Hello All,
On my 82 Blazer the coverter locks up sometimes and sometimes it doesnt. I set the brake pedal switch out some to insure it was closing and that did not help. Are there any other "switches" I need to check? If not what could be the problem? When it works it works fine, just like it should

Thanks much,
Art

What trany do you have 700 or 350? With it being an 82 I doubt that it has a TPS on a 700. They didn't come in till way later. I'm pretty sure thats a mechanical setup for lock up. If it's a 700 try resetting the TV cable.

mine did the same sort of thing and never quite figured it out. had constant power from IP to lockup plug. brake cut out worked fine too. sometimes i found fluid level was down a hair and worked better when topped. figured it was internal or a grounding issue.

The '82 6.2 has a mechanical throttle position switch (TPS) on the injector plump (IP). It shuts off power to the torque converter clutch (tcc) at slow speeds and at wide open throttle (WOT). It's a mechanical switch and at 25 years old, sometimes they don't make good connections. On my '82, just the low speed cutout works. Right now, I have it wired to get lockup shifting into 2nd, 3rd, and 4th. I am going to put a toggle switch on so I can leave the transmission (700R4) in no lockup, 4th lockup only, or lockup in 2nd,3rd, and 4th. NOT all valve bodies can be made to lock up in 2nd and possibly 3rd.

The TPS can be purchased at Autozone, and probably other parts stores for $40- $50 as I recall.

Other possible problems are the valve body switches - 4th clutch, 4-3 momentary, or the TCC solenoid. All these switches are relatively easy to replace although you might have to remove your transmission pan to get to some of them.

If you want to pursue the repair, let me know what the model number or the transission is. It is stamped on the lower right rear side of the tranny.

Ok so I was wrong, they did have TPS back in 82. When did they start using them. I know the early ones were no more than an on off switch until later units that were proportionate. What were the cut off years?

Bigboytoys

Your right. The '82 diesels with the 700R4 had the throttle position switch which was a simple on/off device. My '86 GM manual shows them still using the switch. My '91 GM manual shows them using a throttle position sensor. I suspect that around '87 or '88 they changed to a sensor as GM did a lot of changes and upgrades during that period.

TPS as used by GM is a misnomer as they refer to it as both a switch and a sensor.