shaved up a friend of mine installed diodes for my taillights because they would flash at the same time currently i installed some leds and when i turn on one blinker it flashes solo when i turn on the other side both flash how do i know which one needs a diode and which diode do i need to install so i can have both blinkers working properly.. also currenly my front end is off so i have no marker lights hooked up in the front when i turn the truck on the rear lights automatically come on is this because of no signals in the front??

why did he install diodes? dude sounds to me like you have a ground problem, ditch the diodes and retrace all your factory wiring to you tails and put them back to stock hookup and then wire in you new tails to the factory harness the diodes will cause nothing but problems

eh trust me i have no ground problems the 3rd brake light has been uninstalled without diodes the taillights will freak out it was hooked up with diodes for 2 years now worked fine. I had a bad experience with a transport agency that left my truck open to the elements for a week ripped out my switches and the taillights were damaged .. if i can find out what diode i need i can have my taillights working fine. my buddy who hooked it up is a master tech but thats back in fl an have since lost contact with him.

if it was working good, which i dont understand cause diodes are used in tvs and cellphone and house hold crap. so let me understand he converted from ac to dc current right cause thats what diodes do. if that is the case just replace them all cause there probally is no way with out using a check light to find which one is bad if then

im asking for a mechanics's help cuz i have no clue about this kind of wiring. I do know that diodes cut signals of power from what ive been told. Ive heard a ton of other people with led's that run diode's

Diodes do not convert ac to dc. Im in school to be an electrical engineer.  diodes are used for alot of reasons such as voltage regulators and so on. think of them as sort of a check valve. It all depends on there biasing and there pn junction.  oh and led's are light emiting diodes! I wish I could help with your issue but I wold need all the specs.

the one thats flashing solo is good, the other needs the diode in it, get one thats rated at 12 volts and about .25 amps would be more then enuf, it goes on the ground side of the wiring near the light and the pointed end of it points toward the grounding surface, not toward the light bulb, the reason he installed them is because you are for some reason having a grounding issue could be a ton of things but never the less thats what the problem is. if it were my truck i would find the issue but if you want to use the diodes fine

---------------------------------------------Originally posted by kidbrootalDiodes do not convert ac to dc. Im in school to be an electrical engineer.  diodes are used for alot of reasons such as voltage regulators and so on. think of them as sort of a check valve. It all depends on there biasing and there pn junction.  oh and led's are light emiting diodes! I wish I could help with your issue but I wold need all the specs. ---------------------------------------------then you need to stay in school, cause the meaning is and i quote: the diode is considered a check valve for electric current, This unidirectional behavior is called rectification, and is used to convert alternating current to direct current, and extract modulation from radio signals in radio receivers. any more questions i know what im talking about if you dont believe me here you can go here and check your self,                                                                                                http://en.wikipedia.org/wiki/Diode this way you can see im telling the truth

ill tell you an easy way to tell i used this trick when i installed car stereos, if you can see the diodes shine a light on them to see them good and see if there is a black spot in the middle, this should look like a burnt spot, this will mean it is bad, i used this trick alot when i worked on amps and tvs

Your right dropped civic thats my bad.  I do agree that it seems like a grounding issue. I would trace it back and fix the problem at its source if i were you. But to each his own. good luck with the fix.