tcc circuit

[ctadams21]

Just checking out the wiring diagrams for the tcc and I am a bit confused.
The regular s10/s15 with a 4.3 and 700r4 has three wires to the tcc: lt blue(446), tan/blk(422), and ppl(420).
The syclone diagram only shows the tan/blk and ppl. The diagram of the tcc circuit is identical on both the syclone and s10 diagrams. The only diffence is the lt. blue signal wire. How does the syclone accomplish tcc engagement (under the speed, temp, gear criteria) with only two wires.

The reason I ask is because my trans and truck is s10, motor is syclone.

Thanks,

CTA

 

[Daryl H]

I show the TAN/BLK and PPL wires used in 2.5L and 4.3L applications.
The LT BLU is used only on 4.3L.

 

[leroy]

My question is what is the 3rd wire for? A spring loaded solenoid can be controlled easily with 2 wires. The ecm can tell if it's engaged by looking at speed and rpm.

Jim

 

[Daryl H]

Maybe another circuit to open up the TC so it will free wheel in 4th gear coasting?

 

[Loeryder]

I asked a good friend of mine about hte third wire and he says:

the blue wire does nothing. It can be physically cut off and
won't do anything.

He went on and on about the solenoids and what wires do what, but I'll jsut answer the simpler question at hand.

 

[sytyguy]

I wired my '64 Chevy II this way (w/o the 3rd wire). The circuitry inside the case is only 2 wire (up to the switch), so I figured the 3rd wire was pointless. FWIW, I wired mine up per Bowtie Overdrives' diagram.

Hood

 

[ctadams21]

Strange that the s10 would have an extra wire but it sounds like I won't be needing it anyway. I guess as long as I wire it per the SY diagram it should be fine. Thanks all.

 

[jwaller]

the third wire was supposed to be for daytime running lights. it was never used.