Chillin green wire with orange connector

[North Central Ohio]

One thing that's been buggin me off and on for quite a few yrs is a green wire w an orange connector that's chillin above my break booster on my '86 Chevy Silverado w a 305 and 700r4 trans. It connects to the pigtail on the side of the trans.and I've heard numerous times that it's a test connector. I tend to believe this after seein it many times,but could someone please explain how this connector works as far as what it tests? It drives me nuts havin a connector that isn't connected,unless it's there if need be. Thank you in advance!

[hatzie]

It's the diagnostic wire for the lockup torque converter.  You can find them on trucks with the TH350C too.

[North Central Ohio]

Thanks for the response hatzie. I think I was too vague w my question though. Is it kinda like an ALDL for the converter where,when hooked up,it gives trouble codes or somethin?

[bd]

It is used to monitor application voltage to the TCC.  There are no transmission specific diagnostic codes associated with the 4L60 (700R4) transmission.

[VileZambonie]

Does your truck have the ALDL under the dash?

[hatzie]

Thanks for the response hatzie. I think I was too vague w my question though. Is it kinda like an ALDL for the converter where,when hooked up,it gives trouble codes or somethin?

The TH700R4 / 4L60 doesn't have a TCM.  The test wire should have + voltage when the ignition is on and the TCC brake pedal switch and TCC vacuum switch are passing volts to the Torque Converter Clutch engagement wire on the transmission.
There's no Serial data stream like CLCC, EDC, TPI, and TBI sent out through the ALDL data port under the dash.

Does your truck have the ALDL under the dash?

I'm interested to know...  The wiring diagrams from 1982 on show ALDL ports in the wiring.  Up to 1986 I believe that would've been CLCC (Closed Loop Carburetor Control) on the 1/2 tons only unless someone retrofitted TBI or TPI.  Whether the ALDL ports were present or not is an open question.  I never looked for one on my 1985.

[VileZambonie]

If it has California emissions it should have the ALDL and ECM

2WD
4WD

[North Central Ohio]

Ok. That's understandable. No...my truck doesn't have an ALDL. I was just wonderin how "specific" of info that test connector would provide. Thanks for the info. I can deal w it just bein a dangler then.lol