Not used to these newer computer run trucks, but I'm trying to find the relay or 12v source that activates my hazards so i can tap into it to run an additional relay for a set of rooftop hazards. Anybody point me in the right direction?

 

If anybody has a diagram for the TIPM that would help.

 

Look up a member on here, Weedaho. You can download the service manual for your truck from his signature Schematics in there.

 

I wouldn't tap into that circuit, the TIPM is very sensitive and will shut down the entire circuit if it sees too much draw on it...

But considering is it the hazard lights it might not be tapped into the TIPM... it might be independently wired, one way to find out is to leave them on along with one of the map lights turn the truck off and wait 5-10 minutes until the TIPM turns everything off, if the Hazards stay on it might be safe to believe that they aren't hooked up to the TIPM.

If that's not the case then You're better off adding a relay, switch w/ a blinker relay hooked up to the circuit...

Personally I'm terrified of tapping into the TIPM for anything, especially when I read the horror stories of it locking down and requiring a dealer reset or a complete replacement.

I looked at some wiring diagrams and I haven't found the circuit just yet.

Definitely post up what you find, as I'd like to know too.

 

In later models everything goes through the TIPM including the hazard switch. A relay barely has any draw on it whatsoever so im not worried about that. I just need to trace the actual wire that runs into the dash's hazard button, it would help if my HAYNES manual included diagrams for post 05 trucks, but it doesn't. Looks like my only solution will be to pull my column apart and find the color of the wire running to the switch then match that up behind the TIPM.

 

Yes I know, but there are some DOT regulations that prevent shut-off (via electronic/digital control) so it might be directly wired to a relay of some sort, or it might just be on the Battery Powered Side of the TIPM... I'm not 100% sure what the case there is.

You've peaked my curiosity.

 

Correct, Hazards ARE an independent circuit to keep them from being affected by other catastrophic failures, but I still believe it sensible to assume that whatever circuitry controls them is still located in the PDC/TIPM, as far as a relay goes I'd love if it were as easy as being an independent relay like older trucks, thats a easy tap, but I think everything in these newer ones are solid state and have no flasher/relay units at all.

 

Ok so I decided to take apart my steering column clam to actually see if I can determine the color code of the wire coming out of my hazard switch. Turns out the entire multi function switch and hazard switch are one assembly with 3x 4 wire plugs connecting it to vehicles harness. Im assuming the wire Im looking for is one of the ones were the plug is closest to the actual switch, but in the spirit of Murphy's law my multi-readers probe broke lol. All well, ive been looking for a good reason to get a decent power probe, maybe this is it.

 

The more I dig the more I think this is a completely digital switch... Unless I use a high end programmable relay I think i'm boned here. It looks like the trigger for the hazards are if pins 2 & 3 of the connector pictured have a resistance of 115-128 ohms... so if anybody knows of a compact programmable relay that can be triggered when a load is between x and x let me know lol.

 

You'll need a PLC to trigger that... but what is the current running though it? I'm betting it's under/around 10mA, which won't trigger a standard relay....

I say you're better off using a standard relay, switch, and a blinker relay run off the battery.... Otherwise we can seriously over complicate this with a PLC and some fancy wiring.... lol

Sure it would be a little more work, but it will be reliable and you won't risk really screwing that TIPM up if something goes wrong.