Question about Extended Idle

[Joukel]

Hello there,

Recently I wired an extended idle switch on my '97 4.0 automatic, for keeping the engine cooler and voltage higher when I'm winching.
I connected the grey wire A12 from the PCM to the ground but nothing happens.. I checked for continuity and it should all be good.

The car is in park/neutral, which is necessary for it to work. I was thinking maybe it doesn't get a good signal from the Neutral Safety Switch, but then again it wouldnt start at all if I'm right? Because mine starts as supposed: only in neutral or park.

Anyone with an idea or same issue?
I've tried searching but couldn't find anyone else with the same problem.. could it be a faulty PCM? The car starts and runs fine, no error codes whatsoever

 

[Ralph77]

Instead of tapping into the wire at the PCM I used this video for my install.
Took a trip to the boneyard for the wire but was pretty easy and made for a cleaner install IMO.
Wondering if you are using a real Ext Idle switch.

 

[Joukel]

Instead of tapping into the wire at the PCM I used this video for my install.
Took a trip to the boneyard for the wire but was pretty easy and made for a cleaner install IMO.
Wondering if you are using a real Ext Idle switch.

Thanks for your reply! I was thinking of making a connection at the transmission plug.. but unfortunately XJ's are very rare here, so I cant find any spare plugs or wiring.
Im just using a simple switch wired to the ground (I can't even find normal parts here, let alone a ext idle switch haha), it is easier to wire and troubleshoot in case of errors. But even a direct ground wire to the A12 pin does nothing, therefore making it useless..

 

[Ralph77]

If you are following the write ups that I have seen where the guys just tap into that gray wire right at the PCM wondering if your "homemade" Ext Idle switch is correct.

 

[Joukel]

If you are following the write ups that I have seen where the guys just tap into that gray wire right at the PCM wondering if your "homemade" Ext Idle switch is correct.

Well it does nothing else then shorting pin A12 to the ground, which is exactly what I'm doing, so that's strange. It's just the same as many other people have wired it