I have an electric blanket where the insulation has escaped from its clamp.

Own work

Totally easy fix, as long as you can get into the fitting. But there are no screws or anything. There are three recessed holes that look like some kind of melted plastic rivet or mushroom.

How can I open this fitting to re-place the power cable without damaging it ?

enter image description here

My plan is to drill it out a bit at a time. When closing it I would drill a small short pilot hole and use a short self-tapping screw into the plastic, and then fill the recess with something to prevent skin/metal contact. Does that seem sufficient?

  • 2
    Things like this are often made NOT to be opened by consumers. They are designed in such a way that the manufacturer can claim "consumer tampering" when the liability lawsuit is generated.....
    – Tyson
    Mar 10, 2018 at 4:14
  • 1
    Get a new blanket. Mar 10, 2018 at 4:30
  • 2
    what has happened is that the outer jacket of the power cord has shrunk .... cut off the plug from the end of the power cord ... strip away some of the outer jacket ... firmly grab the wires with one hand and with your other hand push the outer jacket towards the fitting that you show in the picture ... you have to keep stroking the power cord because the outer jacket will move very slowly ... guide the jacket into the fitting ... once the power cord outer jacket is inside the fitting, put a new plug on the power cord
    – jsotola
    Mar 10, 2018 at 5:15
  • 1
    Is this the plug on the power cord or the fitting where the wire attaches to the blanket itself? Mar 10, 2018 at 10:19
  • 1
    @jsotola, I think your comment should be entered as an answer. Mar 10, 2018 at 11:06

2 Answers 2


The fitting is press fit together, and then the melted plastic holds the unit together. DON'T use any metal screws. What has happened is your wire has come loose from the strain relief. If you did anything - attach a strain relief to the backing, push your wire back into the connecting box. Then tie wrap your wires to the strain relief that you attached.

The image below shows only the self adhesive strain relief attached to your cable connector. So insert your cable back into your connector and tie the cable to the strain relief with a wire tie.

If you pull the unit apart you might have more issues (with looseness etc.) you could do it your way and pull it apart and maybe wire tie the unit together. My advice is to get a new blanket as these things can be dangerous when they fail.

Blanket with strain relief on back


I ended up drilling the "melted mushroom" out of the holes, which allowed the cover to drop off.

Reseating the cable was literally a 5 second task. The small amount of slack wire fits inside the housing fine.

To close it up, I realised that the plastic studs were nowhere near power wires. So I drilled completely through with a smaller diameter drill, and used three thin plastic zip ties to hold the shells together. The closure of the zip ties ended up down inside the holes, so its only ~1mm thicker than it was.

Its no less safe than it was when new.

YMMV, IANAE, this may be contravening regulations in your locale, etc. Use your best judgement, but don't assume something's for the bin without inspecting. The fix may be easier than you think.

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