Can you run a 700r4 WITHOUT electrical connection?

[Galane]

Technically, the trans won’t care. It’s worth a little in both fuel economy and cruise rpm to get it working.

Go to your nearest transmission shop, get a TH400 kickdown solenoid case connector and o-ring.

th400 case connector - Google Shopping

www.google.com

You can find the MUCH cheaper, any transmission shop can order the part.

The case connector will fit perfectly where the original 4 wire connector went in the 700. Then you can use common 1/4 female quick disconnects for connections on both side of the connector.

Next, you need a normally open 4th gear pressure switch. Your transmission might already have the proper switch, it grounds thru the switch body when pressurized. If your trans doesn’t have the right one, lots of transmissions use a switch like that, once again your nearest transmission shop will most likely have what you need.

Remove all the old wiring, leaving as much of the TCC solenoid wire length as possible. Connect the red wire to the case connector. Connect the black to the 4th gear pressure switch. Reinstall the pan.

Now, you need a way to control the solenoid. My favorite low buck way is a headlight dimmer switch, especially if the vehicle has the dimmer on the column. Connect the switch in line to the case connector. With the switch turned on, the solenoid will engage as soon as the trans shifts to 4th gear.

You also need a switch on the brake pedal to cut power to the TCC solenoid so the clutch will release when stopping. Otherwise it's just like trying to stop with a manual transmission without pushing the clutch pedal.

1980's GM transverse front drives had a problem with fine debris getting into the TCC valve, causing it to stick closed. Never was a recall on that though I bet that was responsible for a lot of people getting rear-ended. I and family members owned several 80's GM front drives and 100% of them I had to replace that valve. I also replaced it on cars for a lot of other people. The replacement valves have a fine screen on the inlet.

 

[Ricko1966]

@Galane using the 4th gear pressure switch as his lockup he won't need the brake switch,he won't be stopping in 4th gear.

 

[codfish]

Thanks for the info guys.

I’ve got the plug ordered for the lockup connector on the trans. I definitely plan on getting the lockup functioning again. Not necessarily with the brake switch and what not, but a switch and relay for sure. Been watching a few videos about the different ways to get it done.

Codfish

 

[codfish]

I guess I should also mention that the truck won’t see a ton of driving where overdrive will be needed or used, but when it does see some hiway miles it’ll be a nice option for sure.

 

[Ricko1966]

Post number 3 or post 22 either will work great and super easy. If you watch too many videos I'm afraid you'll just get confused,not insulting your intelligence,but I question the intelligence of some youtubers.

 

[codfish]

Thanks Ricko

Just getting back home from my 2 week rotation wwwwaaaayyyyy up north finally.

Got the trans and transfer case back in. Linkages and some smaller items to take care of before it’s all “done”.

Took the pan and filter off to check out the wiring situation. It’s a little different from others I’ve seen pics of. What is the thing in the middle of the wiring harness that all of the wires go through? It has 2 connections, with 2 wires going to each spade. I’ve seen it referred to as an overheat switch?? Is this correct? Any harm in leaving it hooked up, or should I ditch it?

 

[Matt69olds]

That’s a thermal switch. It’s designed to automatically lock the converter if the trans overheats. Not all 700 use one.

 

[hogdaddy]

delete

 

[codfish]

That’s a thermal switch. It’s designed to automatically lock the converter if the trans overheats. Not all 700 use one.

Alright

I guess I’ll delete that when I wire up my lockup circuit.