Blowing a major fuse suggests that your car has suffered a short-circuit somewhere within its kilometres of wiring. But a modern vehicle like your Isuzu will also have fuses protecting the various systems it needs to operate, so there’s a chance there’s a second fuse that protects the stereo system that has also blown when the problem occurred. Your owner’s manual should be able to identify the locations of the car’s various fuses. Don’t forget to replace them with a fuse of the correct amperage or you could cause more damage if the fuse ever needs to act as a circuit-breaker again (which is exactly the fuse’s role).

The other possibility is that the stereo unit itself has an internal fuse. Check around the rear of the unit (usually where the wiring for the speakers exits the stereo) and you might be able to locate the fuse in question. This is often the case in aftermarket stereo systems.

The D-Max is pretty well regarded in the trade for its ability to go the distance, but modern, common-rail diesel technology has shown that a vehicle with fewer kilometres is usually a better bet than one with more. Although they do an amazing job in terms of power, torque, towing and fuel economy, today’s turbo-diesels are pretty highly strung in some ways and really need their maintenance. And the older they get, the more attention they seem to need in terms of new injectors, filters and pumps.

A D-Max with those kilometres might be ready for a pretty big (and expensive) service, too, so make sure your first trip in it isn’t going to be to a workshop. Ultimately, price, condition and service history should steer your decision as they should in any second-hand vehicle purchase. I’d take a vehicle with 150,000km with a full service history over a 60,000km one with no service records.

It’s true that diesels are at their best on longer trips when they are fully warmed up and not accelerating and decelerating all the time. You can have problems with the DPF clogging up and not regenerating if the car isn’t getting up to speed for any length of time. You could take it for a run on a highway or freeway once a month or so to get fully up to working temperature, so the DPF burn-off car hopefully happen. If the burn-off doesn’t happen automatically you face the prospect of having to have the dealer do it manually, and that would involve a cost.