OK, I finally got the front brakes finished and can't start the tank switch yet, so I thought it would be a good time to check the solenoid resistance.



Would someone give me a diagnosis? The readings were about 1ohm lower on a different meter. Looks as thought I might have trouble on solenoid 2.

yup, solenoid 2 looks out of range. of course i would triple check again.

And the next step would be..................?

If the trans changes ok, leave it alone

If it does not, replace the solenoid, its easy enough to do, just drop pan

if Solenoid No2 fails, you will have no 2nd or 3rd (I think, check the FSM)

I had to change mine out

imo 34 Ohms will probably still work

Your choice...I advise check resistance of solenoid itself if pan is down, as it can be the wiring

The trans won't shift on it's own. The problem occurred while it was unused (sitting for about 4 years) while I didn't have the funds to get it running again. I had to move it from time to time and one time it stopped shifting. Nothing had been changed on it. I finally got the cooling problem fixed and it runs like a top, just won't shift.

One way to rule out mechanical or electrical is to disconnect TCM under glove box side dash. See if it shifts all gears manually. There is fuse close to the TCM to check also. TPS in renix years also sends a signal for transmission. TPS can be operating throttle fine but shifting side can be goofed. All of my bad TPS's had shifting problems first, as in not upshift out of first til 3500 rpms. Check resistance at connector by trans dipstick also.

You search for "no shift" here but take note the non renix years are a bit different electrically. Not at my computer with saved links or I would send a few .

When I did the resistance tcu was unplugged. There's no difference when the tcu is plugged in and it has power at the fuse but there is a fuseable link (I think) that has 12v on one side.


I guess I'll do TPS diags tomorrow. I need to spring for a better meter, I have two, the one I got with my electronics degree, and one I got free from HF. Neither are correct but in the ball park. I will get an analog meter if I can find one. I am learning that a renix requires accuracy and making reliable solder joints. Seventy two and still in school.

If it works when stick shifted, but not "on its own" as an auto, that will be the TCM or wiring

reverse is mechanically engaged. If you have no reverse, something else is the problem

That's not a fusible link, it's a resistor that's part of the wiring that watches for brake pedal application (so the TCU knows to unlock the torque converter)

There are two 8-pin connectors under the hood where the harnesses going to the drivers side of the trans and the passenger side for the neutral safety switch connect. Try checking the resistance there, and cleaning those connectors. If the wiring looks good and you're still seeing high resistance, then it's time to replace the solenoid. The set of three solenoids is under $70 on amazon. Replacing them isn't hard. Just don't overtighten the screws in the oilpan you risk ripping out the aluminum threads. It's only 7 ft-lbs, which isn't much more than firmly snug.

Cruiser54 told me not to do the oil pan, I told him I was going to drain the transmission and replace the filter and he didn't think I needed to do that. I was hoping he might see this thread. I'm 72 and have worked on all my vehicles. I can't put in the hours on concrete that I used to (old injury) but what can do is research when I'm not in the garage. Thanks to all for the feedback.
Charlie

All gears are fine. There's a solid shift from 1st to 2nd, not so much into 3rd. If I follow what I'm being told I'll eventually get it straightened out. The old girl (we're not supposed to do that) still runs like a dream. There's a lot of miles left in it.

Cruiser's right. The filter is just a fine metal mesh screen that doesn't need replaced. If I have the pan off for another reason, I just check it for debris and then rinse it out with some solvent instead of wasting money buying a new filter. I wouldn't drop the pan just to replace the filter.

Check the connector from the harness down to the transmission for any corrosion on it's pins before diving into the trans. I'm assuming it's the same on yours as it is on the later ones. If it looks clean, check your resistances from there. if #2 is still high, then it's probably the solenoid.

Thats where I do all my checks from, and have a hat pin with wire permanently plugged into the socket, my TC solenoid seems to not work 100% of the time

resistance is 125 Ohms, ( but measured 14 at the solenoid), I suspect its in the harness between that plug and solenoid, yet to be confirmed

the pan will need to be dropped to investigate this further, and will attend the 3 x stripped setscrews while I am at it

Done. The results are close to the originals. Suggestions?