Drivers seat upholstery removal/refit (1 Viewer)

[rwg]

Hi folks,

I have a non-working seat heater on the driver's seat, which I've so far tracked down to a break in the wiring of the heating pad on the seat base. In order to work out if it is fixable (or to replace the heater pad), I need to get the upholstery off the seat base and be able to refit it.

So far I've dealt with the plastic clips front and rear that stretch the seat upholstery over the foam and the velcro straps that tie it to the side bars of the seat. That gets me to the point that I can peel back the sides/back/front of the upholstery and see that it is fixed to the foam like this

The black plastic looking strip is attached to the upholstery, the wire with the loop at the end is attached to the seat foam. I think the right thing here is to cut the copper coloured loops (hog rings?) and then replace them later using hog ring pliers and new rings. Is that right? The only other option would seem to be to unfold the loop at the end of the thick wire and unthread it from the various fixing loops.

Also, does anyone have any idea of where to get hold of matching (or similar) heating pads? The current wiring has the pads in series with a total resistance of about 4 ohms - rougly 2 ohms per pad. I picked up some cheap pads off of Amazon, but they are 8 ohm resistance, so obviously designed to be wired in parallel. I could re-do the pad on the seat back too I guess and then re-jig the wiring for parallel pads, but would prefer not to.

cheers,

Robin

 

[Mike800966]

The "hog pins" (lovely name) may have sharp points but from my experience with volvo seats in the past, you should be able to bend them off with two pairs of pliers then you can re use them!
Mike

 

[rwg]

Hi Mike,

thanks - glad to hear I am on the right track. I actually bought a set of hog ring pliers with a selection of different size rings off of Amazon for about £15. Haven't found time to actually take off the covers fully yet, but it sounds like I am all set to at least be able to refit them when I do!

cheers,

Robin

 

[rwg]

Just to update this, I actually got around to replacing the heating wiring a week or so back, but this weekend was the first test on a trip and - for the first time in the van - I had a lovely warm backside on a cold morning!

Getting to the heated seat pad involved cutting the copper coloured rings, which I did with a pair of wire rope cutters. Only need to do one side, then you can peel the seat cover back (also needs to be unclipped from the tension clips front and back). Be careful not to pull the self-adhesive velcro out of the grooves in the foam.

You can see a couple of places where I tried previously to get into the wiring of the oroginal heater element to see if I could work out where in the element the break was. All I managed to do was break the wire more, since it was quite fragile...

I had initially planned to buy a new heated seat pad, and in fact I ordered a set, but when they turned up they were obviously designed to be wired in parallel (since the individual pads had a higher resistance - about 8 ohms I think). I could have used them, but it would have involved replace the one in the seat back too... I decided on an alternative approach and ordered some heating wire from China (https://www.ebay.co.uk/itm/26599298...d=link&campid=5338547443&toolid=20001&mkevt=1) - with this at a resistance of 0.3 ohms per meter, I could just cut the length I needed to match the resistance of the broken pad. From the passenger side, I measured this at about 1.3 ohms, so just over 4m of wire was needed.

My original plan was to feed the new wire through the fabric of the old pad, but that turned out not to work so well - every time I made a hole, it was pulling the adhesive away from the foam below.

The revised plan involved using tape to secure the wire in roughly the right pattern and then sewing it to the original mat at each corner with a single stitch of strong thread

This worked out fairly well. Note that the heating wire goes underneath the heavy duty wire running up/down in these photos, since the seat cover will need to hog tie into that wire. The two ends go out the back of the seat to be wired to the plug from the old heating pad.

I used masking tape on the grounds that if left it actually usually sticks quite firmly, and I have never seen the adhesive migrate out from under masking tape as you sometimes see with electrical tape or gaffer/duct tape.

The chinese heating wire was considerably more robust than the wire in the original seat heater - it has the red plastic insulation coating and inside that a very fine wire that is twisted round a bundle of fibres (nylon?) to give it some strength. I cut off the plug from the old seat heating pad, stripped the ends of the red wire and connected then together with Wago connectors, which worked fine.

Replacing the seat cover is the reverse of removing it as they say - getting the new hog rings in was a bit fiddly, but Ok after a few tries.

If you run your hand over the seat base you can feel (just) the bumps from the red wire as it is thicker than the wire in the original heating pad. You certainly don't feel it when you are sitting on it though.

Anyway, all seems good for now, let's hope the repair holds up.

cheers,

Robin