P/N Inhibitor - other threads don't have right info

[tuckertrucker]

Evening all

What is the location of the P/N start inhibitor relay switch?

I know the actual switch is on the side of the gearbox, but this is just the switch that tells the truck where the stick is located. And I know where the start relay is (under the cover next to the driver side battery), but again, this is just the start relay.

The inhibitor relay is the one that opens the start circuit when the gear shift switch says its not in park or neutral.

Reason for asking - manual conversion. Need to bridge it. I can cross the neutral and live wire in the auto's loom to trick it into thinking its in neutral. But I would much prefer just to remove the relay. Wagon is a 1992 GQ Safari.

cheers people

[jff45]

P/N inhibitor is on the side of the trans. It closes the circuit in P or N so the start relay can work.

[mudnut]

The manual pages EL 80 and EL 81 show the relay as 142 M under the cover next to the battery.

Page EL17 shows which wires to bridge out, but the Haynes manual is a bit different.

Edit that is for a petrol engine.

[tuckertrucker]

P/N inhibitor is on the side of the trans. It closes the circuit in P or N so the start relay can work.

Awesome thanks! I wasn't sure if it closed the circuit or just sent signal to another relay near the passenger kick panel.

[tuckertrucker]

I now see where I was getting confused - I was assuming that the start relay that uses the signal from the inhibitor switch was live with a constant 24v. But according to the diagram (if I opened my eyes and read correctly) it says that the inhibitor circuit is switched in the ignition circuit.

So when the key is on, the P/N inhibitor switch will close or open the start relay, and the START position on the ignition switch energises the relay (which will only send power to the cranker if the P/N inhibitor closes the relay)

So if I earth the WHITE wire, the relay will close when the ignition switch is moved to START, and the cranker will do its thing.

The manual says that the brown relay wire is connected to ON or START. I don't know what variants the manual covers, but in mine, it must be connected to start. Considering if I bridge the two heavy wires, the engine will crank.

Cheers for the help, i've had the manual for a few months but must have kept mis reading this page on account of it saying "gasoline engine models"

[mudnut]

tuckertrucker The Haynes manual page 16-12 shows the TD42. Yep, just earth the starter relay and bypass the switch altogether as per a manual transmission. I have amended post #3.

[tuckertrucker]

cool thanks. I don't have the haines manual dammit. Is the wiring the same for the two? I can't imagine why it'd have different wiring considering both are mechanical engines.

[mudnut]

tuckertrucker this should suffice. The two (petrol and diesel) are wired differently. M/T = manual transmission (black wire) . A/T = auto transmission (White wire which you can earth). This diagram is for TD42 1991 and later models. The second is for Carby engines. And the third is TB42 EFI. The fourth is a TB42 Carby auto.

[tuckertrucker]

tuckertrucker this should suffice. The two (petrol and diesel) are wired differently. M/T = manual transmission (black wire) . A/T = auto transmission (White wire which you can earth). This diagram is for TD42 1991 and later models. The second is for Carby engines. And the third is TB42 EFI. The fourth is a TB42 Carby auto.

so here's something interesting then - mine is auto, and its diesel. But it is certainly not wired like the haines manual says. The black and yellow wire going into the start relay is live with the ignition key ON. I know this because I crossed the two black/ yellow wire with the ignition on and the engine cranked. If it was wired as above, then the black/yellow wire will only be live when the ignition switch is in the start position.

[GQtdauto]

so here's something interesting then - mine is auto, and its diesel. But it is certainly not wired like the haines manual says. The black and yellow wire going into the start relay is live with the ignition key ON. I know this because I crossed the two black/ yellow wire with the ignition on and the engine cranked. If it was wired as above, then the black/yellow wire will only be live when the ignition switch is in the start position.

Maybe the difference between a safari 24 volt and non safari 12 volt .

[tuckertrucker]

But, I see the petrol model in the other manual clearly shows that the black yellow wire is live with the ignition ON, and its the other side of the circuit that is switched through the ignition switch. 73808
So basically, earthing the white wire will work. But my truck isn't wired as the haines manual says it is. For some reason mine is wired in the same way as the petrol circuit in the work shop manual. Maybe they did it differently in the 24v trucks cause thats what mine is.

But it is definately wired this way - we know this because when the ignition is ON (not START) the black yellow wires have power. And the white one is only live when the ignition switch is in START.

I note that neither of the manuals cover "24 volt Safari's" so maybe that's why the wiring isn't depicted above.

[mudnut]

https://www.flickr.com/photos/13765922@N02/sets/72157629319146777/ Try that site. I have found some of the diagrams for the RB30 aren't as they should be, so don't feel left out:)