700r4 lock up control ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

13lazer · 03-05-2006, 03:08 AM

my b&m lock up control w/ mechanical speed sensor has been nothing but a headache. the wire connections are pitiful, they hadn't been soldered. they backed out of the plugs almost immediately after i opened the box before my tranny was even installed. i have been trying to hardwire directly to the pins in the dash mounted module with no success. i have ruined the controller and im glad because it sucks.
My question is if i drive without lock up engaged will my tranny be damaged. it is running well below 150 degrees F. the tranny is from a 1989 truck. im trying to decide on my best option to control my torque converter. in the meantime i don't have any other transportation. will i burn up my 4th gear if i get on the freeway? i might not solve this problem for a week or two. should i avoid driving until i get this right, or am i just losing some fuel economy?
who's system works best? raptor, tci, painless, bto,..
any suggestions?
thanx

**pjmoreland** · 03-05-2006, 03:20 AM

You could temporarily just wire the lockup circuit straight to 12 volts (IGN UNFUSED). For driving around town, just leave your transmission in 3rd gear, and when you get out on the highway shift to OD, and the TCC will lock up whenever you are in OD.

I used a brake light switch out of a late '70s van that has two sets of contacts in it. One set is for the brake lights. I used the other set to provide 12 volts to the TCC circuit. That way when I hit the brakes, the TCC releases. I also installed a manifold vacuum switch from a mid-80s truck for releasing the TCC when I press the accelerator down fairly far.

13lazer · 03-05-2006, 04:41 AM

there are 3 wires red, yellow, and ground. red to ign unfused, yellow on a toggle switch i can engage at will. right now i have a relay that powers up the yellow wire on the brake signal? what causes the t.c. to lock up, 12v. or open circuit? i think i can do this. i'll look in my book. i thought it was more complicated than a 12 volt signal.

Blazerb61 · 03-05-2006, 08:58 AM

Most electronic transmissions are controlled on the ground side The tcc locks up when it is grounded

**pjmoreland** · 03-05-2006, 06:16 PM

I have a 1988 700R4 in my truck. It requires 12 volts to lock up. The ground is provided inside the transmission to complete the circuit.

**pjmoreland** · 03-05-2006, 06:20 PM

This link has good information:

http://www.highperformancecars.com/crosley/lockup1.htm

I had to install a loop on the electrical connector as shown on page 3.

13lazer · 03-05-2006, 06:51 PM

thats awesome, i was looking for something like that. im sure i can do it without spending the $150 on a new b$m module
thanks for the link
13lazer

03-05-2006, 03:08 AM	#1
13lazer 13lazers' blazers Join Date: Jul 2005 Location: San Pedro, CA Posts: 152	700r4 lock up control ? my b&m lock up control w/ mechanical speed sensor has been nothing but a headache. the wire connections are pitiful, they hadn't been soldered. they backed out of the plugs almost immediately after i opened the box before my tranny was even installed. i have been trying to hardwire directly to the pins in the dash mounted module with no success. i have ruined the controller and im glad because it sucks. My question is if i drive without lock up engaged will my tranny be damaged. it is running well below 150 degrees F. the tranny is from a 1989 truck. im trying to decide on my best option to control my torque converter. in the meantime i don't have any other transportation. will i burn up my 4th gear if i get on the freeway? i might not solve this problem for a week or two. should i avoid driving until i get this right, or am i just losing some fuel economy? who's system works best? raptor, tci, painless, bto,.. any suggestions? thanx

03-05-2006, 03:20 AM	#2
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,315	Re: 700r4 lock up control ? You could temporarily just wire the lockup circuit straight to 12 volts (IGN UNFUSED). For driving around town, just leave your transmission in 3rd gear, and when you get out on the highway shift to OD, and the TCC will lock up whenever you are in OD. I used a brake light switch out of a late '70s van that has two sets of contacts in it. One set is for the brake lights. I used the other set to provide 12 volts to the TCC circuit. That way when I hit the brakes, the TCC releases. I also installed a manifold vacuum switch from a mid-80s truck for releasing the TCC when I press the accelerator down fairly far.

03-05-2006, 04:41 AM	#3
13lazer 13lazers' blazers Join Date: Jul 2005 Location: San Pedro, CA Posts: 152	Re: 700r4 lock up control ? there are 3 wires red, yellow, and ground. red to ign unfused, yellow on a toggle switch i can engage at will. right now i have a relay that powers up the yellow wire on the brake signal? what causes the t.c. to lock up, 12v. or open circuit? i think i can do this. i'll look in my book. i thought it was more complicated than a 12 volt signal.

03-05-2006, 08:58 AM	#4
Blazerb61 Registered User Join Date: Aug 2005 Location: Davenport Iowa Posts: 115	Re: 700r4 lock up control ? Most electronic transmissions are controlled on the ground side The tcc locks up when it is grounded

03-05-2006, 06:16 PM	#5
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,315	Re: 700r4 lock up control ? I have a 1988 700R4 in my truck. It requires 12 volts to lock up. The ground is provided inside the transmission to complete the circuit.

03-05-2006, 06:20 PM	#6
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,315	Re: 700r4 lock up control ? This link has good information: http://www.highperformancecars.com/crosley/lockup1.htm I had to install a loop on the electrical connector as shown on page 3.

03-05-2006, 06:51 PM	#7
13lazer 13lazers' blazers Join Date: Jul 2005 Location: San Pedro, CA Posts: 152	Re: 700r4 lock up control ? thats awesome, i was looking for something like that. im sure i can do it without spending the $150 on a new b$m module thanks for the link 13lazer



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