Hi everyone,

I’m trying to wire an oil pressure gauge and I’m wondering if the location marked with a red arrow in the image below is a good place to run the wiring between the sensor on the timing cover and the dashboard where the gauge will be mounted.

I tried to pull at the rubber part, but it seems like it’s really in there and I don’t want to ruin it. I was planning on removing the tape around the wires that go through the rubber, adding the sensor wiring, taping it again and putting the rubber seal back. Do I need to pry it out? I could also poke through with a screwdriver and then seal around the wire with silicone - or I could find another route through. I’ve seen some people drill through the metal somewhere nearby instead, but I’m always worried I’ll hit something and I’d rather do this without doing that.

Also, does anyone know where I can ground the gauge that’s near the fuse box behind the steering column access panel? There are some nuts there that are welded to the metal, so I can’t get a grounding terminal under those nuts, like I’d thought I might at first.

 

So I studied things for an eternity on my last Disco. When I did my oil pressure gauge (just a simple sandwich one off the oil filter- yes i know not the best, but I was just verifying doom and gloom, not perfection) I actually got juice- switched and non- and ground from this connector plug in the dash fuse block (the one just above the 30a green fuse) :



The connector- after a trainload of research- is the same as one going to a windshield washer motor:



I’ve got the pin out somewhere, but you can do the meter dance as well to figure it out. This was the cleanest and easiest way I’d found.

To get the wiring in through the firewall, I ran it and the wiring from the relay box I built and put under the hood, through on the passenger side. It was really easy in that D2 as it was non-SAI, so access and visibility was great. The same ways to get through the firewall are there on SAI engines, but it might be easier if you remove the pump first. You’ll see it as there are nipples that can be clipped off and wiring run through in order to get it through.

 

The boot/grommet to which the red arrow points in your pic is where I poked through to run a wire years and years ago.

I recommend you don't overthink it. Just poke through it (maybe with a nail?) and be done with it. No reason for tape, silicone or anything else.

Your truck is not an Apollo space capsule.

 

Thanks everyone - I just pushed the wiring harness from the sensor through that rubber bulkhead after creating a hole with a screw driver. It’s tough getting the wires where you want them without drilling (didn’t want to drill through the dash) since the access areas are really jammed with wiring or the fuse box, but I managed after a while. There’s a bit of an opening where I managed to fish the wires out just beneath the slim vent on the left of the dash - it’s tough, but it’s possible with a lot of patience, some prying, much squeezing, much cursing, etc.

The wires and gauge are just thrown in for now - the brass bracket included doesn’t hold the gauge well, so I got their other mounting dealy. Not the nicest, but it’ll just be nice to know if the (new) pump and everything else is somewhat ok. A better way would’ve been to run the wires above the stereo and have a few gauges in a pod mount there - definitely oil pressure and water temp and maybe something else. I might do that in the future, but I’m just trying to get things going for now. Tearing out the dash might be necessary to get the wires right where you want them or if you can manage to pull them through anyway since it’s not easy because of the tight spaces you’re working in without pulling panels off.

 

Does anyone have any tips for grounding inside the steering column access area? The nuts holding the box onto the frame are welded on there - I was told to use these bolts and look at the from the bottom (guessing that means to run the wire outside the access panel?) - I’d like to try to keep the ground wire inside the panel though.

I would’ve used one of those plugs but I know it’ll be tricky for me to find it and determine the pin out. I’m just in a bad place tearing apart my house and I’m trying to make certain things with this car a bit easier, although I wouldn’t want the ground wire sticking out from the steering column panel.

 

I found this - maybe I can just screw one of these into the plastic somewhere in the access panel and put the ring terminal on it? Anyone use these?

 

It seems to me you are overthinking this. For the effort you are putting in, and where you are in the process, that plug I mentioned would be easiest. It would take less than 5 minutes to determine the pin out and you could probably find one from a parts truck super easy.

I mounted my gauge in the same place as you with a sticky mount and it worked just fine.

 

Nice one - I’m waiting for that same mount to arrive. I wanted to use double sided tape rather than screws in case I wanted to move the gauge to a cluster of gauges above the radio later, so I wouldn’t be drilling out the dash everywhere.

Do you like the OBD gauge you’ve got? I’ve seen some folks use a Bluetooth connector and smartphone or a variety of other types, but I’d rather not have to have a phone dedicated to that that I’d have to wire up and keep charged. Doesn’t the gauge you’ve got drain the battery if it’s left connected, though? When I connect my scan tool, it powers up even when the key is out.

Yeah I’m sure I’m overthinking, but it helps me to get more information in case I’m having trouble installing in one way, so I’ve got another way to approach this. I’m connected using fuse taps for now, but I could look for that special connector and rewire the gauge later on. Don’t you still have to connect it to the “headlamp” in some other way or is that also in that S12 port? I’d also have to charge the battery to check what’s happening with those pins and the car can’t be run until the new oil pump is in it, which is coming up right after I get all the old wire tubing off and redo that mess while I’m able to access more of it.

 

As for a grounding point near the passenger compartment fuse box, I just put the ring terminal at the end of the wire I wanted to ground over one of the bolts holding the hinge for the access panel that runs through one of the welded nuts you mentioned, and then put a wingnut over the top of that. Any nut would do; I just happened to have a wingnut and it will make removal quick and easy if I ever want to do that.

 

Thanks, that looks good! I'll see if I can find a nut that'll fit those bolts.