After a couple of months of winter riding, i am now sick of freezing hands so invested in a pair of BMW heated grips from Motoworks. They turned up with no instructions and no switch or control (very poor given the £160+ price tag for the pair!). I was therefore wondering if anyone had any simple instructions on how to install the grips and whether there was some existing switch on the bike for the grips that i have not noticed. Looking at other related posts, Im concerned that installation involves taking an angle grinder tot he bard etc. is this the case? I have weighted ends on my K100RT. Any help much appreciated.

When I wanted to paint the bars on my RT I ordered used ones from Motorworks which I intended to recoat and then install. They were in such good condition with one little mark I decided it fit them...but they came off a K with heated grips. The ends are different, mine has bar ends and no heated grips. The ones for the heated grips have a cut out and chances are your existing bars don't have the cut out.

On the plus side I believe the loom is already in place and all you do is plug them into the connector. There should be a switch with them ?? for installing in place of one of the blanks at the impact pad where the ignition is? The Motorworks picture for the heated grip sets shows the switch for the impact pad and also the wiring in the photo of the parts.

On the portal page of the forum there is access to interactive wiring diagrams which should help.

You will need tank off and probably loosen off the impact pad with the ignition in it. I find it helps a lot to take off the screen and the cross panel under it when accessing those areas, all held on by the 8 screen screws.

I didn't buy the set but the individual grips for weighted bars. They did not come with a switch or instructions which has left me slightly confused as to how to control them. I  don't fancy riding around with them permanently on in summer as the RT is hot enough in summer without that! Ill have a dig around this weekend and see if i can make sense of it.

There should be a centre-off rocker switch in the central pad with a 'heater' icon on it. One position is low and the other is high. There's a two-pin plug under the tank (green/black and brown) that it connects to. The rocker switch should also have flying leads off it to connect to the grips. The leads on the grips go through the handlebars and out through a hole in the centre. The reason for the exorbitant price is that over time the wires chaff through and render the grips useless. They are repairable but most people didn't know how to do this and just threw them away.

You don't necessarily need BMW heated grips. I have a pair of Oxford Hotgrips on LFB; the control box is mounted on the handlebars and of course (depending on the control unit you have), the heat settings are infinately variable from off to full. They are also less that half the price of the BMW ones (c. £54.00 depending who you go to). Motorworks will take the grips back if you want to go this route. The only mod that you will need to do is to change the plug in the BMW loom to one that will fit the Hotgrips loom. Actually, you'll need to chop both off and fit a matching plug/socket or a pair of bullet connectors.

I have just ripped the cables out of my handlebars that supplied the power for heated grips, I would hate to try and put the cables back in there.

rob_gordon wrote:I didn't buy the set but the individual grips for weighted bars. They did not come with a switch or instructions which has left me slightly confused as to how to control them. I  don't fancy riding around with them permanently on in summer as the RT is hot enough in summer without that! Ill have a dig around this weekend and see if i can make sense of it.

I looked it up on Motorworks and see the set includes everything needed, switch etc. But they also sell just the grips. The switch to control them is in the set.

Dai's suggestion is a good one.

I don't like cold hands either - and swear by heated grips in winter.

Like Olaf, I also had a quick look on the motorworks site - bizarrely the heated grip set (which includes everything apart from perhaps the slotted handlebar end fitting for attaching the bar end weights) is cheaper than buying just the throttle and clutch side heated grips!

You will probably find that you don't have the rocker switch on the dash pad - you certainly need that to be able to select low/high/off.

Like Dai, when my heated grips on my LTs decided that 25+ years was the limit of their life (I had repaired at least one of them reasonably successfully before), I saw the price of the OEM ones and opted for the Oxford Heated Grips instead. In my opinion, they are far superior and have a choice of heat settings 0/25/50/75/100% through the handlebar mounted control. 75% is too hot even on a sub zero morning! I bought 2 sets of Oxford Premium Adventure Heated Grips (OF690) (one set for each bike) from eBay last June (UK supplier) for £98 with free P&P.

The only thing I don't like about the Oxford grips is the way the wire routes externally to the bars from the inside end of the grips - not very pretty and takes a bit of fiddling to get it set (before you glue it in place) so that the exiting wire does not get in the way of the clutch or (worse) impedes full throttle operation. The OEM grips routes the (much thinner) wire from the outside end of the grips through the centre of the handle bars (hence why you need the bar end weight insert with the cut out) and out through a small hole at the middle of the handle bars, beneath the dash pad. As BobT says, I wouldn't fancy trying to thread the new wire down through the bars and out of the tiny hole - you will definitely need to push some stiff wire or thick fishing line up through the tiny hole and out of the end of the bars so that you can tie it onto the heated grip wire and pull it back through.

If I where you I'd try and return the grips you've got and either buy the set or (if you can get your money back) go and by a set of Oxford grips.

Good luck

It pains me to state this, but my honest opinion is that you'd be miles ahead if you sold the OEM grips and bought a set of Oxford Heaterz. they are far superior in design, performance and materials that what BMW sells.  
There.  Let the chips fall where they may.

I installed a set of Oxford heated grips and removed the OEM and they are a such a big improvement over the OEM, there is just no comparison.

After much deliberation and reading all your comments, I decided to abort the heated grips idea as fitting the OEM ones I bought just seemed like to much effort and cost. I would have had to fit new bars or doctor the bars I have and fit a toggle switch. If Im honest, my DIY bike mechanic skills are not really up to it.  I also spoke to the guys at motorworks and they agreed that it was too much grief to fit OEM heated grips on my bike. They accepted the heated grips back with a full refund  

Thanks for all the help and comments. I will now take stock and decide whether to go for the Oxford Grips instead.

This post may be a little off topic from what rob_gordon originally asked but I'm curious.

Has anybody done away with the intermediate harness section that contains the resistance to drop the volts for low heat and connected the grips via a DPDT (double pole double throw) relay so that the grips are connected in series for Lo and in parallel for Hi?

The last time I played with OEM heated grips I think I measured (or calculated - can't remember which) about 8 volts across each grip on low so the series value would be a bit lower but might still be OK.

Cheers

On the new download site there is a wiring schematic for heated grips.  

1.2Megohms on low?!?  How does any power get to the grips?

Where are these resistors located?  I can't recall seeing them on any of my bricks.  Was the wiring different on the '94 models?

Point-Seven-five wrote:1.2Megohms on low?!?  How does any power get to the grips?

This is the schematic for the Aussies. It's supposed to take the heat away from the handle bars.  
I think 1.2K would be more appropriate.

They're both probably a piece of constantan cut to the right length and crimped in with a brass ferrule. You can't solder constantan.

Crazy Frog wrote:

Point-Seven-five wrote:1.2Megohms on low?!?  How does any power get to the grips?

This is the schematic for the Aussies. It's supposed to take the heat away from the handle bars.  
I think 1.2K would be more appropriate.

Looked at our weather map just now and fair enough. Then panned to Au.

I think there might be a market in AU for chilled grips rather than heated grips.

Would reverse polarity work.....?

92KK 84WW Olaf wrote:

Crazy Frog wrote:

Point-Seven-five wrote:1.2Megohms on low?!?  How does any power get to the grips?

This is the schematic for the Aussies. It's supposed to take the heat away from the handle bars.  
I think 1.2K would be more appropriate.

Looked at our weather map just now and fair enough. Then panned to Au.

I think there might be a market in AU for chilled grips rather than heated grips.

Would reverse polarity work.....?

Just fit them on upside down and they will cool rather than heat.

BobT wrote:

92KK 84WW Olaf wrote:I think there might be a market in AU for chilled grips rather than heated grips.
Would reverse polarity work.....?

Just fit them on upside down and they will cool rather than heat.

 Reversed engineering!
Would it be possible to get a quick disconnect for the handle bars in order to store them in the freezer at night?

I can't recall seeing resistors anywhere in the wiring for my grips.  I vaguely recall the resistance of each grip to be something like 9 ohms, 4.5 ohms in parallel.  That would work out to about 15 watts per grip at full power which IMO is a pretty reasonable number. 

As far as a resistor for the low setting, I have no idea of where it would be hidden.  At half power to the grips it would have to be about 5 ohms and rated for about 10watts.  At that power rating, it is not going to be easy to hide, especially since it needs to be in a spot that allows it to dissipate that heat.

Iinstead of resistors, I have heard it said that the high/low power settings on the grips is done by switching from the grips in series for low to parallel for high.  That probably makes the most sense, but I have not had the occasion to trace the wiring to see if that is actually how they are wired.

Personally, I have not been able to discern a difference between high and low heat settings on my 1994 K75's which have factory grip heaters.  This is borne out by the schematic in the Clymer manual which shows the grips wired in parallel and where the heated grip switch has no ability to select a high or low power. 

Speaking of schematics, it seems odd that the load shed relay doesn't disconnect the grips when starting.  Maybe a 3.5A load isn't significant in the scheme of things. 

Another thing I learned the hard way about heated grips is that a short in the grips will blow fuse F1 which kills the battery charging circuit.  This is not a good thing if it happens at night.  Make sure you have spare fuses if you run the grip heaters.  The wire on the right side grip is especially vulnerable because of the twisting action of the throttle.

There is a resistance wire inside the harness for the grips for the low setting and it does on occasions melt and I have heard of them catching fire. I cant be real sure but those resistance wires are usually pink. I would strongly recommend a pulse width modulator for them. Connecting them in series usually wont produce very much heat as I believe that around 8 volts is needed for the low setting to be effective.

Hi point-seven-five, I think Dai is pretty close to the mark with his comment about constantan.

The resistance to create a voltage drop for Lo heat is the material that the orange wire in the intermediate harness is made of. I have posted a photo below of the wiring diagram that I sourced from this forum many moons ago and pasted into the back of my manual. I've added notes over time as I have repaired grips on my bikes. The key information is the note that identifies the orange wire material as 6 ohms per metre. The intermediate harness orange wire is roughly 300mm long and I measured the resistance at about 2.2 ohms. The connection diagram that CF posted earlier in this thread does not show this info.



I recently saw a post from Duck on the Adv Forum describing the problem that I currently have on my K75 grips. I had a short in the intermediate harness caused by the heat from the orange wire melting insulation when I was running on low heat for an extended period of time. I believe I caused the problem myself by using self fusing tape to rewrap the second hand harness which had all its original cloth tape falling off. The self fusing tape sealed the harness very effectively, not allowing the heat to escape. Light bulb moment, Ah! that's why the factory use cloth gauze tape on that section of harness. Luckily my fuse blow caused by this happened in daylight.

Link to Duck's Adv Forum post.

I will experiment with the series/parallel connection that I asked about while repairing mine and am giving consideration to the PWM solution used by Rick G and described by Duck.

I know this is a bit of a ramble but some members may not know about that intermediate harness in the OEM grip circuits - hope it helps someone.

BTW thanks for all the suggestions about cooling grips for us down under. We sure could use it - as I type this it is 43 deg C in the shade outside just after lunch, heading for a predicted 46 - 47 deg C (116 deg F).

Cheers

OK!  Now I get it.  The 2.2 ohms cuts the power roughly in half to about 9 watts per grip.  It also explains why I never saw a resistor. 

I guess the designers figured that the power dissipated by the wire would not be a problem since the heaters would only be used when the temperatures are lower and the cooling better.

I must have come across the only K1100LT without factory heated grips. At that point I didn't have enough parts in stock to fit a genuine set (I do now) so fitted a set of £10 cheapo jobs bought off eBay. I wired them through a genuine BMW H/G switch assembly and they work just as well as my other BM's that have the genuine article fitted.
I don't expect them to last forever so when they give up I'll raid my parts bin...or maybe not!

I got a set of them a few weeks ago. I am going to make a set of foot warmers from them and put them in my boots for the alpine rally this year.

RicK G wrote:I got a set of them a few weeks ago. I am going to make a set of foot warmers from them and put them in my boots for the alpine rally this year.

Brilliant!

While we're on the subject of OE heated grips, is it normal for them to stop heating if the engine is ticking over or you're just bumbling around town? I always thought there must be something controlling the grips to look after the battery or something but the wiring diagram put up by CF makes them look very straight forward.

Gaz wrote:I have posted a photo below of the wiring diagram that I sourced from this forum many moons ago and pasted into the back of my manual.

It's on the download page.
The new Website/Download page has almost all the subjects of the old one.

Thanks CF, I finally got around to looking at the new downloads page.

Had a proper look at the connection diagram that you posted in post 12 of this thread and it is quite different from the one that I used. I wondered where point-seven-five had come up with the 1.2M ohms comment and now I see that it is off that diagram. Is that diagram from a different model as the colours of wires at the switch and resistance value/s are different between the two schematics in the downloads section. If they are different for different models maybe some members with the appropriate knowledge can advise and we could have the titles of the schematics adjusted.

Sorry to be picky but it's no use having info in the downloads if it is not correct.

Cheers

Gaz wrote:Sorry to be picky but it's no use having info in the downloads if it is not correct.

I will rectify the error or remove the schematic.
People have to tell me when they find a problem or mistake. I cannot do everything on my own.

No reflection on you CF. My knowledge is not broad enough to know whether or not the second drawing is valid for other models to the ones I have worked on, hence the question I posed to other members who are more knowledgeable.

I very much appreciate every thing you do for us.

Cheers