We've had periodic problems tightening the harness on our Britax Blvd CS seats. It would become almost impossible to tighten, even though there'd be lots of slack left.
The two obvious culprits were the CS mechanism (the tightening rachet that clicks, which most of us don't think works all that well) and obstruction in the harness strap path behind the seat.
I'm pretty sure the problem is obstruction in the harness path. It's hard to say for sure, since it's hard to replicate when the seat is out of the car.
Here's what I think is going on (at least on my seats): the thing you tug on is a single strap that goes under the seat and up. It's joined to the shoulder straps by a "harness yoke", a kind of metal clip. It passes by various things, and in particular a plastic piece that the manual calls a "belt guard." I think that occasionally the yoke gets caught on the guard. When that happens, it's almost impossible to tighten, even with quite a bit of slack left.
The solution for me is to start over again: completely loosen the harness and then try to tighten again. That works because the yoke gets unstuck.
I also noticed that the chance the yoke will get hung up increases quite a bit if, when starting out loose, one shoulder strap is pulled out as much as possible and the other isn't. That makes sense, since I'm pretty sure the yoke is getting caught on one side of the guard or the other.
None of this applies, obviously, if the harness is mostly tight and won't tighten much more, i.e., when the culprit is clearly the CS mechanism.
The two obvious culprits were the CS mechanism (the tightening rachet that clicks, which most of us don't think works all that well) and obstruction in the harness strap path behind the seat.
I'm pretty sure the problem is obstruction in the harness path. It's hard to say for sure, since it's hard to replicate when the seat is out of the car.
Here's what I think is going on (at least on my seats): the thing you tug on is a single strap that goes under the seat and up. It's joined to the shoulder straps by a "harness yoke", a kind of metal clip. It passes by various things, and in particular a plastic piece that the manual calls a "belt guard." I think that occasionally the yoke gets caught on the guard. When that happens, it's almost impossible to tighten, even with quite a bit of slack left.
The solution for me is to start over again: completely loosen the harness and then try to tighten again. That works because the yoke gets unstuck.
I also noticed that the chance the yoke will get hung up increases quite a bit if, when starting out loose, one shoulder strap is pulled out as much as possible and the other isn't. That makes sense, since I'm pretty sure the yoke is getting caught on one side of the guard or the other.
None of this applies, obviously, if the harness is mostly tight and won't tighten much more, i.e., when the culprit is clearly the CS mechanism.
