Independent shop's scanner says "Squib Circuit Short"

[Stranger]

Here's the back story.
I mounted a VIAAIR compressor and 2 gallon tank along with Kleinn Air Horns. I took it to a shop that had done some electrical work previously. I wanted to install a DPDT switch so that in one position when I mash the horn button I would get the sparrow fart horns (city driving). Then when on the freeway pulling my fifth wheel, put the switch in the up position for the air horns.

The shop wired the compressor and limit switch to only run with ignition on, the way I wanted it. They then wired the horns the way I wanted them. Unfortunately, when they first tested everything worked except on a subsequent test apparently the clockspring fried.

I guess Dodge has accessories different than anybody on the planet and run power to the horns and when you mash the horn button it completes the ground circuit, wiring like one would presume back feeds the clockspring and things go haywire.

They installed a second clockspring and wired in a momentary on switch into a different circuit, independent of the clockspring. Everything works except now the airbag light is on. Their scanner says "Squib Circuit Short". Clockspring is correct for the truck, Speed/Audio.

I brought truck home and installed a new correct clockspring myself and have the issue still. Installed with batteries disconnected. My OBD11 scanner shows no codes.

Will a DRB111 scanner clear this? Has anybody had a similar issue? Where could this short be? All fuses are good.

Thanks in advance.

 

[Topzide]

My first question is, "why didn't they wire it with relays to handle the load vs. a switch?". Then, "why didn't they confirm the horn button was a positive feed vs. a ground feed?". Fuses and relays are your best friend when wiring in accessories. I always have a handful of relays on the shelf for that phone call of, " Could you give me a hand wiring in XYZ on my truck?'. I've even have a relay box that has fusing built in for my LED lighting that is on my truck. This allows me to have them flash with both turn signals and with a LED strobe driver. Have a 3 light groupings on the running boards that the middle is on with DRL and flashes brighter with turn signal. The front and rear can flash with strobe driver. All 3 on with running lights. They are a high - low LED. I want to make sure I'm seen!

 

[Ozymandias]

Factory Horn is driven through a relay, why wasn't all that add on stuff not wired right in there.
Sometimes I just don't get it...

 

[Stranger]

Topzide, There is a relay for the compressor. I'm thinking they were looking for an ignition "Hot" wire and tapped the relay into that. I'm thinking it just happened to be the air bag circuit, that's why the airbag light is on.

There is a lead from the right side battery with a fuse that leads to the momentary on switch for the horn solenoid.

I'm going to pull one wire at a time from the new relay and see if the airbag light goes out. If so, then I'll try to find a different ignition hot.

 

[Stranger]

Ozymandias, I originally wanted them to tap into the horn circuit so that when I hit the horn button on the wheel power would either go to the factory horn or to the air horn depending on the position of the DPDT switch. Apparently they first wired it so I would either have factory horn or air and factory at the same time. And they said that's what fried the clockspring initially.

 

[Ozymandias]

They tell you BS - they simply tapped the wrong wire, wired into the signal wire from steering wheel to BCM instead of the power wire from BCM to Horn(s).
And now blame it an the vehicle...
The clock spring can easily switch ten relays at the same time but can't feed a horn no matter how small it is directly.

All you would have needed is a switcher relay 81 & 81A to simply direct the power from the BCM either to the OEM horns or to the ones you added. This is so basic to do. I can reallonly shake my head here about your workshops personal.

Mine are wired the same way, only difference mine are default to OEM so everytime at startup I have to push a button if I want the additional ones - because wouldn't like to have the train horns go off in the middle of the night.

 

[Stranger]

Ozy, what color wire am I looking for, for the electric horn?

 

[Ozymandias]

I'd have to look it up in the FSM - but just the one that goes to your factory Horn from the fuse box.

 

[Stranger]

If you can find one from under the dash, that would be great!
But, wait there's more. Back to my original question, can a scanner clear the "Squib Circuit Short"? Or do I have to get another Clockspring?

 

[Topzide]

@Stranger, Just wanted to make sure there was one. I've seen so many wiring done by others that I'm surprised that the vehicle didn't burn up! I'm planning on a similar install, grabbing the power right at the factory horn and going into a relay. The NC terminal will go right back to factory horn. Then with a micro switch on the dash, I can switch between the 2 different horns as needed. You can put a lot of those micro switches in without needing a lot of real estate! Not sure about clearing the "code", but any good scanner should be able to clear that issue or you'll have to wait for the drive cycle count to clear it. Good luck with repairs.

 

[Stranger]

@Stranger, Just wanted to make sure there was one. I've seen so many wiring done by others that I'm surprised that the vehicle didn't burn up! I'm planning on a similar install, grabbing the power right at the factory horn and going into a relay. The NC terminal will go right back to factory horn. Then with a micro switch on the dash, I can switch between the 2 different horns as needed. You can put a lot of those micro switches in without needing a lot of real estate! Not sure about clearing the "code", but any good scanner should be able to clear that issue or you'll have to wait for the drive cycle count to clear it. Good luck with repairs.

Thanks. I think what I'll do is wire the horns myself the way I want and then wire the compressor the way I want, then deal with the airbag light.

Will the FSM tell me about drive cycle count?

 

[Stranger]

Update. I went to a dismantler and picked up an airbag control module (donor truck was drilled in the driver's side, airbag did not deploy) and an airbag from a different truck.
I installed the donor module in my truck, still get the airbag light. Installed the donor airbag, still get the light.
I disconnected the squib from the airbag to the truck, tested with a VOM and I see a short.
Now, I'm tearing apart the dash, trying to find where the twisted pair runs off to.Going to test the leads that go from the airbag module connector to see if there is a short.
As to the air compressor, I found an open circuit in the fuse box, Fuse 16, has RUN/ACC power on one leg no connector on the other leg. I'm using that for power to the air compressor.
For the horns, I clipped the two power leads going to the stock horns, connected those together and ran them back to the DPDT switch, center connector, then from one lead I ran a wire back to the clipped ends on the horns and connected the wires.
Interesting note, after connecting the electric horns this was, their volume was decreased significantly, sound like a very low volume train horn, lower volume than stock. I'm guessing the added resistance from the new wiring causes this. After I get the airbag figured out, I may run heavier gauge wire for the stock horn circuit. Unless I take the truck and run it off a boat ramp.

 

[bcbender]

For the horns, I clipped the two power leads going to the stock horns

That is where you should install the relay... then use the wires you ran back to the cab to trigger it... that way the original wire length is the same.. use the NC lead to keep the OEM horns on and when the switch is triggered, the NO lead will switch the power to the air horns.

 

[Stranger]

That is where you should install the relay... then use the wires you ran back to the cab to trigger it... that way the original wire length is the same.. use the NC lead to keep the OEM horns on and when the switch is triggered, the NO lead will switch the power to the air horns.

So, I should install a new relay into the leads I clipped from the horn relay and run an output from the new relay to the switch, from another output of the new relay to the stock horns? Should it be a 5 connector switched relay?

Now I'm even more confused. Can you post a drawing so I can visualize it better?

Thanks in advance.

 

[Topzide]

@Stranger, Here's a site that will have the answers you seek; https://www.the12volt.com/
It'll help with all types of wiring. The relay would be the best and then if needed, you could have the relay activate a solenoid to handle the power if needed for the other circuit. Hang in there, you'll get it figured out. I picked up a Power Pole tester for wiring and love it! Has enough cord to go bumper to bumper on my truck! Good hunting.