Can't get the steering wheel controls to work with the Pac Swi-X controller

[Dark Ride]

So I finally got the car stereo in my TGP and got the Pac Swi-X wired up to make the steering wheel controls work and I can setup the interface number, but when I go to start actually programming the controls and remote together, it doesn't recognize that I'm pushing the buttons on the steering wheel controls.  I set the interface version to 10 and used the yellow wire per the instructions.  I tried two different sets of steering wheel controls and got the same results.  Has anybody had trouble with these? Also, does anyone know if there is a way to confirm the controls are working properly?  Thanks!

[GabsOlds]

Is it possible the clock spring is broken? Besides the horn, I don't know if there is a quick way of confirming the clock spring works.

[vipmiller803]

The horn doesn't use the clock spring...

 

I used the PAC adapter and it worked fine. You could measure resistance between your wire and ground while clicking buttons. I believe that is what changes. Honestly do not remember wire colors as it has been a couple of years, but obviously make sure the yellow one is the correct one. I remember the instructions being a slight bit redundant and me having to do a minimal amount of trial and error.

[Dark Ride]

I'll try measuring the resistance between the data wire and the ground this afternoon. I do know there is voltage on the data line. Any idea on how to check clock spring/turn signal switch? There is also a small circuit board/module inside the column that takes the signals from the buttons and outputs to the data line. Anybody ever have that go bad?

[Heartbeat1991]

I thought it was a green wire it connected to.  I will have to go take a look at it.

[Dark Ride]

I was just thinking about this, if my data line has voltage I can't check resistance, I'm thinking it probably sends a wave signal and I don't have a scope.

 

Heartbeat if you can check yours that would be awesome. The data line on the car was green. But the wire on the adapter was yellow. The 89 to 93s should all be the same. Also, what interface number are you using? It should flash the interface number when it first turns on. The left led indicates tens and the right led indicates ones. I.e. 10 is the left led blinking once.

[GabsOlds]

When you push the buttons to close circuits, you measure voltage between wires, not resistance. 

[Imp558]

I believe Miller is correct, you would disconnect the wire that goes to the wheel from the PAC and measure resistance to ground while pushing buttons. Each should be a different resistance.

[Dark Ride]

Everything I've read says you cannot test resistance on a live circuit as you can ruin your multimeter and there is voltage on the data line.  Is there something I'm missing?

[Imp558]

disconnect the wire that goes to the wheel from the PAC

[Dark Ride]

I disconnected the data feed wire from the wheel to the pac. There is still voltage. 10.50 volts, it does drop down to 10.47 when a button is pressed and held. Not sure if that helps or not.

[jman093]

I think you're going about this the wrong way. I don't think the SWRC is a multiplexed signal where that could be checked by measuring voltage or resistance with a voltmeter. The only thing you could really check with a multimeter is measuring the resistance of the wiring to check for any broken connections, but that's not likely your issue. As mentioned, there is no clockspring. The SWRC switch assembly "talks" to a small module under the dash through an optical signal / photocells in the column under the steering wheel. There is no physical connection. The signal is coded in optical light transmitted by photocells. It will be an analog or digital message of some kind, not some particular voltage/resistance you can check. Same thing with the module "talking" to the head unit. It's going to be a bussed message to another module. GM sent special a Kent-Moore tool kit to diagnose SWRC issues. It replaces components in the system to isolate the problem, since you can't measure anything. I have a kit at home. I'll get the number later. They can be found pretty cheap on ebay IIRC.

 

Has there always been an aftermarket head unit in the vehicle? If not, did the SWRC work with a factory one? If it did, you're obviously fighting some compatibility issue with the PAC and you're wasting your time diagnosing the vehicle.

 

If there is a problem with the vehicle SWRC, in my experience it is most likely with the optical photocell setup. It doesn't work that well. GM released a module with higher signal gain that supposedly works better, but I don't know if it fixes anything or if you could even find one nowadays. I'll try and get the part number later. My DD TGP works intermittently when the wheel is in certain positions, most likely when the photocells are best lined up. I've tinkered with it some and never gotten it to work reliably. My black TGP worked great until I put an aftermarket turn signal switch in it. Certain buttons works, others don't. I think there is some signal loss in the aftermarket switch.

 

Hope this helps.

[Dark Ride]

That helps a ton. When I got the tgp there was no radio, but someone had put in an aftermarket deck because the aftermarket bracket was still there, so i have no clue. Now I'm suspecting the light cell switch as well as that seems like the weakest link. If you can find the part numbers for the tool and the upgraded switch that would be awesome, then I can see what I can find.

[Heartbeat1991]

I have an SWI-PAC.  The yellow wire from the PAC should go to the green wire on the radio harness.  The SWRC has it's own connector.  I'm almost positive it was a green wire.

[Dark Ride]

Alright, so that is the same way I wired it then.  Starting to think more and more that this is a problem with the controls themselves.  I was looking at the wiring diagram, and the diagram lists the turn signal switch and cancel cam assembly as two different pieces.  I can find aftermarket turn signal switches but nothing is listed for cancel cam assembly.  Is this one piece or is there another part I would need.  I haven't been able to find a true GM switch.

[Nas Escobar]

https://www.amazon.com/ACDelco-26047013-Original-Equipment-Signal/dp/B000IZ3MJS

 

That is the cancel cam. It is simply a piece of plastic that goes behind the compressor plate. If your turn signal switch is not factory then you need to make sure that it was the one with the swrc function. Theres 2 of them. Rock auto sells the non swrc one for $50 and the swrc one fo $100 iirc.

[Dark Ride]

Thanks for the info! I haven't taken one of these columns apart before so I'm trying to learn as much as I can before I start. The cancel cam doesn't have anything in it then that would fail in regards to this, so unless I'm mistaken if the controls aren't working its either the buttons, the turn signal switch that contains the photo cells, or the circuit card that outputs the signal to the head unit.

[jman093]

Actually, on a SWRC car, the cancel cam is a part of the system. It has some contacts on it that are used, and IIRC, one set of the photocells is on it as well. GM labeled it a "Circuit Board and Turn Signal Cancel Cam." That amazon-linked one will work on practically every Saginaw-column GM car back to the 60s, unless it has SWRC. The GM part number is 26009372 and shows discontinued. No idea if aftermarket makes one.

 

The diagnostic tool for SWRC is Kent-Moore J37608 and the J-37608-92 adapter. Looks like they can be had for less than $20 on ebay.

 

Here's a copy and paste the of bulletin I mentioned as well:

 

#90-3-18: STEERING WHEEL RADIO CONTROLS INTERMITTENT OPERATION - (Aug 28, 1990)

Subject: INTERMITTENT OPERATION OF STEERING WHEEL RADIO CONTROLS (REPLACE BRUSHES/SPRINGS REVISED MODULE) Models Affected: 1988-90 GRAND PRIX MODELS

Condition:

The radio controls located in the steering wheel pad may work in- termittently. The buttons on the radio receiver can still be used to control the radio functions.

Cause:

1. There may be a corrosion build up between the turn signal switch brushes and springs because of the plating process on the brushes.

2. The translator module located at the base of the steering column may be misinterpreting the signals from the steering wheel pad. A revised translator module with a higher electrical gain is available from GMSPO.

Correction:

1. Replace the brushes and springs in the turn signal switch using kit, P/N 10456442.

Labor Operation Number: T1413

Labor Time : 0.5 Hour

2. Check to see if the translator module is an old version with a white date code stamp. If the color of the stamp is white, install a revised module, P/N 26014179 in the vehicle. The new part received from GMSPO should have a blue stamp on it.

Labor Operation Number: R0745

Labor Time : 0.5 Hours

Parts are currently available from GMSPO.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.

[Nas Escobar]

 

Actually, on a SWRC car, the cancel cam is a part of the system. It has some contacts on it that are used, and IIRC, one set of the photocells is on it as well. GM labeled it a "Circuit Board and Turn Signal Cancel Cam." That amazon-linked one will work on practically every Saginaw-column GM car back to the 60s, unless it has SWRC. The GM part number is 26009372 and shows discontinued. No idea if aftermarket makes one.

That's rather odd... my 94 column has that cam and it was there before i swapped the ts switch. My car was factory equipped with the swrc but i practically deleted it with the aftermarket steering wheel and non swrc ts switch.

[jman093]

That's rather odd... my 94 column has that cam and it was there before i swapped the ts switch. My car was factory equipped with the swrc but i practically deleted it with the aftermarket steering wheel and non swrc ts switch.

94 is a completely different setup utilizing a clockspring. This is for 88-93.

[Nas Escobar]

94 is a completely different setup utilizing a clockspring. This is for 88-93.

94+ had a saginaw correct? I remember someone stating that 88-93s don't have a saginaw based column

[Dark Ride]

I bought the SWRC tool to diagnose the problem.  Hopefully its something that I can still buy.

[Dark Ride]

So, updating this thread.  The tool confirmed it was in the turn signal switch/cam.  I was able to buy the new switch but of course it doesn't have the turn signal cam that spins with the steering wheel and has the connection for the controls/horn.  Does anyone know if you can still buy them new and if so where?  I'm pretty sure mine is junk...

 

Also, does anyone know what the thread size is on the steering wheel shaft?  It looks like some cross threaded it at some point and I would like to buy a new nut and clean up the threads with a die.

[Dark Ride]

I'm guessing that unless I stumble on one on eBay or something I'm not going to find one new. Does anyone have one in good shape they'd be willing to part with?

[jman093]

So, updating this thread.  The tool confirmed it was in the turn signal switch/cam.  I was able to buy the new switch but of course it doesn't have the turn signal cam that spins with the steering wheel and has the connection for the controls/horn.  Does anyone know if you can still buy them new and if so where?  I'm pretty sure mine is junk...

 

Also, does anyone know what the thread size is on the steering wheel shaft?  It looks like some cross threaded it at some point and I would like to buy a new nut and clean up the threads with a die.

 

Did you install the new switch? It's hard to see the cancel cam going bad. I posted that TSB from GM back in December of 2016 detailing SWRC issues. The first mentioned poor contact between the brushes and springs causing poor or no operation of SWRC. I have personally seen this happen. Try the new switch. You are WAY more likely to have a poor connection with those brushes and the switch than the brushes and the cancel cam, especially since the brushes are always sliding on the cam, corrosion doesn't build on that end like it does on the switch end where the springs sit. And is the new switch ACDelco or aftermarket?