wiring for OD

[Anders]

Ok,

 

Adjusted the linkage, still no OD, now will occasionally, and just occasionally free wheel when I am out of the gas.

 

 

What is the wiring points for OD?

 

what to look for?

 

Thanks

 

Tried grounding the temp sensor, pulling OD relay, no help...checked OD cancel switch...no click is heard when I am testing downshift solenoid, but it does downshift...could this be it?

 

What other electric issues can there be with it?

 

Thanks

[1st_gen_eclipse_89]

did you try pulling the BACK fuse in your fuse box?? its the last fuse on the bottom right side.

[Anders]

yup, and thats not it....

 

Thanks though...woudl the kickdown switch have anything to do with it?

 

C

[1st_gen_eclipse_89]

yeah, if you say the tranny is "floating" when you get of the gas, my old starion did that too. my kick down switch might have been the problem, but i yanked out the tranny and got i 5sp b4 i figured out wht it was doin that.

[TylerQuest]

mine is doing the same thing....I have been chasing it for a while now. I wonder, if the kickdown switch is bad, and keeping the car out of OD, would simply unplugging the switch fix the problem?

[Anders]

Anyone know the answer to that?

[1st_gen_eclipse_89]

if you unplug the kick down switch, and pull the BACK fuse out, its all the way on the bottom right of the fuse box, your overdrive should engage. if it doesnt you either have a bad or sticking O.D. solenoid or you might have some serious tranny problems. what i usually do is pull the O.D. fuse while im driving and it usually drops into overdrive. i tried doing the same thing with the rear end on jack stands and it didnt work. i think the tranny has to be under a load for it to work. you should try it.

[TylerQuest]

The Back fuse contains the circuit for the OD switch on the shifter. Pulling it out will tell you if you have a bad switch at the button.....still not real sure about the kickdown switch.

Can someone with an auto test this theory? Unplug your kickdown switch and see if the car shifts into OD as normal? Somebody try it out and post the answer here please!

[1st_gen_eclipse_89]

The Back fuse contains the circuit for the OD switch on the shifter. Pulling it out will tell you if you have a bad switch at the button.....still not real sure about the kickdown switch.

Can someone with an auto test this theory? Unplug your kickdown switch and see if the car shifts into OD as normal? Somebody try it out and post the answer here please!

 

now when i pulled my BACK fuse, i can hear the relay and the solenoid clicking. i dont hear that same clicking when i cycle my OD switch, so im thinking that fuse cuts power to everything, not just the switch. as for the kick down plug test, im in the middle of changing a TB gasket, so i'll try if 4 u after that and see what happens

[1st_gen_eclipse_89]

The Back fuse contains the circuit for the OD switch on the shifter. Pulling it out will tell you if you have a bad switch at the button.....still not real sure about the kickdown switch.

Can someone with an auto test this theory? Unplug your kickdown switch and see if the car shifts into OD as normal? Somebody try it out and post the answer here please!

 

ok, got my starquest back together. i pulled the kick down plug like you asked and it still goes into overdrive. i even cycled the O.D. button a couple of times. overdrive engaged everytime. i doubt thats your problem. if you turn your ignition on, but not start the car, do you hear a clicking noise from under the dash and under your car when you pull the BACK fuse??? if not, its like i said before, you might have a sticking O.D. solenoid. it would cause the problems you are talking about. either that or a serious tranny problem. did you try unplugging the solenoid on the tranny. do this with the ignition on and you should hear a loud click when you unplug it. i mean its pretty load when you are under the car, so you cant miss it. if not, theres you problem.

[rabsol1]

Hey all,

 

Been working with the no OD shift for a little while now myself on a Blue 88 TSi. Replaced OD relay, checked for power where needed, checked kickdown switch, replaced inst. cluster indicator bulb, tried the plug/unplug test on the solenoid, even tested solenoid as per factory shop manual (seems to click everytime it gets power). No luck, an occasional elusive OD shift as normal, would stay engaged for about 15-45 seconds, then drop back out of OD. And that was seldom to be had.

 

Sooo, after reading the posts in this thread (thanks to all!) I just tried pulling the BACK fuse while at normal highway cruise. And voila! OD engaged and was just as it should be.

 

Now, if I may ask....since this fuse-pull test led to the OD shift, what is the solution? Trans is great, never missed or over slips a shift ever, fluid is clean and any burn is non-existent. And if it is solenoid or whatever else, does anyone have a part ref. number for it (I failed to find one in Part # Database).

 

I just had a 4-speed OD trans built over the winter months for an 92 Mazda B2200 that was pretty well smoked. Since I had some years in dealer shops under my belt, the guys that do my trans work tend to work with me a bit more on what to expect, etc. And the fact that they have over 40 years experience helps LOTS too! I haven't went to see them about the OD yet, they live about 50 miles away or so.

 

To sum this up, the guys building the trans told me the auto trans in the StarQuest is a JATCO made unit, and is used in quite a few other vehicles. Like the Mazda pickup I have, some Nissans, and several other makes/cars I can't remeber right now. About the only differences are the obvious ends of the trans, bell housing, tailshaft AND housing, etc. Easy to identify as well....since the JATCO unit was originally designed ar a 3-speed automatic, there is a cast-iron section between the trans main body & bell housing (very easy to identify)...it is the Overdrive unit itself! Which does lend itself to reason why lots have fluid leaks near the front of the trans. The bolts that retain the bell housing ALSO retain the overdrive unit, so they are quite long, similar to head bolts. As age, time & torque take their toll, the length of the bolts may eventually allow some twist on some hard shifts, which twists the bellhousing/OD unit/trans body ever so slightly. With repeated motions, this causes the gaskets between them to kinda mash out/away from their sealing surfaces, which in turn can create a leak. Just a little FYI to share, all has helped me out well so far here....just hoping to return the favor. :wink:

 

And, trust me...I like the Jatco unit...no bad-mouthing them here.

[Tim_C.]

Sometimes shifting into OD, and then not holding it very long unless you finess the gas pedal:

 

This problem on my '85 auto was entirely the vacuum system. The engine was borderline too low on compression. Changed the head, and it fixed it for the most part, but would still do it. Finally needed to rebuild the engine for other reasons, and that fixed it entirely. It finally got a good vacuum signal and the problem went away. I didn't even pull the trans when rebuilding the engine. I unplugged the same vacuum line, and plugged it back in on the new engine, that's all.

I'd check that line for leaks, or make sure you are getting enough vacuum.

[Shelby]

ok seems every one is missing an important fact,,the electrical controls work to DISABLE the OD not enable it , if all wires are unplug'd the trans defaults to OD , keep this in mind while trouble shooting the auto OD circurt

[rabsol1]

Exactly my point Shelby...so if the removing of the BACK fuse takes the power off the circuit...and allows the OD shift to occur (essentially disabling the solenoid)...then what is at fault to not allow the shift to occur with power ON the circuit? Sticky/faulty solenoid? :?

 

And yes....vacuum had been another area I checked one end to another, good point there. I had already ran an external test vacuum gauge on the port to the trans, and had checked all connections at engine & trans, even replaced the rubber line at the engine. ;-)

 

Ah, when many minds come together, things can be figured out in short order.

[Shelby]

the shift modulator on a turbo trany works some what like a vacuum advance unit,,it works the same way in vacuum or boost to control shifting points ,so if a non turbo modualtor was install'd it would not work right as they are made to work with vacuum only

[1st_gen_eclipse_89]

so if the removing of the BACK fuse takes the power off the circuit...and allows the OD shift to occur (essentially disabling the solenoid)...then what is at fault to not allow the shift to occur with power ON the circuit? Sticky/faulty solenoid? :?

 

 

O.K. there are six things at play here. you have...

1. the O.D. button on the shifter,

2. the O.D. relay under the dash,

3. the O.D. soleniod in the tranny,

4. the BACK fuse that diables the whole system,

5. the kickdown switch, and

6. the temp sensor on the engine block.

 

now we have pretty much gone over 1 - 5, but have you checked your temp senor? this sensor keeps the overdrive from engaging until the engine is up to normal operating temperature. it shares the same sensor as yout tepm gauge so it looks like a "T" plug. if you unplug it your temp gauge will bottom out so you know you got the right one. if you turn the plug around and plug in just the prong for your temp gauge and not the O.D. temp side, your gauge will come back on. now just ground the other side of the plug and this will bypass the sensor in case its bad. this is not really a permanent fix. you dont want your overdrive engaging til you are warmed up. bad for the tranny, but it will tell you if the O.D. side of the sensor is bad. you could, if you remember to, just manually turn the O.D. off using the switch on the shifter til the temp goes up. one side of the sending unit has varied resistance for the temp gauge, and the other side just grounds itself at a certain temp. try it.

[rabsol1]

try it.

 

Well....I did. :shock:

 

And might I say, good show!!! Absolutely accurate, and worked like a charm! Again, the board pulls through with yet another sucessful diagnosis. I followed steps exactly as stated, and all that 1st_gen said proved true. Another note I'll file back for use at a later date.

 

I guess that is what I get for spending the majority of my mechanical career in Ford shops, Mitsu is seeming to be quite different...at least electrically. :?

 

Thanks 1st_gen & all else! :wink:

 

Now, time to go do a tune-up on a '49 Ford F-1 pickup (flathead V8 )... Oh, and order a new temp sensor...

[Tim_C.]

Good to hear yours got fixed rabsol1! Now, please step away from those Fords! Just kiddin', but I do prefer GM for domestic cars. Chevy in particular is much easier to work on, runs forever, and less money and effort required to make them go fast!

 

I will move this to the FAQ board, and change the name to "Overdrive 101"