'81 R100T Fuse ???'s

[awshucks]

My Clymers says they are under the seat but can't find them there or behind the two side covers. Under the tank? I lost my turn signals and brake light at the same time, bulbs are good. Are the turn signals and brake light fused together?

Also can't seem to find a wiring diagram in the Clymers that covers this bike. Would like to know if there's a model in yours that's the same as this model?

Thanks!














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[TGHSMITH]

the spares might be under the seat in the tool kit... the operationals are in the headlight bucket hiding behind all those wires..

 

[rlaird]

Mine are in the headlight shell

 

[TGHSMITH]

make sure the master plug for the rear harness isn't loose, it's around the area of the tool box and battery.....

 

[awshucks]

thanks, just got the fairing on,

 

[AnnapolisAirhead]

My Clymers says they are under the seat but can't find them there or behind the two side covers. Under the tank? I lost my turn signals and brake light at the same time, bulbs are good. Are the turn signals and brake light fused together?

Also can't seem to find a wiring diagram in the Clymers that covers this bike. Would like to know if there's a model in yours that's the same as this model?

I may be way off base here, but the Clymer's wiring diagram for your bike I believe is on page 782 if you have a fairly recent version of the manual (the one with the silver R75/5 on the front, missing its tank knee pads).

While it does not explicitly list R100T, I'm betting its the same. What's your VIN on the bike? Mine is a 1983 R100 according to the badges, but when I look up the VIN, it comes back an R100T. It's a US bike.

Inside the headlight shell, furthest from your reach is a circuit board. At the top of that board there are two fuses, one 20amp, one 10amp. Neither of which have anything to do with turn signals or brake lights, according to the Clymer's and Haynes wiring diagrams. Sounds like it could possibly be a ground issue or like someone else posted the wiring harness connector at the subframe near the battery. Here's a picture of a circuit board without all the wiring attached to get your bearings (hard to see numbers on that board and Clymer's doesn't list them for some reason).

 

[RecycledRS]

I believe the fuses in in your picture should both be 8amps each unless I'm missing something.

 

[83014]

I lost my brake light on my 81 R100RT. It was a fuse in the headlight shell. Inspect your fuses and replace if necessary. It worked for me.

 

[AnnapolisAirhead]

Good point RecycledRS. The PO moved these fuses outside of the headlight to external holders. they are 20amp and 10amp in my case. I think that is stock, but I could be off.

I've never seen any documentation in Clymer's or the Haynes manual as to what size fuses they are. Who else has 8amp fuses in both slots? It'd be nice to know for certain, although my bike functions fine.

 

[Bill Burke]

Ceramic fuses are color coded depending upon amperage. The two fuses shown in the picture above are 8 amp, which is correct on BMW's. For color coding reference, see this:

http://www.car-fuses.co.uk/files/subcat.php?cat_id=51

 

[AnnapolisAirhead]

Ceramic fuses are color coded depending upon amperage. The two fuses shown in the picture above are 8 amp, which is correct on BMW's. For color coding reference, see this:

http://www.car-fuses.co.uk/files/subcat.php?cat_id=51

Good to know Bill, thanks. So my PO had about a half a bazillion mods in the headlight bucket (CB radio, AM/FM/Cassette, moved fuses externally, vetter harness, etc.). I've removed everything and put it back to stock (except left the fuses outside). The fuses were changed to a 10 and 20 amp, glass barrel types in sealed fuse holders. Those will pop right into my fairing. The bikes is also dual plugged and has a Dyna ignition boosters to boot (factory electronic ignition). So, now I'm really wondering why the increase in amperage and what I may be exposing. .

With respect to this thread, if his horn works, that covers one fuses. If the bike starts, that covers the other. So the issue would be elsewhere IMO.

 

[Yarddog]

I may be doin' the same thang as AA, however, I will use the modern ATC (?) fuses that are plastic with spade terminals...I agree that they are waaaayyyy too inconvenient inside of that headlight shell...with or without fairing...and not to wear out this subject, because I KNOW that there must be those who get chafed when I mention this, but here's another example of...yep...shaky engineering!!! I like the idea of a central terminal block, but WHY inside the headlight shell? Harleys have 'em under the seat...much more convenient...

 

[AnnapolisAirhead]

I'm thinking its more along the lines of a dry place to put the fuses, since these bikes get used in all conditions. Most (not all) Harley's are fair weather bikes, even if their riders aren't.

The RS and RT fairings have a good place for them on the dash, front and center so that's where mine are now. The PO had made a nice bracket that tucked neatly onto the voltage regulator mount.

 

[CTellman]

My fuses . . . ..

Not sure if this is relevant but my fuses are located at the very end of the "backbone" over the battery. The fuse holder has three or four receivers and they are american style fuses. There is a weatherproof cover that swings horizontally.
I hope this helps.
Campbell Tellman II
'93 R100RT

 

[AnnapolisAirhead]

Not sure if this is relevant but my fuses are located at the very end of the "backbone" over the battery. The fuse holder has three or four receivers and they are american style fuses. There is a weatherproof cover that swings horizontally.

I wonder, did they change to that style of fuse in the later years of Airheads? Would love to see a picture of you have one.

 

[PGlaves]

I wonder, did they change to that style of fuse in the later years of Airheads? Would love to see a picture of you have one.

Yes - they relocated the fuses sometime in the early 80s. I'm not positive when. Voni's '83 R80ST and my R80G/S both had mini fuse boxes located right ahead of the seat, right at the back end of the frame backbone. Small black box with a silver knob to remove the cover.

I haven't played much with a later RT or RS Airhead, but doubt even BMW would hide fuses at a location where taking off a fairing would be required. When I had a /5 with Leuftmeister fairing I relocated the fuses because removing the fairing in a motel parking lot in the rain was only going to happen once, not twice.

 

[AnnapolisAirhead]

I haven't played much with a later RT or RS Airhead, but doubt even BMW would hide fuses at a location where taking off a fairing would be required. When I had a /5 with Leuftmeister fairing I relocated the fuses because removing the fairing in a motel parking lot in the rain was only going to happen once, not twice.

Well, it's inconvenient on an RT/RS, but you need not remove the fairing, just the front lens by backing out (not removing) four screw under the rubber lip, then a squat Phillips head to easy the headlight ring. Still, under the seat or on the dash is mucho easier.

Fairing removal in a parking lot? yikes. I saw the pictures of you working on Ara's GS when he needed a hand...I only wish I had the confidence to tear into any bike, anywhere. Between you and Voni, you've been through about every scenario of on the road repair that I could ever imagine. Best to put the PGlaves number on speed dial before heading out on a long one.

 

[lkchris]

Yes - they relocated the fuses sometime in the early 80s. I'm not positive when.

For the "big bikes," it was with the 1985 models. This being only R80 and R65, of course, the R100s not returning until 1987. Those with the "K-bike" suspensions.

Other poster's "shakey engineering" notion is off base.

First of all, it's a "cultural" thing, and unlike the USA's "model T" culture there is nearly zero incentive in German automotive culture to design for DIY servicing.

On my '84 RS, I believe I've had one fuse failure in 25 years, and that frankly could have been on my previous '78, as it was a long time ago. It's not really a DIY nightmare, then, and thinking so is overreaction if not just ego run amok. And "mov-a-fuse" solutions are indeed solutions looking for a problem.

My Mercedes friends all insist, BTW, that the ceramic fuses ought to be replaced every maybe 10 years in any event, as they're purportedly subject to just age fatigue. Guess I will.

 

[Yarddog]

Other poster's "shakey engineering" notion is off base.

First of all, it's a "cultural" thing, and unlike the USA's "model T" culture there is nearly zero incentive in German automotive culture to design for DIY servicing.
.

Copy that, my friend...however, unlike most all y'alls, I own and work on...both... and I built my Harley from the ground up...so, I think I know of where I speak... When it's a hassle to service such simple things as the oil filter, air filter, and fuses, when doin' so could be so easy and quick, I tend to draw comparisons to the American product...oil filter? Spin it off, spin it on, no interference with the frame or exhaust, easily done on a hot machine, no need for a 'hinged filter'!!! Omigod! A hinged filter!!!

Air filter? One bolt takes off the cover, three screws takes off the filter...all out there in the open...no need to try to line up bolts, a hold down clamp (a clamp?) then line up that lonnnnnng screw thru a hole!!!

Fuses? What fuses? We use...circuit breakers! The terminal board is located just under the seat...easy and quick...

Paintin' em black? The MoCo has been doin' it for years...no problemo...

Naw, I just poke a little fun here and there, and just kinda mock some of the high handed 'sniffy' attitude that I see here and there with regard to the 'superior' engineering of these bikes...My Beemer and my Harley are two different styles of ridin' and wrenchin', and when I make reference to 'vaunted Teutonic engineering', it's all in good fun...kinda...

I knew someone would comment on it, but lemme tellya when you own both, you come to appreciate the strengths of both of 'em...and I've been riding 40 years, owning Harleys for 35, and I could give one rip less about lifestyle!!!!

I'm following this thread religiously, as it's basically what I'm doin' to mine right now, so I didn't wanna hijack it or cause too much raise in blood pressure!!!

 

[awshucks]

Here's what happened. I'm finishing the conversion from a 'T' to an 'S'. My one mechanic buddy wired the two gauges, colck and volt meter w/ a harness that only needs 3 wires, keyed hot for volt and gauge lights, constant hot for clock and common ground.

Had problems w/ the quick disconnect plug and a second buddy, 'Metric Dan' who works in a local bike shop and provided the quick disconnect plugs had switched the ground and keyed hot wires.

I obviously fried something, everything except brake lights and turn signals work fine. My tail light has two bulbs, one for licence plate down lower and a twin element 1157 type up above/ only the licence plate one comes on.

I was hoping to get by w/ just a fuse or two, but am not a lucky type. So far, I can only find one fuse behind the wire mess in headlight shell and it's a lot lower down than the pic provided in previous post [thanks for that, btw]. It's a whiteish ceramic and going by a visual on the element, probably 8a.

I've scoured the battery area and behind the tank and can't find any more there, guess pulling the tank is next.

Thanks for your help.