Re-hook up of lock up converter

[steve3408]

Heres my question, on a 1984 C-10 silverado, came with 305 from factory,someone has changed it to a 350,aluminum intake and hi perf distributor (4 wire ? ) the wire plug ins for the transmission (turbo 350c) are still there but not hooked up for the lock up torque converter to do its thing, i'm guessing because of the aftermarket intake and vacuum lines and maybe the distributor not being the type that has 2 sets of wires that connect up to the wireloom as originally set up.Whats the best way to make the lock up torque converter work right again,it should help at highway speeds and gas mileage a little,is there a fairly easy way to do this or should i get the B&M kit to manually engage it??

[y2k_harley]

My 86 is in the same situation.  It had a 305 with a turbo 350c.  The engine had been switched out for an older 350 and the transmission is now just a regular 350.  Is your tranny still a lock up tranny?  Might have been replaced at some point.

[Lt.Del]

It's easy to tell if it is a lockup TC because it will have the wire plug on the left side above the pan.  I put a th350c in my 79, which, of course, didn't have lock ups back then.  I have a toggle switch going to mine that I control from the dash.  When I am on the highway, i flip the switch and watch the rpm's fall.

[VileZambonie]

did you try plugging it back in first?

[steve3408]

I did try just plugging the connectors back on the trans. couldnt tell it made any difference, i think the factory set up gets signals from the distributor and vacuum modules that were on the stock intake.With that stuff being changed around i'm not sure what it would take to get it working again.B & M makes a kit to manually switch it, but its kinda pricey.

[Lt.Del]

Radio Shack $2 toggle switch.  At least, that is what I do.,

You are right about the distributor, vacuum, and brakes having a switch that overrides the lock up feature.  But I didn't bother with all that.  I have found that when my lock up is switched on, and I slow down quickly, it still frees up the TC to slow down and it I frequently come to a stop without problem even when the switch is on.

[VileZambonie]

do a search on here for tcc solenoid. Lots of info on different ways you can wire it. the problem with a toggle switch is you better make sure you turn it off every time you hit the brakes or decel or accel.

[Lt.Del]

Vile, that's what i thought.  I used to use it only while on the interstate and the switch is close to me.  But, I have found out that I have no problem slowing down or coming to a stop even when the switch is on. It kicks out of the lock up feature automatically when my rpms go below a certain level. My truck is possessed.  It knows when I am slowing down.

Acceleration is an issue though.  When I want to pass someone, I flip the switch off.   

[user85]

i have an 85 c10 with a 350c the only thing under the hood that controls the lockup is a vacuum switch on the firewall next to the brake booster. I have mine hooked to ported vacuum when you let off the gas it disengages. The wiring from this switch goes to the trans and inside the cab to the fuseblock. It is a green wire I think that plugs in where it says accessory and   the brake light switch is included in the cab wiring also so when you tap the brake it disengages also. I just went through this with my truck and i can help more if needed.

[choptop]

Will this help?

[Captkaos]

http://www.73-87.com/7387garage/drivetrain/lockup.htm

[steve3408]

Thanks to all this has given me some great info. to work with, crawled under it today and looked at the 4 pin switch, and its got black silicone smeared all over it...?? kinda like "capped off" i dont know why in the heck they did that.So now i'm going to pull the pan and see it it still has the wires going to it,and if so  put a new connector in there so i can hook up the external wires to it.I guess thats the place to start.

[Lt.Del]

mine is a 2 pin connector, but most are 4 pin connectors.  You can go to a salvage yard and pull dozens of those off since they were so plentiful.  Pull one off an old tranny and clip the wires--don't clip wires too short.  You'll then have a plug to splice the wires to.