Smallcar shift kit question

[Trevor]

Originally Posted by Budfreak

Well, Like I said, Mine has two terminals on it and they are joined by a resistor. Sucking on it is how I checked the resistance to begin with and like I said, It was reading backwards with the high OHMs with vacuum and the low OHMs without. Is the most sensitive setting all the way in or out?

Crossed purposes again

You have three terminals to identify. I have never sighted the switch which is being used so can not assist with the mechanical aspects. However using simple logic you should be able sort things out with the switch clear of any control wiring.

[Trevor]

Having dug deep in my brain box and recalled from the past, I now realize that once again Harvey is out of line and has put you crook.

The 670 ohm resistor is connected across the normally closed contacts on the pressure switch, which are wired in series with the OEM resistor. In this way, the OEM resistor is always remains in circuit, but with 670 ohms in series when the switch opens/operates.

This arrangement prevents trouble light indication, while the added resistance nullifies the secondary control signal normally present via the OEM resistor. This raises line pressure and creates firmer shifting. ( N.B. At the same time the "A" solenoid valve seat is put under additional stress, as I have many times pointed out.)

This arrangement was finally decided upon, so as to hopefully make connection fool proof. The normally open contact thus not required was to be removed so as to prevent confusion. Hence the currently detailed confusion. confused:

Therefore the two contacts you have, with a resistor soldered between are simply connected in series with the OEM transmission resistor. I.E. you cut the wire to or from the OEM resistor and insert the switch and incorporated auxiliary resistor in the broken circuit, using the two remaining terminals on the switch.

Testing ---- When you operate the switch by sucking on it, the resistance between the two terminals, (nothing else connected), should change from a practical zero to a nominal 670 ohms. If this does not occur reliably, there is a fault.

What a marathon this ****** kit has become !!!!!!!! (Can something/this, be put in the "how too stuff" so that this does not have to be gone through again?)

[Budfreak]

Originally Posted by Trevor

Having dug deep in my brain box and recalled from the past, I now realize that once again Harvey is out of line and has put you crook.

The 670 ohm resistor is connected across the normally closed contacts on the pressure switch, which are wired in series with the OEM resistor. In this way, the OEM resistor is always remains in circuit, but with 670 ohms in series when the switch opens/operates.

This arrangement prevents trouble light indication, while the added resistance nullifies the secondary control signal normally present via the OEM resistor. This raises line pressure and creates firmer shifting. ( N.B. At the same time the "A" solenoid valve seat is put under additional stress, as I have many times pointed out.)

This arrangement was finally decided upon, so as to hopefully make connection fool proof. The normally open contact thus not required was to be removed so as to prevent confusion. Hence the currently detailed confusion. confused:

Therefore the two contacts you have, with a resistor soldered between are simply connected in series with the OEM transmission resistor. I.E. you cut the wire to or from the OEM resistor and insert the switch and incorporated auxiliary resistor in the broken circuit, using the two remaining terminals on the switch.

Testing ---- When you operate the switch by sucking on it, the resistance between the two terminals, (nothing else connected), should change from a practical zero to a nominal 670 ohms. If this does not occur reliably, there is a fault.

What a marathon this ****** kit has become !!!!!!!! (Can something/this, be put in the "how too stuff" so that this does not have to be gone through again?)

OK, Here's the thing. My shift kit has 2 contacts and another one that appears to be broke off at the base. When I test between the 2 contacts that are there(the ones with the resistor soldered between them) I get 670 OHMS with the switch closed(vacuum) and 1 OHM with it open(no vacuum).(which is the opposite of what you are saying)

If I test between the broken off one and the side terminal, I get 1OHM with the switch closed(vacuum) and I get an infinite reading when the switch is open(no vacuum).

If I test between the broken terminal and the terminal directly next to it I get 670 OHMs with the switch closed(vacuum), and an infinite reading when the switch is open(no vacuum).

This is the best I can explain it, So what the hell is going on here??

[Trevor]

Originally Posted by Budfreak

OK, Here's the thing. My shift kit has 2 contacts and another one that appears to be broke off at the base. When I test between the 2 contacts that are there(the ones with the resistor soldered between them) I get 670 OHMS with the switch closed(vacuum) and 1 OHM with it open(no vacuum).(which is the opposite of what you are saying)

If I test between the broken off one and the side terminal, I get 1OHM with the switch closed(vacuum) and I get an infinite reading when the switch is open(no vacuum).

If I test between the broken terminal and the terminal directly next to it I get 670 OHMs with the switch closed(vacuum), and an infinite reading when the switch is open(no vacuum).

This is the best I can explain it, So what the hell is going on here??

Don't panic, you are not the first to become confused in respect of what is involved.

Electrical terminology dictates that a normally open contact keeps a circuit open when the associated device is inert/stationary/inoperative/not energized. Conversely, a normally closed contact provides a closed circuit under the same circumstances.

When the device is operated, or when an electrically operated device is energized, a normally open contact closes and a normally closed contact opens.

Change over contacts incorporate a single moving contact, which provides a common normally open and closed circuit. Consequently the device has three terminals, which is what you are involved with here.

(1) ----- "If I test between the broken off one and the side terminal, I get 1 OHM with the switch closed (vacuum) and I get an infinite reading when the switch is open (no vacuum)."

OK. One ohm we can regard in practice as zero ohms and that with vacuum the circuit is is completed between the moving contact and what is a normally open contact. With no vacuum the circuit is open.

N.B. This contact set is correctly described as normally open.

(2) ---- "If I test between the broken terminal and the terminal directly next to it I get 670 OHMs with the switch closed(vacuum), and an infinite reading when the switch is open(no vacuum)."

????? With vacuum the circuit is opened between the moving contact and what is a normally closed contact resulting in the resistance connected across the contact becoming the only conducting medium, i.e. 670 ohms. With no vacuum the contact is closed and this should result in a near zero ohms reading. However you have stated this as infinite ohms. which relates to an open circuit and it would appear that here lies the confusion. Please check again on this point.

N.B. This contact set is correctly described as normally closed.

I have done my best to make what IS confusing clear. My heed is still opening and closing All the best with yours

[floatingkiwi]

I think your switch is working perfectly. Let me explain (at least this is what I am understanding from the previous explanations).

From Trevors explanation - the resistor should be wired ACROSS the normally closed contacts - then the drawing should look like this: (not sure how to add the picture properly)
39071.jpg
In which case your observations below are perfectly correct:

Originally Posted by Budfreak

OK, Here's the thing. My shift kit has 2 contacts and another one that appears to be broke off at the base. When I test between the 2 contacts that are there(the ones with the resistor soldered between them) I get 670 OHMS with the switch closed(vacuum) and 1 OHM with it open(no vacuum).(which is the opposite of what you are saying)
Actually he is saying exactly that I believe. When you have vacume the switch opens to the left in the diagram and the resistor is connected in series to the top right and bottom terminals. When the switch is closed, to the right, the switch pole bypasses the resistor, hence less than 1 ohm.

If I test between the broken off one and the side terminal, I get 1OHM with the switch closed(vacuum) and I get an infinite reading when the switch is open(no vacuum).
Again correct. With the switch open on vacume (to the left in diagram), you are testing from the top left terminal down to the bottom terminal. When it is closed to the right, no vacume, you have an open circuit from that top left terminal (to any of the others) hence infinite resistance.

If I test between the broken terminal and the terminal directly next to it I get 670 OHMs with the switch closed(vacuum), and an infinite reading when the switch is open(no vacuum).
Which is the top two terminals in the diagram by the sound of things. With the switch open on vacume (to the left in diagram), you are testing from the top left terminal down through the switch "arm" to the bottom terminal then back up through the resistor to the top right terminal which is 670ohm in total. When it is closed to the right, no vacume, you have an open circuit again from that top left terminal.

This is the best I can explain it, So what the hell is going on here??

I think your switch is working and something else is not.

Matt

[Budfreak]

Originally Posted by Trevor

(2) ---- "If I test between the broken terminal and the terminal directly next to it I get 670 OHMs with the switch closed(vacuum), and an infinite reading when the switch is open(no vacuum)."

????? With vacuum the circuit is opened between the moving contact and what is a normally closed contact resulting in the resistance connected across the contact becoming the only conducting medium, i.e. 670 ohms. With no vacuum the contact is closed and this should result in a near zero ohms reading. However you have stated this as infinite ohms. which relates to an open circuit and it would appear that here lies the confusion. Please check again on this point.

Yes, When I test between the broken terminal(NC2) and the terminal next to it(NO3) I get 670 OHMs with vacuum, and a .1 open circuit with no vacuum.

[Trevor]

Originally Posted by Budfreak

Yes, When I test between the broken terminal(NC2) and the terminal next to it(NO3) I get 670 OHMs with vacuum, and a .1 open circuit with no vacuum.

Good one. If you connect things correctly all should work no problem. Please advise results when you have been able to proceed accordingly. as many will be interested.

[Budfreak]

Originally Posted by Trevor

Good one. If you connect things correctly all should work no problem. Please advise results when you have been able to proceed accordingly. as many will be interested.

I'll get to soldering right now and we'll see what happens after a drive. I'll report back shortly.

[Budfreak]

OK, So heres what I did. I couldn't get the solder to work that well, So I melted away at the plastic around the broken terminal and then stripped a piece of wire and very tightly taped it down on top of the terminal. I then hooked up the shift kit by cutting the green/yellow striped wire from the dropping resistor to solenoid A. I attached one end to the wire I taped on to the shift kit, and the other to the side terminal of the shift kit(I believe it was marked"COM"). It seems to be functioning like it should now and I have 3rd gear engine braking, But I also still have a flashing power light. I guess I can live with that though for as long as the shift kit actually works. BTW, I like the way it works so far and I seem to have it set pretty close to where I want it. It shifts very firm when I get on it, But any other time it shifts as normal. So does anybody have any ideas about the blinking power light, or do I just have to live with it?

[oab_au]

Glad you got that sorted out.

As far as the flashing light goes. I think this is caused by the resistor that they have used to increase the dropping resistance. The resistance is too high when the switch opens.

The normal setup has about 12 Ohms for the dropping resistor, 3 Ohm for the A solenoid. This 15 Ohm flows about 933 Mil amps. At closed throttle it is 95% or 827 Mil amps. When the throttle is fully open it is 5% or 43 Mil amps.

When the kit is fitted, and it opens at about 50% throttle, the combined resistance with the 680 Ohm resistor, is about 700 Ohms flowing 20 Mil amps. When the switch opens at about half throttle the current flow drops to 50% of that, or 10 Mil amps, if the pedal is on the floor, it drops to 20 Micro amps.

The TCU is expecting to see about 43 Mil amps, but sees 20 micros instead, decides something is wrong so it posts the code. The fix would be to reduce the additional 680 Ohm resistor to a, 47 Ohms 1/2 watt.

This would see 25 Mil amps at half throttle, and 2.5 Mil amps at full throttle, which should keep the TCU happy.

Harvey.

[Trevor]

Originally Posted by oab_au

Glad you got that sorted out.

As far as the flashing light goes. I think this is caused by the resistor that they have used to increase the dropping resistance. The resistance is too high when the switch opens.

The normal setup has about 12 Ohms for the dropping resistor, 3 Ohm for the A solenoid. This 15 Ohm flows about 933 Mil amps. At closed throttle it is 95% or 827 Mil amps. When the throttle is fully open it is 5% or 43 Mil amps.

When the kit is fitted, and it opens at about 50% throttle, the combined resistance with the 680 Ohm resistor, is about 700 Ohms flowing 20 Mil amps. When the switch opens at about half throttle the current flow drops to 50% of that, or 10 Mil amps, if the pedal is on the floor, it drops to 20 Micro amps.

The TCU is expecting to see about 43 Mil amps, but sees 20 micros instead, decides something is wrong so it posts the code. The fix would be to reduce the additional 680 Ohm resistor to a, 47 Ohms 1/2 watt.

This would see 25 Mil amps at half throttle, and 2.5 Mil amps at full throttle, which should keep the TCU happy.

Harvey.

Harvey, on what basis are you claiming that the modulaed secondary circuit current. is in some strange way linear with throttle position, or in fact is in any way related to total solenoid operating current ? Once again you are confusing this thread with that which is nor correct.

The value of 670 ohms was fixed by Small Car on a trial and error basis and was established at a lower than necessary value. Others it appears have reported no problems when all is connected properly.

[oab_au]

Originally Posted by Trevor

Harvey, on what basis are you claiming that the modulaed secondary circuit current. is in some strange way linear with throttle position, or in fact is in any way related to total solenoid operating current ? Once again you are confusing this thread with that which is nor correct.

The value of 670 ohms was fixed by Small Car on a trial and error basis and was established at a lower than necessary value. Others it appears have reported no problems when all is connected properly.

I don't think I am confused, in what I have said. Though I don't understand what you are getting at. Can you explain what you mean by

" on what basis are you claiming that the modulaed secondary circuit current. is in some strange way linear with throttle position, or in fact is in any way related to total solenoid operating current ? "

Harvey.

[Trevor]

Originally Posted by oab_au

Glad you got that sorted out.

As far as the flashing light goes. I think this is caused by the resistor that they have used to increase the dropping resistance. The resistance is too high when the switch opens.

The normal setup has about 12 Ohms for the dropping resistor, 3 Ohm for the A solenoid. This 15 Ohm flows about 933 Mil amps. At closed throttle it is 95% or 827 Mil amps. When the throttle is fully open it is 5% or 43 Mil amps.

When the kit is fitted, and it opens at about 50% throttle, the combined resistance with the 680 Ohm resistor, is about 700 Ohms flowing 20 Mil amps. When the switch opens at about half throttle the current flow drops to 50% of that, or 10 Mil amps, if the pedal is on the floor, it drops to 20 Micro amps.

The TCU is expecting to see about 43 Mil amps, but sees 20 micros instead, decides something is wrong so it posts the code. The fix would be to reduce the additional 680 Ohm resistor to a, 47 Ohms 1/2 watt.

This would see 25 Mil amps at half throttle, and 2.5 Mil amps at full throttle, which should keep the TCU happy.

Harvey.

It would appear that you have made a connection to the terminal normally cut off by Small Car to prevent confusion, i.e. what you have referred to as a broken terminal. **This should be the normally open contact and is not used.

That marked COM is the moving contact of the change over set and the other one is the normally closed which IS used. You should have the normally closed and the COM in series with the circuit and the 670 ohms wired across these contacts. The kit should have been supplied set up accordingly.

** Has Small Car by any chance cut off the wrong terminal and or wrongly attached the 670 ohms ? By logically using the details I have posted you should be able to sort this out.

[Budfreak]

Read over my test results again carefully Trevor in post #33 and see what happens when I hook it up the way it is supposedly supposed to go. I'm thinking I may have an old model that was retrofitted with the resistor.

[Trevor]

Originally Posted by Budfreak

Read over my test results again carefully Trevor in post #33 and see what happens when I hook it up the way it is supposedly supposed to go. I'm thinking I may have an old model that was retrofitted with the resistor.

I have explained everything in great detail and as simply as possible, after expending a great deal of time. It is over to you to go over everything logically and find the answer. Start from scratch and check that the actual bare unit is connected and operating properly.

I have no more time this evening as I have to prepare for a trip in the morning to collect a new toy, a nice Mazda Mx5. Not having an open sports car has not made ma a happy chappy .