Peer81
Well-known member
Hello everbody,
To tell the short version, I have a '81 and put in a 700R4 from a '90 Corvette. I'm working on the lockup wiring so the lockup can be controlled by the '81 ECM. I wanted the lockup to kickin at 3rd and 4th.
The '81 ECM gives the following readings on the lockup wiring.
Wire A has a continues 12v.
Wire B gives 12v under 25mph and when braking.
Wire C is for the high gear don't know.
I ordered a vacuum switch to lockup at high intake vacuum.
Ordered a 3th gear switch 2 prong, normally open.
4th gear switch 1 prong, normally open.
4-3 downshift switch 2 prong, normally closed.
solenoid switch 1 prong, normally open.
The idea was to connect wire A to the 4-3 pulse switch, then the solenoid and returning in wire B the 3rd gear switch. Wire C would have the 4th gear switch (as original for this transmission).
Yesterday I dropped the pan and today I wanted to put in the extra switches. But under the trans I found out there isn't any thread left or stops (with thread behind it) left to remove in this valvebody.
You can see on the right the place where I removed the 4th gear switch (above the connector). I had the idea this would be an easy switch of switches but didn't expect this. Am I overseeing something or is there just no easy way to install the switches? As I look at it now my entire lockup wiring is down the drain...
The problem I have now is that the transmission will lockup the second we go over 25mph so I need a switch that is only closed it 3rd and/or 4th gear. As I see it I can switch the single prong 4th gear switch for one with 2 prongs, but I don't find it on the net (normally open). Does anybody have an idea were I can find them? Or as I already have a 2 prong 3rd gear switch (normally open) can I also use that one and place it in the 4th gear switch opening?
Btw. I already have a aftermarket lockup kit but don't want to cut wires when my ECM can do the same and I don't want to use a manual switch to control the lockup.
Greetings Peter
To tell the short version, I have a '81 and put in a 700R4 from a '90 Corvette. I'm working on the lockup wiring so the lockup can be controlled by the '81 ECM. I wanted the lockup to kickin at 3rd and 4th.
The '81 ECM gives the following readings on the lockup wiring.
Wire A has a continues 12v.
Wire B gives 12v under 25mph and when braking.
Wire C is for the high gear don't know.
I ordered a vacuum switch to lockup at high intake vacuum.
Ordered a 3th gear switch 2 prong, normally open.
4th gear switch 1 prong, normally open.
4-3 downshift switch 2 prong, normally closed.
solenoid switch 1 prong, normally open.
The idea was to connect wire A to the 4-3 pulse switch, then the solenoid and returning in wire B the 3rd gear switch. Wire C would have the 4th gear switch (as original for this transmission).
Yesterday I dropped the pan and today I wanted to put in the extra switches. But under the trans I found out there isn't any thread left or stops (with thread behind it) left to remove in this valvebody.

You can see on the right the place where I removed the 4th gear switch (above the connector). I had the idea this would be an easy switch of switches but didn't expect this. Am I overseeing something or is there just no easy way to install the switches? As I look at it now my entire lockup wiring is down the drain...
The problem I have now is that the transmission will lockup the second we go over 25mph so I need a switch that is only closed it 3rd and/or 4th gear. As I see it I can switch the single prong 4th gear switch for one with 2 prongs, but I don't find it on the net (normally open). Does anybody have an idea were I can find them? Or as I already have a 2 prong 3rd gear switch (normally open) can I also use that one and place it in the 4th gear switch opening?

Btw. I already have a aftermarket lockup kit but don't want to cut wires when my ECM can do the same and I don't want to use a manual switch to control the lockup.

Greetings Peter