wiring to torque converter solonoid

[john robertson]

I noticed last night my torque converter was not locking up. I know it was working rather recently, so it's not something that's been going on for a long time and I wasn't aware of it. I checked today to find out the wire that plugs into the transmission that powers the lock-up solenoid is not hot. A few years ago I put a switch on that wire so I could select whether or not I wanted the converter to lock. I use it all the time. Is that wire fused? Where does it get it's power from? Can I just power up the lock-up solenoid by putting 12 volts to a switch wired to the solenoid? I would have tried this already but I have to move some wires around to do it, so for now, it's easier to ask first.

[earlbrown]

There's a wire on the ALDL plug you can ground to lock up the converter.

The way it's wired (when it's working correctly) is the brake pedal has a switch that sends power to the TCC.  As long as the pedal is not pushed (or the switch is slid back) the TCC has power.

The ground path starts at either the 3rd or 4th gear NC switches on the transmissions valve body.  When in 3rd or 4th, the switches send a ground to the ECM.  Then the computer decides when it wants to send a ground to the TCC.


  Grounding the ALDL takes the ECM out of the loop but the brake pedal can still unlock it.

[john robertson]

Yeah, I have that mod, and it worked, but that's not the problem I've described. No power to the lock-up solenoid.

[nocooler]

Earl just told you how the circuit is supposed to work. Check the fuses, and then the brake switch. We have a link to a copy of the service manuals for http://www.ihadav8.com/forum/index.php?topic=6406.0

[Steve Wood]

http://www.vortexbuicks-etc.com/tcc_lockup.htm

[john robertson]

Thanks! Will check the fuse first this morning. Hope that's it.

[Steve Wood]

Earl just told you how the circuit is supposed to work. Check the fuses, and then the brake switch. We have a link to a copy of the service manuals for http://www.ihadav8.com/forum/index.php?topic=6406.0

I don't believe the gear switches have anything to do with converter lock up.  Pretty sure they are used to invoke fueling tweaks for EGR ??

[nocooler]

Looking at the diagram you are right. Ground goes right the ecm @ A7

[john robertson]

Good for me to now know that there is a fuse for the TCC solenoid as per the Vortex troubleshootin g guide (thankyou!). I replaced the fuse and established power to the solenoid. Went for a test drive but it still didn't lock up, and thought I had re-blown the fuse, but when I came back I discovered it was not blown. At this point, I think I have to replace solenoid. I'll test some more to make sure before I do.

[Steve Wood]

If you have power on the purple wire at the transmission, it would appear to be the solenoid.  If  no power at the transmission, it would seem to be the switch on the pedal.  Just have to follow the winding road

[Forzfed]

When I put a bottom feeder filter in the transmission I pinched the feed tube against the wire and lost my lockup and AC!

[john robertson]

If you have power on the purple wire at the transmission, it would appear to be the solenoid.  If  no power at the transmission, it would seem to be the switch on the pedal.  Just have to follow the winding road

OK ... I resolved the issue on my GN. It was the blown fuse after all. I went on a longer loop to test it and it IS going into overdrive, at least for now. I'm saying that because I don't know why the fuse blew in the first place, and, who knows, it could happen again.  Anyway, I've been driving my turbo elky for quite some time without lockup. I replaced the TCC solenoid some years back but it didn't fix it, and I just said to hell with it. So now, with this new found knowledge  , I checked the fuse, and it was not blown. The damn thing wasn't even there. I installed one and also, the pedal switch button was not even touching the brake pedal shaft. Fixed that, and it's working as it should, but still no lockup. I'm going to have to go to the trans plug and check to see if there voltage there. Not sure when I'll do that. I was more concerned with the GN. The Elky? I'll get to it. Thanks all of you for your help.

[Steve Wood]

that Elky is sweet!  Glad we helped you get one done!

[john robertson]

that Elky is sweet!  Glad we helped you get one done!

Thankyou! I'll get around to it when I feel like jacking it up.