Lock Up Converter Vacuum Switch FAIL???

[chengny]

You cannot buy a GM tcc switch anymore.

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Nalley and Rockauto has them:

http://parts.nalleygmc.com/products...ter-Transmission-Vacuum/2681523/14032087.html

http://www.rockauto.com/catalog/moreinfo.php?pk=86939&cc=2793

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Apparently they came mounted in various places. Some applications had them on the firewall over by the master cylinder:

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They were also mounted on the RH side, as shown in the dwg above.

 

[HotRodPC]

Rock Auto has the AC Delco Switch, ACDELCO Part # 212331 For $60.
I'd prefer to get one at the local DIY Parts Yard. I know I'll be picking up a couple next time I go and not Tip In switches like I had gotten before.

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[HotRodPC]

Oh, I see Chegny was posting it as I was looking it up.

 

[VAL]

Ok, so I disconnected the plug(terminal) at the tcc vacuum switch, I put the key in the on position, put my voltage tester on it, and I have 12 volts on one of the wires. Can I temporarily bypass the vac switch with a toggle switch inside the cab to test it and see if the lockup is working? or is there something I'm missing before I get on the freeway and turn it on at cruising speed?

 

[HotRodPC]

Sure, you can hit the right wire in the 4 prong plug in activate the lock up. That's how it was done back in the 80's when guys did retrofits. They also tore up alot of converters forgetting to shut it off coming to a stop. You'll also lose the feature to unlock when you step down on the throttle or climb a hill. Just keep all that in mind and go for it.

 

[VAL]

I just want to see if it works, If it does, I'll order a vacuum switch from rockauto, to have it turn off and on automatically. If it doesn't I'll have to do some more troubleshooting. Just worried cause it hasn't been turned on in many years.

 

[HotRodPC]

I just want to see if it works, If it does, I'll order a vacuum switch from rockauto, to have it turn off and on automatically. If it doesn't I'll have to do some more troubleshooting. Just worried cause it hasn't been turned on in many years.

Not a bad idea. It's a pretty simple set up. Provided all the wires are good, not grounded out, cut up and all in good shape, the vac switch and the lock up solenoid in the transmission is all there is to it. The TCC won't go bad by not being used, and it should stay in good shape being it's sealed inside the Torque Conveter, so if the Solenoid in the trans is working and your wiring is good, I see no reason it shouldn't work.

 

[VAL]

Not a bad idea. It's a pretty simple set up. Provided all the wires are good, not grounded out, cut up and all in good shape, the vac switch and the lock up solenoid in the transmission is all there is to it. The TCC won't go bad by not being used, and it should stay in good shape being it's sealed inside the Torque Conveter, so if the Solenoid in the trans is working and your wiring is good, I see no reason it shouldn't work.

Thanks HotRodPC, I'll keep you posted and see how it goes. Your one hell of a motivator.

 

[VAL]

Not a bad idea. It's a pretty simple set up. Provided all the wires are good, not grounded out, cut up and all in good shape, the vac switch and the lock up solenoid in the transmission is all there is to it. The TCC won't go bad by not being used, and it should stay in good shape being it's sealed inside the Torque Conveter, so if the Solenoid in the trans is working and your wiring is good, I see no reason it shouldn't work.

Isn't there a pressure switch also?

 

[HotRodPC]

yes, that is also true. Pressure switch is activated when the trans in 4th gear. Sometimes even have a 3rd and 4th pressure switch so it can lock up in 3rd too.

 

[VAL]

If its not one thing, its another. So today I went and bought a toggle switch to bypass the vac switch, I go to hook it up, now there's no power going to it at all, when just yesterday my meter was reading 12volts on it. Upon further inspection while I was under the truck, I happened to pull out the 4 prong connector and look what I found.

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[MadOgre]

Ah nice!

I grabbed an actual TCC switch off the passenger side firewall of an 85 with a 305 and it was located in exactly the same spot as HotRods pic. As you all have probably noticed already they do look different from the one in HotRods pic.

 

[VAL]

I need to figure out where the power comes from that goes to the vacuum switch now. I checked all my fuses, and they are all good. This thing is really starting to piss me off, Just last night I had full power to one of the wires of the vac switch, all of a sudden I ain't got nothing.

 

[MadOgre]

I would like some info on what and which wires go where too. I had a 6.2 diesel and I need to wire it up the gasoline way. I assume it is the same but I don't know as I never gave it a second thought when I was pulling out the diesel cause I had the th400 then.

 

[VAL]

I would like some info on what and which wires go where too. I had a 6.2 diesel and I need to wire it up the gasoline way. I assume it is the same but I don't know as I never gave it a second thought when I was pulling out the diesel cause I had the th400 then.

HR or Chengny will have to chime in on that one.