TCC Electrical Question 350C vs 200-r4

[tomard]

My car (1980 Chevy Corvette) currently has Th350c (lockup) tranny. Lockup is controlled by a manifold vacuum switch, that then is connected to tranny, to lockup tcc.

When I install my 200-r4 (4BQ), will I only need to connect my electrical connector that is currently plugged into 350C, to new 200-r4 connector, or is there any wiring tasks that need to be done, connector changes, etc to get lockup to work as it did with 350C????

[jmd]

the 200-4R connector is
A [12v from brake switch to TCC solenoid]
B [ECM]
C [not used]
D [from ECM ground to TCC solenoid]

I know the 700 connector is the same as the 200-4R but I haven't looked at my TH350-C in a long long long time.

[tomard]

Since the 80 does not have ECM, I am still kind of at a loss here. I would think with as many conversions that have been done to 200-r4, that there had to be some from Th350c's and the lockup issues that come with that conversion (if any).

Just want to be prepared when I bolt up the 200-r4

[jmd]

I just thought of something. 1983/1984 SS Monte Carlo accepts a direct swap of a 700-R4 or 200-4R. No changes needed for lockup.

If the 1980 TH350-C has the same connector, I'd say you're good to go. Your vac. switch wire probably goes to D.

Got a svc. manual for the '80 or have you dropped the pan?

[tomard]

Here is illustration from shop manual ... doesn't show anywhere what wire does what ..... I will confirm the connector, but I am pretty sure they are same.

[jmd]

Originally Posted by tomard

Here is illustration from shop manual ... doesn't show anywhere what wire does what ..... I will confirm the connector, but I am pretty sure they are same.

I knew the ~'80 GM models had peculiar parts like Q-jets with TPS but no ECM and non-ECM switched TCC circuits in the early 200-4Rs. But that's pretty interesting in the TH350-C how they made the TCC work based on speed vaccuum and temp with no ECM. I'm laughing here.

The bottom line is that your TCC is going to work off of the same voltage. They used that gov. pressure switch to avoid low speed lockup drivability problems. That could be accomplished in other ways such as a VSS source & a switching setup of some sort. If you're deadset against an ECM at some point I'd consider adding the gov. pressure switch to the 200-4R but I'm not the guy to tell you whether the 200-4R has a tap into that circuit. The rest of the wiring will work fine; short of perhaps a physically different plug and that's easy enough.

You truly learn something new every day.

[GNeric]

That TH350C probably has a blue connector, the BQ should have a black connnector, and the 700 uses a white connector. The black connector has the same pin setup as an IAC socket. The 700 is different and the blue is totally different from those as well. The little "guides" inside where the pins are will show you the differences.

[tomard]

I am taking out the Th350C, hopefully get it done today (Friday) and will post what connector is actually on there.

BowTieOverdrives, says that they have a "External Wiring Kit" that they will sell me for $95 that you can lockup the TCC automatically in 4th, and manually in any gear. But I would lose Cruise Control & I wonder if it is any different than getting the B&M 70244 speedo sensing switch that would lockup at a set MPH, maybe 40-45mph .....

Or, just keep existing setup (possibly need to change harness switch, but don't think so as a vette buddy of mine did the conversion of TH350C on his 81 and it plugged right in - but hasn't been tested yet), and if up shift points are too early or late downshifts, I can just drive in 3rd gear in town, and only use OD when on the road?

Some of you guys are truly amazing on this stuff though - and I wonder that I would have done if it wasn't for the internet and this Buick forum ....... TOO DAMN

[tomard]

Since I have a 4BQ valve body and it IS different from non-GN valve bodies that I have seen so far, in that my vb has TWO pressure switches, is that for 4th gear lockup or something totally different??

Here is picture, if that helps any .....
http://i244.photobucket.com/albums/g...0/100_0931.jpg


BTW - don't laugh too much, that stuff really did work, before I started tinkering

[gsgns4me]

Originally Posted by tomard

Since I have a 4BQ valve body and it IS different from non-GN valve bodies that I have seen so far, in that my vb has TWO pressure switches, is that for 4th gear lockup or something totally different??

Here is picture, if that helps any .....
http://i244.photobucket.com/albums/g...0/100_0931.jpg


BTW - don't laugh too much, that stuff really did work, before I started tinkering

For what it's worth, here are the wiring configurations for all 1987 model 200-4R's. Most other years are similar.

[GNeric]

If you want to save yourself the $95, do like I do when I build one for non computer use. I run a 1 amp fuse from Key On source at the fuse block to "A" pin on connector to the positive side of the solenoid. Run the negative side of the solenoid to the 4th pressure switch and it will lockup automatically in 4th. You can interupt the ground side and add your own switch to ground and make it lock up when you want. Solenoid receives 2nd gear oil and has the capability to lockup at that time. Never had any problems in the last 20 years building them like this and I just don't lockup the stock type converters at WOT with this set up.

[tomard]

Now that is what I am talking about - you guys are great!

I have the lower left vb, with the two pressure switches ..... and planning on using an ACC 2800-3200 Street Bandit TC.

So I guess I will remove the lone wire coming down from my vacuum switch to the Th350C now? I think it must have 12v switched, but could be wrong!
I will send you picture of what that looks like when I get back to the house (& my own PC)

[tomard]

http://i244.photobucket.com/albums/g...TCC80vette.jpg

I have a single wire coming down to 350C (into a dual pronged plug that obviously has to be changed to the 200-r4 4prong plug) ....

Then there are two pressure switches in vb (3rd & 4th gear) on the TCC solenoid on the 200-r4!

The brake switch disengages tcc lockup now, so I am thinking that the wiring harness should be able to be used ...... am I thinking backwards somehow?

[SSedan64]

Originally Posted by tomard

http://i244.photobucket.com/albums/g...TCC80vette.jpg

I have a single wire coming down to 350C (into a dual pronged plug that obviously has to be changed to the 200-r4 4prong plug) ....

Then there are two pressure switches in vb (3rd & 4th gear) on the TCC solenoid on the 200-r4!

The brake switch disengages tcc lockup now, so I am thinking that the wiring harness should be able to be used ...... am I thinking backwards somehow?

Here's a cheap place to get the plugs>
200-4R Switches & solenoids: Bulkpart transmission parts

[YGETV8]

Originally Posted by GNeric

If you want to save yourself the $95, do like I do when I build one for non computer use. I run a 1 amp fuse from Key On source at the fuse block to "A" pin on connector to the positive side of the solenoid. Run the negative side of the solenoid to the 4th pressure switch and it will lockup automatically in 4th. You can interupt the ground side and add your own switch to ground and make it lock up when you want. Solenoid receives 2nd gear oil and has the capability to lockup at that time. Never had any problems in the last 20 years building them like this and I just don't lockup the stock type converters at WOT with this set up.

Okay, just to clarify: I can use the latter of your ideas here to just make a simple toggle on/off lockup switch, correct? What color is the wire for "pin A" (to run a switched 12V source) and and the ground (to run a toggle switch to ground) and you are talking about the plug at the tranny, right?

Thanks! Jay

[SSedan64]

This may or may not help you with your question. Hope it helps.
4th Gear Lockup diagram

[SSedan64]

This site has a diagram with wiring color also. It's kind of hard to read though. Schroll down about 3/4 of the page it shows a TCI* kit wiring.
700R4 Info Page 1