HES Rebuilders Question

[Erik B]

I decided rather than replace a crusty old HES with another stock one that will fail in another 60k, I'd fix the problem correctly, with high temp teflon wiring. I used 19 strand, teflon jacketed, 22 AWG wire. My question is, to anyone who has made similar modifications/alterations, what do you do about shielding? I couldn't get the old wire out of the original jacket so I had to cut it off. I put the bare wire along side of all my new wires, twisted them all together, and covered them all with heat shrink. I put it back in the bike and it starts, idles, and revs OK. I just haven't put it completely back toghther and test ridden it. The bare shield is on pin one where it should be, but there isn't any foil around the wire bundle anymore. I think I'll be ok, I just wanted to see if anyone had any experience (good or bad) with the shielding on this repair. Thanks, Erik

[DonW]

I did a conversion like this on my airhead (added a second hall sensor as a "ride-along spare" in the ignition can). With normal wires, and probably a hotter environment, it has performed flawlessly for 3-4 years.

[smiller]

I decided rather than replace a crusty old HES with another stock one that will fail in another 60k, I'd fix the problem correctly, with high temp teflon wiring.

Good move. I also don't like to replace a part with a known weakness with another part with the same known weakness.

 

Re: the shielding, I have always been able to pull the new wires through the old shielded sheath but sometimes that doesn't work out I guess. Just running the bare wire along the bundle won't do much by itself but you'll still probably be OK, electrically shielding the wires is good practice so Bosch does it but it's basically a crap shoot as to whether it really matters in a given application. You can always try it and see... if you have no problems then don't worry about it.

 

 

[Andrew B]

I don't know how thick the original wire is, but you could use the outer sleeve and sheathing from some good quality cable TV coax. Do this by slipping out the white "inner" part and thread your new pickup wires thru the sheathing.

 

The idea of the shielding is to reduce the amount of electrical noise induced into the pickup cables, needless to say the new outer shielding should be grounded.

[Erik B]

Yeah, I had heard that you could pull the old wire out; maybe that's a slightly different type than mine. I noticed (in some pictures from a write up in another thread), that each sensor pigtail went up opposite sides of the HES backing plate and joined at the top. Mine's different than that. Point being, maybe there are different ones. There was no way I could get the wires out of the black jacket on mine. I even tried just pulling the bare wire and couldn't. Anyway, I understand that the shield is for noise elimination. I'm just curious if anyone has had any problems with noise, or if there's a fix i.e. aluminum or copper foil around the bundle then grounded to pin 1.

[JonathanE]

Andrew's idea above isn't bad, but I'd use a teflon insulated cable instead of a vinyl RG59 TV coax. Go to an electronic supply house and buy a teflon jacketed multiconductor shielded cable and strip out the inner conductors, or better yet, use two of them and ground the shield drain wire at one end only.

[Andrew B]

Not a bad idea Jonathan, over here in the UK since 2004 PTFE fireproof cables are used in new/reworked public buildings, this regulation includes power and alarm signal cables.

[BFG]

I got the shielded cable from an aircraft repair shop near my local airport. The owner told me they use this wire on aircraft because it is less toxic in a fire.

[NoHeat]

If you want to shield some wires, you can put them in what's called conducting "braided sleeving". Here's what I found , in the inventory of Newark, which is a big electronics supplier

 

 

This stuff is actually a tube made of woven metal wires. You squeeze it and it becomes round so that you can pass wires through it.

 

If you can make your own by tearing the guts out of some TV coax cable, as Andrew suggests, that would work just as well and cost less.

 

In any case, be sure to ground at least one end of the shield -- you can do this several different ways, including soldering it to a lug and putting the lug under a handy screw somewhere.

 

I haven't ever done this on a bike, but I've done it plenty of times in a lab.

[AndyS]

Don't you think you guys are going WAY over the top?

The HES assy fitted to the 1150 seems to work just fine (in terms of the wiring not deteriorating - although I have had the actual HES fail),

So why go to all this hassle?

Andy

[smiller]

Don't you think you guys are going WAY over the top?

The HES assy fitted to the 1150 seems to work just fine

I may be missing something but I thought we were talking about the 1100(?)

 

 

[AndyS]

Yes we are talking of the 1100 AND the 1150.

Surely once we have replaced the cables with a good quality heat resistant silicone insulation, there is no need to go with all the screening and aircraft grade materials, and 'draining' (grounding) the braid to chassis.

The connectors after all don't have provision for screening, so why go overboard?

 

Andy

[smiller]

Yes we are talking of the 1100 AND the 1150.

Well I guess we are now...

 

Regarding shielding, the OEM manufacturer does it and it is a good practice. As I said earlier it may or may not really matter in this application but some just want to do it because it is, well, a good practice. And shielding the harness can be effective even if the end connectors aren't.

[NoHeat]

Don't you think you guys are going WAY over the top?

The HES assy fitted to the 1150 seems to work just fine (in terms of the wiring not deteriorating - although I have had the actual HES fail),

So why go to all this hassle?

Andy

 

Since you addressed your comment to me, I'll reply. The OP's profile says that he has a 1100. I understand that it's the 1100 models that have the defective hall-effect sensor wiring, not the 1150. I was offering a small suggestion for the OP, as a useful alternative for him to consider if it pleased him, in repairing his 1100. He specifically asked about how to shield wires, and I was one of several posters who suggested a possible solution for doing exactly that. If that is "WAY over the top" and a "hassle", then I apologize for having troubled you.

 

Unless I missed it, nobody mentioned an 1150 until you did, anyway.