Hey guys,

I'm reaching out for some advice on a couple of electrical problems I've run into with my 2003 Land Rover Discovery.

Issues:

1. A few weeks ago, I noticed that when I turn the key to the 0 (OFF) position, the radio stays ON, when it should actually turn OFF at ignition position 0. I'm aware of the 20-minute "timeout" function that the radio is equipped with, and I've included a PDF page from the manual with this section highlighted for reference. However, despite this function, the radio remains constantly ON and does not switch OFF automatically after this timeframe. This has led to the battery being drained a couple of times.
2. Additionally, more recently, the cigarette lighter outlet has stopped working altogether. It's important to note that this issue may have arised separately and at a later time than the radio problem. I checked the fuse for this circuit (located in the Main Fuse Box under the steering wheel), and it seems visually fine.

To address the above issues, I have taken some steps, described below:

1. First, I checked Relay #7 (Ignition auxiliary circuits relay) under the hood. I swapped it with Relay #10 (ABS pump motor relay) to see if it was a relay issue, but no luck there.
2. I also inspected the radio-related fuses in the Main Fuse Box (Fuses #16 and #17). They seem visually fine.

I have a set of tools and a multimeter at my disposal, so I'm ready to perform any suggested actions to troubleshoot these issues further.

I'm hoping some of you might have encountered similar situations or could suggest some next steps for diagnosis and a potential fix.

I'd greatly appreciate any insights or advice you can share.

Thanks a ton for any suggestions

 

So, after mustering the courage to remove the center console, I was able to remove the cigar lighter out of the console (took a lot of effort) and test the cables to the cigarette lighter themselves, since I was getting good voltage on Fuse #15 but not on the lighter outlet itself i was hoping for a faulty outlet and turns out the cigar outlet is faulty since I am getting "good" voltage on the wires. I'm now in search of a suitable aftermarket solution. Does anyone have recommendations for replacing this with, say, two USB outlets equipped with a voltage reader?

As for the radio issue, I'm still stumped by its refusal to switch off. I'll continue my testing and troubleshooting and will provide an update soon.


wiring to the cigar outlet seems to show OK Voltage.

 

It appears your meter is set to millivolts?? 14.8 is a bit of an odd reading. If the truck is running I think you might see low 14s but engine off would be closer to 12v.

 

Oh my! you are ABSOLUTELY right!! , this multimeter auto adjusts and I hadn't noticed the "m" before the V when taking the reading at the cables in the cig outlet. It does look like I am getting 14.09V at the Fuse #15 but 14.8mV at the cig outlet. Somewhere along the route of the wire from the fuse box to the outlet I am losing volts!. I'm including pictures of the meter readings (2 from the Battery (ON and OFF) and 1 from the reading at Fuse #15.

What should I check next?

Thanks for spotting that and for your amazing attention to detail!.


Reading at Battery (Ignition OFF)

Reading at Battery (Ignition ON)

Reading at Fuse #15

 

While you have the console and the lighter out, I suggest rewiring it so that it is always hot.

This may not be valuable to you, but I did this years ago so that I could charge a device without the key being in the truck with the ignition switch at Position I. This was useful at scout camp and other occasions.

To do it, I used an Add-A-Circuit plugged into to an always-hot fuse location in the fuse block behind the panel behind the steering wheel, and ran a wire to the lighter I bought at NAPA to replace the original that is a little oversized for American accessories.

 

Hi @mln01 , Thank you very much for the suggestion. You gave me a good idea and I am ordering that suggested Add-A-Circuit. Quick question though, I have ordered on ebay the following Car Charger as a replacement to the existing cig lighter eBay, since this has some illuminated LEDs, do you think that will have any significant draw on the battery if i leave it connected to an ALWAYS HOT circuit? Also, just out of curiosity, any idea on how much car battery draw when charging a phone if car is not running? (Just want to get a sense of magnitude so i don't end up completely emptying the car battery by keeping/forgetting a phone plugged in there).

One more question, and apologies for all of the questions but I am doing this for the first time and want to get it done right, what do people use as connectors to plug into the connectors? what about cable size? the RAVE schematics talk about 1.5D , does is that 22 AWG American Equivalent? (attaching photo from the Electrical Circuit Diagram for this wire)

 

First, hoping to not be condescending, I commend you for diving into the Electrical Circuits PDF. I found it intimidating years ago but it is now a frequently used resource.

The table found at this link shows that 1.5mm2 is the equivalent of 16AWG.

https://www.lapptannehill.com/resour...nversion-chart

The Add-A-Circuit may be found locally; you may not need to order it.

As for current draw, you didn't include a link to the car charger you plan to order. Regardless of that, I think the substantive answer to your question depends upon how you use your truck. If it's a daily driver, the always-on draw of the device is likely inconsequential. If, however, your truck is driven only once a week or less often the device may drain the battery more than you'd want.

I use a plug-in USB charger (pictured). With it, I can simply remove it from the lighter socket and kill any current draw. No need to get all fancy.

 

Also, the fuse is sized to protect the wire, so if the original is 16 AWG, you should use 16, or larger wire (eg, use 14 but not 18).

 

Pull the radio, leave the cables connected! and put the positive probe of the multimeter (negative connected to ground of course) directly into the connector holes. Check if there is 12V at the "permanent battery feed" (C0098-4) and that 12V goes on and off with ignition at the "auxilary feed" (C0098-7). The radio should turn off as soon as there is no voltage at the "auxilary feed". Maybe there is a shortcut or someone messed with the wiring.

 

Thank you for this, I didn't know if the 1.5D was in mm or mm^2 for the Land Rover Schematics. I also felt that 16AWG was a thicker wire than the one i can currently see installed but I guess it won't matter much.

I'm including below the outlet USB socket I decided to go with, this includes an ON/OFF switch so when I wire it to an ALWAYS hot fuse I can decide to keep it OFF (or ON). I do not use this vehicle much so having the ability to cut power to the outlet may safe me from potentially emptying the car battery (though unlikely).

I am happy to report that I was able to identify the issue I was having with the wiring arriving to the cigar outlet, somehow I must have had a bad ground connection, I was able to locate the earth point (by the passenger A-Pillar) and wiggle the wiring there a little and bam! got the power back on at that outlet. Now I only have to wait for this USB outlet to arrive and will rewire it.

Thank you for this suggestion! I am so thankful to this community for posting very useful mods and hacks that we can include to these amazing vehicles!

Off to carry on trying to figure out what is wrong with the radio not turning off when I turn the ignition OFF.