2017 defender acts like battery dead

[sdg3205]

Hey folks,

Today our defender was running fine. Parked it, an hour later came back and it acted like the battery was dead. No accessories work, no action on dash, only a small click from the relay in the front storage box.

 

we checked and reseated all the fuses and relays in the front and under the seat by the battery. We tried jumping it with two different batteries. I reseated the battery cables on the terminals. Still acts like battery is completely dead except for the relay click when the key is turned to start
 

very bizarre. Any ideas?

[CampHamp]

 

I'd first look at fuses and wires for burn-outs or mouse bites. I'd check headlights and taillights with key on ACC mode (they have separate fuses). If those work, but other accessories are out, then inspect the 40A accessory fuse (the 2020 has that fuse). If it's blown, then you probably have a short in your wiring or in a piece of equipment. Maybe it's a failed starter motor.

With a multi-meter you could check to ensure no connectivity (no short) from the accessory + post to ground. It sounds like it is not the battery, but you can measure you battery's voltage while you're at it.

 

Edited February 20, 2022 by CampHamp

[Mark in Colorado]

Hey there – I just read this and had a similar problem about a month ago with my snow blade relay system. I know that sounds odd, but the point is that when I crawled under the dash I managed to tighten the main bus nuts on the main power strip - Due to all my tinkering they had worked loose. I simply tighten them, and all of the gremlins went away.  There are 3 - And you have to remove a small plastic cover to access them. This is where you would tie in accessory lighting, etc. and things that you want to add to the vehicle. One post is a common, One is a constant power, and one is a key-on power.  Good luck. I hate this stuff, but it seems like it was my own fault and I was lucky to find it. – Mark