Hi everyone, I’m trying to identify a 12V constant source that I can tap into on a 2003 fuse panel (the panel by the driver’s feet) - I can’t make sense of the manual and diagram to figure this out. If anyone can name a fuse number that can be used, I’d appreciate it! The car battery is dead and I can’t start it, so I can’t identify anything by probing or anything like that - I’m hoping someone just happens to have this knowledge already and can help me out. This is needed to be able to connect an oil pressure gauge. I’d planned to use F11 for the “headlamp” source that’ll dim the gauge when the headlights are on - and I’m planning to use F26 as the 12V switched source. The “add a circuit” I’m using wouldn’t allow me to use two fuses that are right next to each other, since they cover the next 4 fuses or so down the line when installed, so it would have to be something that’s still accessible with those fuses used already, or if it’s the only 12V constant available, I’d appreciate help locating alternative fuses that can be used rather than F11 and F26 if they get blocked by something else. I was told the clock is on a constant, but not sure if it’s 12V and wasn’t sure where it’s fused exactly, although I believe it’s F10... Can I use these fuses safely? The add-a-circuit’s will use 5V fuses.

Thank you

 

There's an open socket at the lower right that has (I think) both switched and constant 12v. I was able to buy a plug that fits into it.

 

Here is a link to a thread that I keep handy. I know its "switched power" but it also calls out a few things that are constantly on and where to draw power for those contacts.
https://landroverforums.com/forum/di...e-my-d2-68943/

I think fuse 20 is constantly connected. At any rate- connecting something to a permanently on circuit is fraught (in my opinion) because you risk the item slowly draining your battery, and you already have a dead one! Why can't your oil pressure gauge be plugged in to a switched source? Perhaps we have a vocabulary confusion- when I refer to a "switched power source" I'm talking about something that is energized when the car is on and shuts off when the car is off, not necessarily a power source that goes through an actual user controlled switch (although it can) switch.

 

Do you have any recollection where you bought that plug from? It would come in handy!

 

There's info here: https://landroverforums.com/forum/di...2-68943/page2/
Apparently it's the same connector as the windscreen wiper motor so if you have a parts vehicle, you might be able to harvest a couple.

 

Thank you - apparently the Glow Shift oil pressure gauge requires 12V constant or it'll lose the color illumination setting, which isn't important to me, but only the needle will illuminate and it won't be backlit... I guess I could just connect it without the constant connected and use it on switched power. This is mostly important to get working before the vehicle is started again since it will have a new oil pump and I need to be sure it has pressure right away. I don't think it'll drain the battery quickly when it's being run regularly again, but I would prefer that it just used a CR2032 battery to hold the illumination preference and just used switched power to illuminate the entire gauge (apparently the needle itself and the dial are illuminated in different ways - that's what Glow Shift told me, at least).

It looks like F20 will work, but I'm a bit confused since I'm not great with wiring diagrams... Perhaps someone can help make sense of this? I'm unsure if I'd use F16 or F20.

 

Thanks - I'd heard about that before, but wasn't so clear on it. I'll have to check out that plug. I've been told I can simply add a circuit for 12V constant in the fuse box under the steering wheel, so I'm trying to go for that option since it'll be easier for me before wiring a plug, but I might have to look into that more if I can't figure this out any other way.

 

Use fuse #20

 

Thanks for that. I believe I am doing the same oil gauge and water temp set up as the OP.

https://landroverforums.com/forum/di...isco-ii-33978/

There are two add a circuit fuses in this one for black and one for yellow.

You are saying to use Fuse 20? And?

 

I ended up using the fuses as shown in this video -
Apparently some aren't truly constant as they shutoff when the ignition is switched, but F2 (fuel door) is supposedly a true constant... I really don't know any better and haven't started the vehicle yet to see what's going to happen (need to put the new oil pump on before I can do that) - I'll just see what happens at that point, but that's what this video advises. I used 5A add-a-circuit fuse taps - I'm not sure if there's a maximum they can handle with regard to the original fused circuit, but I believe all of the fuses are on 10A or 15A circuits... I'll find out a lot of things when I start the vehicle and see what happens - if any fuses blow, etc.

Yellow (Constant) - F2 - Fuel Door
Red (Switched) - F15 - Cigar Lighter
Orange (Headlamp) - F33 - Parking Lights
Black - (Ground) - this doesn't need to be fused - it turns out that I discovered the same grounding method that that other link shows. You'll just need a bit more wire to reach it, so solder or buttsplice some more wire on with a ring terminal on the end of the wire and put a grounding screw in that empty* welded screw hole shown in the link you shared.

*mine was empty and it seems it's just that way if others are doing that as well without making it so their dash is missing screws.

Hope that helps - by the way, I'm not any kind of expert, just sharing what I did after having to learn a lot to do this, which I believe is done correctly... I wish I'd just seen that video and that link sooner because I think I wasted a lot of people's time. If I were smart, I would have installed a water temp gauge at the same time since the miserable 18-22 gauge wire on the Glowshift gauge made it tough to get a good connection (tug test) using red buttsplice connectors. I'll probably cut them all off and solder/heatshrink tube the connections later after seeing that the circuits used are good. Another option is to install a water temp gauge at the same time so you've essentially got double the amount of wire going into the butt splice connector to give it a better connection when you crimp the buttsplice.

Oh yeah, I cut the blue buttsplice connectors off the add-a-circuit fuse taps (they all seem to come with 14 or 16 gauge wire and blue butt splice connectors) and used red butt splice connectors to be able to splice the 18-22 gauge wire from the Glowshift wire snake.

By the way, I didn’t drill anything in the dash, just managed to sneak wires as shown below, but it’s not easy and you’ll probably leave blood behind like I did. I’ll have have to convince myself if I really want to do any of that again for a water temp gauge - might just use OBD for that since you can get that data there (can’t for oil pressure, so you have to install a gauge). I ran the oil pressure sensor through the rubber bulkhead as shown and it sealed itself back up pretty well, but I’ll gloop some black silicone on there anyway. I plan to put the oil pressure gauge in the same type of mount that’s shown in the video - just stuck it up there for now.