Brown wire mod ?

[deancam]

Hi everyone.
I did the brown wire mod a few weeks back and used a lighted switch on the dash. When driving with the transfer case engaged in 4HI or 4LOW, the light on the switch brightens up for most of the time but flickers sometimes while driving over obstacles. I can feel the CC disengaging and engaging. This tells me that the computer is still controlling the clutch coil. I thought the module only controled the CC in the AUTO setting and in 4HI and LOW the CC is always locked. If this isn't the case then there really isn't a true 4wheel drive setting.

Anybody experienced this?
maybe just me.

 

[gijoecam]

The GEM will still vary the duty cycle of the system, even in 4high and 4low, but generally, for all intents and purposes, it's locked. When stopped or crawling, the system reduces power to the TCCC, but it should still not slip significantly, and should ramp up the duty cycle as soon as you start moving.

Completely normal. I don't know how it was programmed, but I'd love to learn more about the actual program (I'd like to meet the guy that developed the system some day, and both shake his hand and smack him for it!!)

-Joe

 

[deancam]

Thanks for your reply Joe,
I just find it annoying that the GEM decides to unlock the CC periodically
while wheeling, even if only for a second or two, just a perk with having the control-trac system I guess. It doesn't seem to interfere when driving straight, only when turning or when a wheel spins........great!. I just sold my old 4runner about a month ago, when you put it in 4wheel drive it was in 4wheel drive.
When I was wiring the switch for the mod I checked the voltage on the wire coming from the GEM. It was something like 5.3 volts. I wonder if you could bypass the GEM and just run this voltage to the CC so that you could have full control of the CC. Maybe this has been discussed already
on this forum, I couldn't find anything.
???

 

[gijoecam]

It's certainly been discussed, and it's what would need to be done on a 95 or 96 to provide it with true 4high. If you read through the portion of the Comprehensive Brown Wire Mod thread that deals with the 95-96 system, I think I explained it in there.

The short version is, yes, you can do it that way. I initially had my 98 wired-up the way you described just as a proof of concept. I used a DPDT on-off-on switch, and drew one power source from the original brown wire, and one from the auxiliary power point. It was more for proof of concept than anything, as the 97-01s have a true 4high (as you know).

Now, as for the wiring, it's a good idea to use a switched source, otherwise the TCCC will still be powered when you turn the key off. I doubt it would hurt the TCCC, but at the very least, it'll kill the battery overnight. I don't know of any good high current switched circuits you could use offhand. I would suggest using a relay, feeding the TCCC from the aux power point, and using the switched power source to trigger the relay. Make sense?

Good luck!

 

[Fredness]

Mine was pure overkill on my old '97 OHV Control-Trac (my current '98 is 4x2).

I used a small 12v light -up rocker (Red=Off like a gun safety, red you're dead) and that was connected to the coil of a 30 Amp Bosch Relay. The relay was a Normally closed relay so that with the switch off, there was a "TCCC ON" signal present.

With the switch on, there was power to the coil, opening the relay to no connection (TCCC-Off).

Now, the relay was powered by the radio circuit for troubleshooting (I don't drive any where without a radio!) and the "Holy Crap" mode (everything fails, bad switch, no power, bad realy) is TCCC on.

Worked like a champ and allowed me to use BFG MT/KO's on the front without any harsh noise on the street. Otherwise, the CV's complained LOUDLY...

A really nice plus is the ability to use "2LO" (4LO with TCCC off) when towing a camp trailer off-road. Wow...

 

[deancam]

thanks guys,

i'm going to wire it up the 95-96 method with the on-off-on switch as recomended. Like the idea of bypassing the GEM.

really loving this forum, lots of great info!

Purchased my 97 about a month ago, already done the TT-war153-aal lift, throttle cable mod, BWM, checked the TPS and cleaned the maf.
Runs like a top! Now if I could just get that gas mileage up a bit.
Gets between 14-15 a gallon but that sounds like its normal for mostly city driving. Not complaining.

cheers.

 

[gijoecam]

Just something I forgot to mention... if the transfer case is slipping in 4low and 4high, I'd suspect it's more likely a mechanical problem with the case itself. I'll be interested to see if the symptoms you mentioned disappear when it's manually locked.

 

[Raminator157]

try asking questions in this existing thread. it will probably help you more http://www.explorerforum.com/forums/showthread.php?t=147419&highlight=Brown+Wire+Mod