I'm having issues with my flashers/turn signals. When I use my hazards or turn signals the dash blinks once with the corresponding light(s) and the outside lights don't turn on at all. however the lights DO turn on with my parking/headlights on. I checked the fuse under the hood and swapped it in both cases no change. Is it possible that both my flasher relays died at the same time?

 

Fuse 14 under hood? IDM module (back of fuse box under dash? Time for the RAVE, a meter, and circuit diagram details. Electrical diagrams presented in original Klingon.

 

I KNEW I should have watched more TV...

 

Check out the schematics on older trucks, you'll be a believer...

 

Ok I'm bumping this since I still cant seem to track down the problem. I'm hoping someone else ran into this and has tried something I haven't yet.

All fuses are good and tested. As stated when I use a signal OR turn on the hazards the corresponding dash lights blink only once. The lights on the outside of the truck do not blink. The little peanut lights in the front amber lights turn on when the headlights are on but the large bulbs do not. I checked the passenger bulb and there is a short across the socket. I'm exactly sure how the flasher relays work and if that should be the case or not. ANY help would be amazing as this problem has gone on long enough and is driving me more crazy than when my front cover was leaking!

 

Consider the attached drawing from the RAVE. The turn signal commands the BCU to do something. The BCU does this by commanding the IDM module on back of the fuse panel to operate those relays. The IDM also has a role in other circuits.

There is no "flasher" thermal timed relay. The BCU and the IDM handle that timing electronically. The BCU sends digital commands to the IDM. So while you can measure the input to the BCU from the turn signal switch, seeing the command to the IDM would be beyond a voltmeter. An IDM is "synced" to a BCU by leaving the key on for 5 - 10 minutes. If replacing the BCU you'll need a shop level computer, a basic code scanner is not enough.

Pix of back of fuse panel, boneyard near you?

 

So to resync I need to put the key in, in the "on" position but NOT started or does a 10 minute drive around town count to resync?

 

key on, no start

If swapping fuse panel, please disconnect battery first. That IDM module also controls door locks, etc.

 

Ok let it sit in pos 2 for like 20 mins and no turn signals or hazards still. Same deal..single dash flash and nada.

What am I in for to get a new IDM? An entire new fuse panel from any model year then repeat the 10 minute thing or do I have to do some other crazy stuff first?

 

Yep, whole fuse panel. And then the 10 minute key on to sync with BCU. The LKQ u-pull-da-partz boneyard near me charges $15 for a fuse panel. Fall weather makes it more comfortable to fly low and fast with the partz vulturez.