Vr clubby auto neutral switch issue

[sfinglas]

Hi all, I have recently acquired a vr clubby and it was fitted with a B&M shifter. Im currently returning the car back to factory specs and in doing so have discovered that the neutral switch and reverse lights control isn't functioning. i can earth the switch out to the body and get the car to start but in doing so it will then be able to start in gear which isn't right. I can also bridge the reverse lights with a power source and get them to work so i know the circuit is complete after the switch. i have power at the reverse light/trans control fuse so i know that it's also a complete circuit. so my question is this. what else in play that would:
1) prevent the neutral switch from operating correctly/receiving a signal (pcm bcm, trans or other influence??)
2) what is in line on the reverse circuit between the reverse fuse and the reverse switch that would stop it from receiving signal/power?

i have check all wiring that i can access without actually removing the dash from the firewall of the car and found nothing suspect.
Any help on this matter will be muchly appreciated as I'm starting to loose hair over this issue haha.

[Micks]

Is the switch you have an OEM one? If OEM & correct is it adjusted properly eg aligned to the appropriate gates Pk N R?

[sfinglas]

Yes mate it is the correct one and I have check the switch with a multimeter to ensure it is working at the right orientation.

[Micks]

Ok if all is correct & adjusted properly but still not working (electrically) the switch must fukked then.

[sfinglas]

Hey mate, cheers for the reply. it's not the switch as I have tried three separate switches with the same result. All switches are oem and have correct alignment. Plus I tested each switch to make sure they definitely weren't stuffed or wrong orientation.

[Micks]

Doesn't make sense as you mentioned above if the connections are bridged the inhibitor allows starting & reverse lights work too??

[dnos]

In my experience with the NSS switches on 4L60e transmissions the park/neutral switch needs to be grounded for the car to start, however it only finds "ground" when the gear selector is in P or N. Can you test this with a multimeter? i.e. does your wire and ground make a connection in N and P?

My thoughts are the same as Micks, either your switch is fragged or grounding for the switch itself is bad.

With reverse, it creates a 12v circuit so obviously you need to get power to the NSS switch and make sure 12v comes out of the loom when in reverse.

[dnos]

And test it from the PNP wiring loom itself... before it gets into the BCM and whatever other wiring carnage there may be.

[sfinglas]

Hi mate, Ok so from your info I suspect the grounding down stream from the switch is bad, were would it be grounded to exactly? I have tested the switch with a multimeter when in park and neutral and it sees a complete circuit hence why I suspect the issue is down stream from the switch.

As for reverse I'm not getting 12v at the switch at all, I'm aware it needs it to work but my issue is why haven't I got it at the switch. I have power at the reverse/trans fuse but I'm unsure what is in line between the fuse and the nss on the reverse light circuit that could interrupt the signal. You mention PNP? What is that exactly?

[Micks]

Sounds like a circuit diagram may be your friend :yup:

[sfinglas]

I've got a manual with the full circuit diagram but it doesn't elaborate as to where things are earthed to or exactly where wiring goes, that's why I'm stumped, for eg the reverse circuit according to the diagram runs straight from the fuse to the switch and then straight to the reverse lights but when I check the back of the fuse there is two separate wires running from it that disappear into the main body loom, one goes to the trans but at some point one of the wires splits then returns into the cabin which would suggest it goes to something else (not notes on the diagram) before it goes to the nss.

[dnos]

Maybe the NSS doesn't have ground or 12v? The only real way to bust this one out is by getting the colour scheme for the wires coming out of the NSS, stripping them so you can get a multimeter on to the wire and testing the NSS itself.

Also, how many wires and whats the shape of your plug and NSS? Can you send a pic?

[sfinglas]

Sorry, unable to post a picture. But the plug is a square plug with four wires
Grey: when earthed car starts
Grey/blue stripe: earth wire for start function (bad earth maybe preventing from starting?)
Pink/blue stripe: power source to nss for reverse
Green: feed from nss to reverse lights

The pink wire has no power on it at all, I have unplugged the nss from the loom and tested the loom plug for power, it has none with ignition on. Is there a solenoid in the trans that switches this feed on when reverse is selected maybe? Same for neutral and park?

[dnos]

Sorry, unable to post a picture. But the plug is a square plug with four wires
Grey: when earthed car starts
Grey/blue stripe: earth wire for start function (bad earth maybe preventing from starting?)
Pink/blue stripe: power source to nss for reverse
Green: feed from nss to reverse lights

The pink wire has no power on it at all, I have unplugged the nss from the loom and tested the loom plug for power, it has none with ignition on. Is there a solenoid in the trans that switches this feed on when reverse is selected maybe? Same for neutral and park?

That could be your issue. Perhaps the switch itself is not connected to the 12v and earth it needs. Also, it works off the shifter position from that bolt that sticks out of the side of the trans.

[sfinglas]

Also I have bridged the grey wire straight to the grey/blue wire on the loom itself and it still doesn't start so it's definitely not the switch.

[Micks]

Also I have bridged the grey wire straight to the grey/blue wire on the loom itself and it still doesn't start so it's definitely not the switch.

Very difficult to diagnose wiring faults over the net, can I suggest as you have a wiring diagram is obtain some loose insulated wire then disconnect your current loom & replicate point to point as per the circuit diagram & post back your findings? Appears to be all but four wires anyhow.