miata SGT signal

[POS Racing]

So the POSIV isn't wanting to start, so I hooked up (GND) and (TEN) and the dash light flashes 3 times. Miata.net is showing this is a SGT signal error for a '94 Miata. (LINK)

So what do I do now??

[onething]

I would first figure out what that means, and then call the PO for a refund

[POS Racing]

I would first figure out what that means, and then call the PO for a refund

I called the number it says it has been disconnected and no further information is available....... Is that a bad sign??

Any way to test the CAS off the car??

[wrx74]

Linke

[POS Racing]

Once again wrx74 to the rescue!

If you don't know how to use a voltmeter, you should not be doing this.

With the connector oriented like this (tab up), the normal measurement is 0 volts, +12 volts, +5 volts, +5 volts. As shown, the black wire in the harness with be at the left


Also check the first pin (black wire) for continuity to ground

If the voltages and ground connection check out, the wire harness to the computer is good.

So I was able to determine I have a good ground 12V and two 5V on the harness as per the link.

But Next step is to bench test the CAS, but I can't figure out a decent way top generate the 5V they mention in the article..... Not sure how to proceed.

Electrical Test - per shop manual
You have to remove the CAS and attach power to it.

The factory shop manual shows the above method for testing the CAS. Hook up power and ground. Then you need a load resistor and a 5 volt supply. With a volt meter hooked up to the resistor, you will read either 0 or +5 volts, depending on the position of the CAS rotor.

The SGC pin should switch between +5 and 0 volts twice per revolution.
The SGT pin should switch between +5 and 0 volts four times per revolution.

[wrx74]

I was just wondering if you could try the CAS off one of your SPARE CARS?

[POS Racing]

I was just wondering if you could try the CAS off one of your SPARE CARS?

Nope no CAS on the other two.

[goofygrin]

How many amps you need? Just about every modern cell charger puts out 5v at some lowish amp rating (most are < 1a).

Or you can use a PC power supply if you need more. If all you have is an ATX power supply you can hook two pins together to make it fire up like the old AT power supply (google it).

The benefit of using the PC power supply is that it will have 12v for you as well.

[TurboDuane]

I have a spare CAS if you want to borrow it. I've had it since my Link computer was messing up a year back. It's good and works fine. It came off my '97.

[creek]

I would think a cheapo 6 volt lantern battery would be plenty for a short test.

[wrx74]

Maybe?? Linke

[Flyin96M]

I've also got an extra CAS off a 94 if you need to borrow one. I can't remember if it was different from OBDI to OBDII, but the offer is on the table if you need it.