hey guys im pretty sure the sidemarkers are not supposed to blink with the blinkers/hazards on correct?

second question. my right turn signal arrow in the cluster lights up and stays lit when i pull the switch for running lights/headlights, turning lights off makes the arrow go off too.

what the heck can cause that. also i do have both flashers unplugged kinda to see if it would go away and still lights up. the blinkers worked for two months last summer but otherwise have never worked. anybody know where i should start looking. the cluster/circuit board seems to be fine.

 

I had the exact same issue, though mine was intermittent, it came and went, i didn't do much to diagnose it other than replace bulb/clean the socket, problem went away for a long time then just recently started acting up again, i'm thinking maybe a bad/broken ground wire...maybe fmc400 will give us some sage advice.

 

The side markers should never blink under any condition. They are purely isolated to the running-light circuit and do not run through the turn signal switch in any way. The only way this can happen is if a previous owner has modified the wiring.

This is a highly common problem and is called "ground shift." Circuits that use 1157-style bulbs are susceptible to this because both filaments (running light and turn signal light) share the same ground in the bulbs up front.

The reason you see your indicator light come on is because one or both of the turn signal sockets up front is losing ground internally. When you turn the headlights on, current is supposed to flow through the running light filament and back to ground through the socket terminal and then the radiator support. Because that connection is gone, the current returns to ground back through the turn signal filament, through the indicator lamp (since they're on the same circuit) and back to ground through the instrument panel. Current through the filament is what causes it to light up.

I bet you will find that your turn signals do not work properly either, for example, your turn signals probably won't work with the headlights on. If they do, they won't eventually. You will need to replace both front turn signal sockets (even if the problem is only one, you want to replace both as a pair). Sometimes the problem is actually caused by the rear sockets, but it is less common. You can replace all four for good measure.

 

I'm one of the guys who wires his side marker lights to flash. I do it because theres a lot of people who have tunnel vision and don't notice me on the road beside them. My itty bitty 24 foot long F350 dump truck is really hard to see sometimes. That flasher has saved me a lot of stress and prevented a few accidents, which is probably why it's illegal in some provinces, but hardly ever enforced.

 

okay, i think i would like to mod my sidemarkers so theyll blink too like privater eh says. i bet i could add another seperate bulb in the lights or go full LED.

my next project is to make 100% new wire harness sections for the front lights, i may as well try to plan out to use two or more bulbs(front parklights) there as well with seperate grounds. i never thought that the 1157's would backfeed like that. a guy could add some diodes to prevent that too.

im also going to keep expanding my ground "harness" and try to strap each body piece to frame.

 

It is very simple to do. the side markers are a one filament bulb (#194) with two contacts. one hot and one ground. you will need to isolate the ground wire in the harness near the socket, this can be done with a test light with the running lights on and the bulb removed . in an effort to simplify the technique, you remove the ground path from the socket and wire it (the wire from the socket) in conjunction with the respective hot turn signal circuit... with this completed, with the running lights on, the bulb will find its ground through the rest of the turn signal hot side. And with running lights off, the turn signal current will flow in reverse and find a path through the running light circuit... With your lights off, it will flash turn simultaneously. With running lights on, it will burn as a marker, then alternate, with the normal turn signal. GM used to use this in the seventies, and I used it for big rig "rookie bars" and of course my Fords . just remember to do a professional job, and protect your splices from moisture. Scotch Loks are the devil

 

That's how it played out in my case, but it was only the turn signal in question that was affected, the other three continued to work just fine.