The van’s fairly old (54 plate), the stereo’s not the original but is probably ten years old too. I’m getting increasing interference when I’m listening to the radio and the wipers are on, is this cos the stereo’s getting worn out, or something on the van is wearing out?

Most likely a breakdown on emf suppression in the wiper motor due to age/wear on the motor, a simple fix may be a ferrite clamp over the power cable or use a suppressor

more detailed info on how to cure here

Interesting, I have interference when I plug my phone in to charge 🙁

One of these ferrite clamps will work, you can buy them singly from the likes of halfords etc

I used to get this all the time years ago, back in the days of aftermarket DIN-E stereos and cars from the 1980s. It’ll either be a) poor earthing of the head unit or b) require an inline suppressor (basically a big capacitor) on the power feed to the stereo.

Does it do it only with the wipers or other electrical kit like windows, rear wiper, heater blower, lights etc.

If it is only the wipers then check their earth is sound. If needs be, run a temporary wire from the negative off the wiper motor directly to the battery. If it stops the noise, run a new earth cable in or try trace the rust / bad contact between the motor and battery.

You could simply try putting a piece of cable at least the same diameter as the one already there between the battery negative and car body – replicating the factory negative strapping. Sometimes this helps of the factory connection is getting worn / corroded.

If it had interference on all the cars electrics, run the negative from the stereo direct to the negative battery terminal and see if that helps.

I used to get this on an isuzu trooper on AM stations if you turn the volume up and wind all the windows down you can pretend you’re flying a Sopwith Camel

I get radio interference when I plug my dashcam into the cigarette lighter. Any ideas?

It’s in your head, or it’s in the head of the ghost sitting right behind you 🧟‍♂️🥴

I was going to suggest a bad earth, does the stereo have a proper adapter cable or is it a twisted wires wrapped up with sellotape job?

I get radio interference when I plug my dashcam into the cigarette lighter. Any ideas?

As above…you need to fit a ferrite clamp around the power cable, as close as possible to the dash cam

Wiper motor is possibly worn and sparking. A capacitor soldered across its terminals should sort it if the suggestions above don’t (they’re simpler) 🙂