FMS FCX10 LC80 lighting upgrade

FMS FCX10 LC80 lighting upgrade — Rear Lights, Spotlights & Custom LED Mod

If you’ve spent any time with the FMS FCX10 LC80, you’ll know it’s a cracking little crawler with loads of realism. But one thing that’s always bugged me — and plenty of other owners — This car needs an FCX10 LC80 lighting upgrade straight out of the box.

You get headlights, spotlights, and brake/reverse lights, but no rear running lights. When you’re out crawling in the dark, that makes the back of the truck almost invisible.

So in this guide, I’m going to show you three lighting upgrades:

1. The easy fix — get rear lights working using the stock lighting block
2. The spotlight control mod — switch spotlights on/off independently
3. The full LED upgrade — add proper rear running lights using a custom LED harness

Let’s get into it.

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Why the FCX10 LC80 lighting upgrade is needed

Out of the box, the LC80 only lights up the rear when you brake or reverse. That’s fine for daytime crawling, but at night it’s a pain — you can’t see the back of the truck, and it kills the realism.

My preference is rear running lights, but yours might be brake lights only. The good news is: the LC80’s lighting block gives you options.

Part 1 — The Easy Fix (No Tools Needed)

Inside the rear of the LC80 you’ll find the lighting block. It’s easy to access and clearly labelled:

• Indicators port 1 & 2
• Headlights Port 4
• Brake/Reverse Port 6
• Spare ports Port 3 & 5

The quickest fix is simply moving two plugs:

1. Slide Main headlight Plug containing 3 wires into DRL 3 Port 3.
2. Move the Reversing/Brake light to port 4

That’s it.

Now when you switch the LC80 on:

• Headlights work on switch
• Rear running lights will work on switch
• Spotlights will work on switch

If that’s all you want, job done. But we can go further. This solves the problem of no rear running lights, but what if you want more. By a simple change of wires, you can then turn the spotlights on and off. Once the headlights and rear lights are engaged you can the turn the spotlights on and off.

Part 2 — Spotlight Control Upgrade

The next step is making the roof spotlights switchable, instead of permanently on.

This involves:

• Separating the brake light cable
• Re‑routing it into position 4
• Adding a small custom adaptor to extend the cable
• Moving the reversing lights into the spare port

Once connected, you get:

• Headlights + rear lights
• Spotlights on/off independently
• Brake/reverse lights still working

This is a brilliant upgrade because it gives you proper control over the LC80’s lighting behaviour — much more realistic.

Part 3 — Full Rear Light Circuit (Custom LED Build)

Now for the fun bit: adding proper rear running lights using a custom LED harness.

What you’ll need:

• 3mm LEDs (Amazon pack of 120 for a tenner)
• Extra wire
• Heat‑shrink solder sleeves
• Heat gun
• Crimp connectors
• Glue gun
• 4mm drill bit

Building the FCX10 LC80 lighting upgrade LED harness

You’ll splice:

• Both positive wires together
• Both negative wires together

Then secure them using heat shrink solder sleeves. These melt, shrink, and solder all in one go — perfect for RC wiring.

Once the harness is built, crimp on your connectors so it plugs straight into the LC80 lighting block.

Installing the LEDs

Inside the LC80’s rear light housing:

1. Remove the 1.5mm hex screw
2. Drill two 4mm holes
3. Feed the LED wires underneath
4. Hot‑glue the LEDs in place
5. Cable‑tie everything neatly

FMS did a tidy job with the wiring, so try to match their neatness — it looks better and avoids snags.

Final Result — Full Lighting System

Once everything is back together, here’s what you get:

• Headlights
• Spotlights (switchable)
• Rear running lights
• Brake lights
• Reverse lights

Everything works cleanly, reliably, and looks far more realistic than the stock setup.

This is how the LC80 should have come from the factory.

What’s Next?

My next job is getting the front bumper spotlights working — another mod that really completes the LC80’s lighting package.

If you enjoyed this upgrade, stick around — more LC80 mods, crawler tests, and honest RC reviews coming soon.

Thanks for reading, and as always: like, subscribe, and keep your RC honest. 

Check Out the Review of the FCX10 LC80 HERE