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TH350 tranny electrical ? Need help!

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BlitzK5

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Before I started my Blazer overhaul I noticed the electrical connections on my TH350 (one on each side) where conected to the transmission but not conneceted to anything else on the vehicle. The connections are also melted on the other ends not connected to the tranny so I would'nt know were to connect them anyway to the vehicle. Now that I am slowly hooking everything back up. Do I need to worry about these connections from the tranny to the vehicle. Obviously they were not hooked up before to anypart of the vehicle other then on the tranny and the tranny worked, so should I be worried about it now. I guess I could go to a tranny shop and order up a new wire harness but I would'nt know where to hook them up to. Does anyone have any idea as to if I need them or not and if so, were would they go and what are these connections used for?

Thanks
 
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Some TH350's came with a lockup torque converter and I bet the wiring has to do with that.

Not sure though....


Yep, I Was right...

The HydraMatic 350 transmission was prevalent in nearly all GM, rear-wheel-drive cars and trucks through 1981. It was typically paired with Small Block V6 & V8 engines. It was produced as the TH350-C through 1984. This later version had an electronic lock-up converter to increase fuel-efficiency at cruising speeds.
Click to expand...
 
So in that case by having nothing electricly connected to the tranny it should be fine for driving then. I was affraid of damaging something but I guess the electrical connections were just for the lock up thing only. Correct?
 
Driving a tranny without the lock-up convertor working will kill the tranny. There are kits to eliminate the lock-up feature but it involves changing the convertor for a non-lock up one and i think changing the input shaft at the same time.
 
Isn't there also a connector for the back up lights on the tranny? I haven't dealt with the 350's much, but I know that my 700r4 has the connector for the backup lights.
 
4X4HIGH said:
Driving a tranny without the lock-up convertor working will kill the tranny. There are kits to eliminate the lock-up feature but it involves changing the convertor for a non-lock up one and i think changing the input shaft at the same time.
Click to expand...

Well maybe the lockup convertor has been removed from its prevous owner since the connections were not hooked up to anything. Is there any way to double check?
 
I wouldn't be surprised if no lockup on a TH350C wouldn't hurt anything. That was added to the transmission as an afterthought, while the TH700, 200, etc were all designed with the TCC in mind.
 
dyeager535 said:
I wouldn't be surprised if no lockup on a TH350C wouldn't hurt anything. That was added to the transmission as an afterthought, while the TH700, 200, etc were all designed with the TCC in mind.
Click to expand...

I doubt that the TH350C was an after thought since it has a different case and also uses a lock-up convertor just like a 700R4 does. :confused:
 
TH350 has been around since when? 1968? TCC was installed in a TH350 starting in? 1980? It was an afterthought. The same ATSG rebuild manual for a TH350 is used for a TH350C. (at least the one I have is)

I'd be surprised if there were many different parts in the TH350C other than the converter, the input shaft, case (to accomodate the TCC solenoid and/or wiring) and whatever the TCC got in the way of.

TH350 was designed originally with enough fluid capacity, cooling, and the fluid paths to not overheat with a slipping converter, adding TCC to that transmission shouldn't reduce the ability of it to cope with heat.

In any case, if you can run lockup, run it. If you can't, then I wouldn't worry about it, as long as the trans is cooled well.

All I'm saying is, any GM trans first used after 1981 was designed with no converter slip as a factor in how it cooled. That makes sense as to why the 700 and the like are not recommended to be run without functional TCC. Any prior to that, had to cope with a slipping converter at all times, and were designed from the ground up that way.
 
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