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RX 400h Electrical Gremlins? It Might Just Be a Hidden Water Leak

Apr

2025

Electrical gremlins on an RX 400h often trace back to a water leak, not a wiring fault. Here's what we look for and where water gets in.

They’re the sort of car that people want to hang on to, and why not?

The problem is, like any car that’s getting on a bit, they’ve got a couple of niggles. One of the main ones we see is water getting into the boot. Nothing major at first, a bit of damp, carpet’s wet -- but if it’s left, that water creeps forward and gets into a relay box next to the hybrid battery. And once that gets wet? Bang -- warning lights on the dash. Hybrid system fault, red triangle, you name it.

Lexus were clever with the battery itself -- they gave it its own little drain. But the relay next to it? No such luck. No drain, no protection. So once water gets in there, it’s only a matter of time.

Now, don’t panic. This isn’t the end of the road for your RX. What we do at New Again is fix the leak properly. We dry the car out, find out where the water’s coming in, and sort it -- all part of our Car Water Leak Service.

Let me tell you about Hybrid Repair Service Ltd. Mark is an amazing chap we work with who knows these cars inside out. He's mobile so he’ll come to us -- or your home if needed -- and replace that relay or even recondition the battery if it needs doing. Job done, all in one go.

Using a random orbital polisher — Here's a 2007 model we have with us at the moment for a leak repair. It's in lovely condition, but has a scuff on the bumper -- that's precisely the kind of damage we can fix.

Of course, you do need to get the leaks fixed before you can repair the electrics -- we've done loads of these over the last few years.

While it’s in, we often give them a bit of a refresh too. We can polish up the outside, clean and condition the leather -- bit of love and attention, and suddenly, it feels like a new car again. Or at least, like new again. Which is the whole point, isn’t it?

So if you’ve got one of these lovely old RXs, or any of the Lexus Hybrids, and it’s starting to show its age -- maybe a few warning lights, or just a bit scruffy -- don’t be too quick to write it off. Give us a call, have a chat, and we’ll help you get it sorted. You’ll fall in love with it all over again.

by Gary Wray
Business Development.

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