Wow.. my quote was insightful... brings a tear to my eye.

 

Makes me laugh everytime I read it. Now I'm waiting for something along the lines of:

I did buy a set of male and female spade bits that I thought were small enough to make jumpers with. They are not, so I will continue looking. My main opjective is to fashion three short jumpers that go from the actual pressure switch plug to its connector. Then I want to disconnect just the ground wire and see where that gets me. If it works alone to disable both systems, I will wire the factory switch inline and see if a mommentary interrupt of the ground wire will accomplish the same thing.

Andreas

 

A new week. Another chance for a solution. Any new findings?

Andreas

 

Well, I managed to get the three jumpers to work for me. I had to actually cut the female spade bits down in size so that all three would fit within the confines of the pressure switch. I also gave each ending a small wrap of electrical tape. On the connector end of things, I found male connectors that were round, almost like a banana plug. I flattened the ends of these and filed them slightly so that they would fit into the connector receptacles. I started the truck, and then pulled the Ground wire (red). TRAC, VCS, and ABS shut down. This confirms that we can easily and safely wire a normal on/off rocker switch in line with the Ground wire. This will not allow the use of the factory TRAC OFF switch, but it is a solution.

Coda,
You stated the following:

What is a latching relay? Would a latching relay and the TRAC OFF switch work with what I described above? I guess the TRAC OFF switch is normally 'open' and only closes when depressed. If you want to try your theory out with a factory TRAC OFF switch, I'll gladly mail it to you to try. Please let me know.

Andreas

 

If integrating the factory TRAC OFF switch will not work, another option is to get clean black on/off SPST rocker switches with one of the following symbols already imprinted:

Rocker switch symbols

I spoke with this company and they only sell through distributors. If we went this route, I would handle getting an order placed - they have a $100 minimum. Check out: "4/2WD Lock," "Ride Control," and "TCS" (Traction Control).

Just another thought.

Andreas

 

I found my old factory fog light switch (non-illuminated) and have put together a nice little harness with shrink-wrapped connectors, etc. I used 18 gauge wire, as that's what the connector at the pressure switch appears to use. Tomorrow I intend to snip the ground wire (red) and splice in my harness. That should give me the ability to switch off TRAC/VSC/ABS at the flick of a switch. Just like I wanted. From this day forth, this will officially be known as the "AndyMod".

When Coda/Ducky/etc. figure out a way to employ the factory TRAC OFF switch, I will swap methods. Until then, it's the AndyMod.

Andreas

 

Wheres the pics?

lol

So let me get this straight, you do or do not have to turn the vehicle off and on everytime you make a change?

 

Ducky,
TRAC/VSC/ABS will be shut down when I flip the switch (ON) - with the truck on or off. I'm simply breaking the ground connection.

In order to regain the systems, I'll need to flip the switch again (OFF), to re-establish ground, and turn the truck off and on again. I think this will work perfectly fine for most situations, as the actual need to kill the systems happens on rare occasions. For example, I'm in a muddy situation that requires full-on wheelspin. I flip the rocker switch, killing TRAC/VSC/ABS. I power my way through the mess (slinging crap left and right). Once I'm clear, I simply flip the switch again, turn the truck off, and turn it back on. Viola! The systems are back in order.

I'm still waiting to see what Coda99 comes up with, as I'm not ruling out the usage of the TRAC OFF switch. It sounds as if he may have a grasp on how this can be done. Until then, I'm spinning tires - when I want to!!

Pics to follow...

Andreas

 

Hey Andreas

I found the type of relay needed to make the factory switch work. Go to www.alliedelec.com and do a search for part # 850-5071. Open up the pdf for the catalog page 826. The class 388ML single coil latching relay (12V) will work for the application. But, I think I could wire up the dual coil relay (part #850-5073) to reset when you turn the ignition off. Just not exactly sure how this relay works yet. Have to get my hands on one. If you need a schematic on how to wire these all together I will draw one up and try to post it.
If you still plan on using the wires on the master cylinder pressure sensor I would use a bit of caution. If you notice on the schematic these wires are shielded. Depending on where you tie into them I would also use a shielded type of wire.
Later

 

Coda,
That seems to be great news. Unfortunately, I am not versed in what 'latching relays' do, or how they do it. It would be great if you sketched a diagram of how you feel this could work. I presume you are including the factory TRAC OFF switch, the relay you found, and the ignition wire (#D7) at the VSC ECU?

As for shielded wires, what exactly does that mean? I know my way around home wiring, yet shielded automotive wiring is not something I'm familiar with. The three thin wires that make up the pressure sensor connection appear to be common 18 gauge wires. I know the schematic mentions it, but how does one tell shielded from non-shielded?

Also, my offer still stands:


Andreas

 

Andreas
If we are looking at the same harness on the schematic ( labled M4 with wires VCM, PMC, and E2) these look to me as low voltage data wires ?. If they do carry data info the shield would help eliminate any outside noise that might corrupt the information. Not trying to tell you what to do, just want you to know what might happen if there is no shield. Better safe than sorry.
Later

 

Coda,
Thank you. I may hold off on my install until you get further with your theory. Let me know if yoiu want to use my TRAC switch.

Andreas

 

Coda,
Although the diagram shows all three to be shielded, do you feel the same caution applies for the red ground wire?
If I try this and somehow the TRAC/VSC systems fail to come back online due to electrical interference, could I safely splice the cut ground wire back together?

Andreas

 

Ducky,
Since you had to ask:





Andreas

 

Man, REVOs sure have a distinctive smell!! I can't remember the last time I left a patch as impressive as today.

Oh, I almost forgot - the first official ANDYMOD™ is in place and works like a charm. I did a nice clean install of the mini harness I made. I can defeat TRAC & VSC at will, whether the truck is standing still, going 60 mph, or completely shut down. To regain the systems, I simply flip my rocker switch back to the 'off' position and restart the truck. All systems are then back on line.

I realize that this may seem cumbersome to some of you, but the sheer ease of install, coupled with the ability to control when and for how long I spin my tires - is priceless! I never knew that my truck had enough Ummph to sit at a standstill, powerbrake, and leave Bridgestone's finest on the pavement for local admiration. Suffice it to say, my switch will be in the Off position 99% of the time - REVOs are just too damn expensive

If anyone gives a cat's turd, I can do an easy writeup. Otherwise, I await the wisdom of Coda99 and his potential usage of the factory TRAC OFF switch and a latching relay. When he gets that figured out, I will quietly undo my wiring harness and install the proper switch.





Andreas

 

Coda99,
Since we discussed it earlier, I found that the actual wires that connect to the pressure sensor are non-shielded. A few inches back from the connector, they are wrapped in a shielded covering. So, they are shielded, but not individually.

Andreas

 

If you're willing to do the write-up, I'd like try it out since it meets the primary objective.... defeating A-Trac. If you'd rather not, I'll just wait till Coda99 kicks in with his results.

The ability to enable VSC/A-Trac without restarting the truck is definitely more ideal, but I could manage without it....

 

Scott,
I'll do a write-up on the ANDYMOD™ when I get back on Monday - leaving in a few hours for Florida!

For the basics, I just used a nice on/off rocker switch (my old factory fog light switch), ran two legths of 18 gauge wire through the firewall grommet to the master cylinder, and then cut and spliced these into the red (ground) wire at the pressure sensor connector.

Works perfect. We are getting snow right now and I turned it all off and did some nice juvenile donuts. The center diff lock still works as designed. Just like I wanted it.

In retrospect, a pushbutton switch would word just as well, as long as it is constant power otherwise. The ground only needs to be interrupted for a split-second to shut the systems down.

I'm happy.

Andreas

 

Finally made up a quick schematic of how I plan to wire up a relay using the factory switch. Just not sure how to post it on the site. Would be more than happy to send it by E-mail.
Later

 

Coda,
Send it to me and I'll post it here for you - aowalter@comcast.net.
Congrats on moving forward!

Here goes:





Andreas