 Yet another electrical question - relay
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Joined: Dec 2005
Posts: 604
Adjunct
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OP
Adjunct
Joined: Dec 2005
Posts: 604 |
Electrical - a pretty "hot" topic lately.
It's my BA winter project, & I'm dug in pretty deep at the moment.
Out of my depth, maybe.
Rumor has it that relocating the horn makes for cooler oil temps.
Accordingly, I'm giving it some thought - maybe horn under the seat.
Now, the stock beeper is kinda wimpy anyway, and hiding it under the seat won't help that.
So, maybe the wiring could stand an upgrade.
This would seem to dictate use of a relay.
I inherited the relay from Biker Thug's lightbar setup, so that's a candidate.
Maybe I oughta get some comprehension of how the thing works before trying to install it.
It appears that pin 30 is +12 for switching to the target accy.
85 & 88 look to be the switch circuits.
87 is the switched terminal.
Based on this logic, I thought +12 to 85 and ground to 88 (or vice versa) should produce continuity from 30 to 87.
It doesn't.
Does pin 30 need +12 before the switch will work?
Related:
The frame has three tabs for relays/flashers.
Only two are in use in the stock harness.
The third would be a pretty slick place for an extra relay.
Does anyone know where to get one of those rubber mounts like the flasher and starter relay use?
Said Molly to James, that's a fine motorbike.
Richard Thompson
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Re: Yet another electrical question - relay
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Joined: Jan 2005
Posts: 12,877
Should be Riding
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Should be Riding
Joined: Jan 2005
Posts: 12,877 |
Did you remove your AI? And if so, save the mounting screws? That's a GREAT place for relays. I have two there.. One horn, one driving lights. Not sure about the post numbers off hand (anyone?) but the basic operation of a relay goes like this... The "hot" lead for your horn connects to one post, and then the correspoinding post goes to the battery. A lead from the switch connects to a 3rd post, and the other corresponding one goes back to ground I think.... Honestly I just took the two leads off the original horn, and connected them to those posts. Simple that way, and the wires reach that AI bracket under the tank. Basically, a relay is an electrically activated switch. Your stock horn switch activated the relay switch. Clear as mudd? If you do a search with my usernam and go back far enough, you'll find lots of info.
Benny
Black & Silver '02
Too many mods to list
Not enough miles ridden
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Re: Yet another electrical question - relay
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Joined: Jan 2005
Posts: 2,362
Oil Expert
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Oil Expert
Joined: Jan 2005
Posts: 2,362 |
Quote:
Rumor has it that relocating the horn makes for cooler oil temps.
Not really, unless you have a very large horn in the way of the oil cooler.
Quote:
Now, the stock beeper is kinda wimpy anyway, and hiding it under the seat won't help that. So, maybe the wiring could stand an upgrade. This would seem to dictate use of a relay.
Yep, yep and yep. Don't let ANYONE convince you a relay's not needed with anything bigger than the standard horn. If they weren't a good idea auto manufacturers would have stopped using them years ago. Even if they're not ABSOLUTELY necessary with your chosen device, why wouldn't you use a safety device if it was cheap and easy to fit? They're a LOT cheaper than a new wiring harness for your bike.
Quote:
I inherited the relay from Biker Thug's lightbar setup, so that's a candidate. Maybe I oughta get some comprehension of how the thing works before trying to install it.
Headlight relay will work fine. Think of a relay as just a normal (heavy duty) switch, with the toggle replaced by an electromagnet. Put a small current on the magnet, it closes the switch and carries a large one.
Quote:
Based on this logic, I thought +12 to 85 and ground to 88 (or vice versa) should produce continuity from 30 to 87.
It doesn't.
Does pin 30 need +12 before the switch will work?
No.
I've never seen a relay with a pin numbered 88... chances are you're mis-reading pin 86. Pin 30 is your supply voltage (battery positive), pin 86 is your switched voltage ("hot wire" from original horn connection), pin 85 is your earth (battery negative or any point on the frame) and pin 87 is your load (positive terminal on new horn).
If you put 12V on 86 and 0v on 85 (or vice versa) you should hear it click and you should have continuity between 30 and 87. If it doesn't, the relay's dead - go to an autoparts shop and spend $2 on a new one. While you're there buy a socket for it as well rather than trying to use crimp on terminals etc. You can get sockets with wire pigtails already in place. While you're at it get an in-line fuse holder - you can get weatherproof ones with rubber boots. Don't get clever and buy a relay with the built in fuse, or Murphy's Law will make it blow in the middle of nowhere when you can't/don't want to take off the tank to change a fuse. Put the fuse holder (10A should be fine) between the battery positive and the relay, as close as possible (neatly) to the battery. Also buy a yard or two (see? I said "yard" instead of "meter"... I can speak American!  ) of twin conductor, common sheath wire and some black cable ties to wire up your new horn so you'll have a single black cable to tie to your frame and look professional. Route the cable alongside the existing harness. If the pimply youth at the auto-parts shop doesn't know what you're talking about, tell him you want two wires inside one cable, big enough to run a horn.
Quote:
The frame has three tabs for relays/flashers. Only two are in use in the stock harness. The third would be a pretty slick place for an extra relay.Does anyone know where to get one of those rubber mounts like the flasher and starter relay use?
The third is for the driving light relay. I imagine you could get the rubber mount from your Triumph dealer, or just cable-tie it to the frame, or as Benny suggested use the AI pump's mounting point if it's unused. (Personally I have my alarm on those mounting points as well as my horn relay.)
Finally, I can thoroughly recommend the Stebel Nautilus Compact horn. Ugly as sin but D@MN loud! Make sure you get some plastic hose for the air inlet and route it someplace dirt/water free, like under the tank. Don't bother with the Chrome version, rumour has it that it flakes off in no time. They CAN be mounted in the standard position using the standard hardware by angling the mounting bracket up a bit - several members here (including myself) have done so. Because the horn sits higher than standard it doesn't interfere with airflow and is difficult to see but has nothing blocking the sound output. I bought mine from Twisted Throttle and have good things to say about their service, including warranty replacement.
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Re: Yet another electrical question - relay
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Joined: May 2007
Posts: 6,432 Likes: 1
Worn Saddle
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Worn Saddle
Joined: May 2007
Posts: 6,432 Likes: 1 |
Dang, Matt...that answer's so good I printed it to a PDF for later consumption. The Mods ought to go straight to the tech vault with this one!
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)
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Re: Yet another electrical question - relay
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Joined: Jan 2005
Posts: 2,362
Oil Expert
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Oil Expert
Joined: Jan 2005
Posts: 2,362 |
Heh.. thanks  It'd probably need some re-writing for a vault item rather than as an answer to a question... will do it when I have a few minutes free.
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Re: Yet another electrical question - relay
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Joined: Jan 2005
Posts: 1,179
Learned Hand
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Learned Hand
Joined: Jan 2005
Posts: 1,179 |
Great answer Sandman! The cooler temperature is more than a rumor though, based on Brent's uncalibrated temperature screw-in guage, I'm running at least 5 degrees cooler by placing the horn (replaced with Stebel) under the seat. I was using an aftermarket horn in the standard location, but it wasn't much larger than the stock Triumph horn.
Regards,
Tom
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Re: Yet another electrical question - relay
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Joined: Dec 2005
Posts: 604
Adjunct
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OP
Adjunct
Joined: Dec 2005
Posts: 604 |
Thanks, all.
Exactly what I needed to know.
I thought the relay should work as Matt describes.
The condition of my eyesight and the lighting in my shop probably contributed to confusion re: pin 88.
Can't get one to work on the bench, though.
Even tried a known-good starter relay, too.
No click, no continuity.
Maybe a problem with test leads or something.
The first store I went to had some nice electrical goodies, but couldn't supply the socket.
I'll come up with one from somewhere if I have to go junkin' for it.
BT's old harness has one on it, but I hate to tear it up.
Something tells me I can get a feed from the fusebox (vs. batt).
If not, I'll add a fuse & maybe a terminal block.
My harness is apart now anyway, so I'll just build the necessary wiring in.
I've ripped a lot of stuff I didn't need out of it.
This gets added back.
Stebel looks good.
Lots of options to consider there, I guess.
Yes, to the vault with you!
Thanks again.
Said Molly to James, that's a fine motorbike.
Richard Thompson
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Re: Yet another electrical question - relay
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Joined: Dec 2005
Posts: 604
Adjunct
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OP
Adjunct
Joined: Dec 2005
Posts: 604 |
That went so well I'll throw something else out - fishing for more words of wisdom.
Still on the subject of relays (mostly), so I ain't even hijacking myself.
Service manual says we have a starter relay and starter solenoid.
This would seem to indicate a reluctance to tax the starter button/wiring with the solenoid's current draw.
Wiring to the solenoid is still pretty wimpy, though.
Haynes book says we have a headlight cutout relay (starter relay) and starter relay (starter solenoid).
Anybody else confused yet?
This language would seem to indicate the (DPDT) "starter relay" is really just there to provide a headlight cutout.
My guess is the truth is some combination of both.
A secondary issue here is solenoid current draw.
Info on this seems to be pretty hard to come by.
My solenoid spent the summer hanging on the battery cables under the seat.
Not real tidy.
One option would be to make a little bracket for it like Geoff did ("Airbox replacement project", performance forum).
Another would be to switch to a wall mount solenoid.
A Ford unit comes immediately to mind, but what about current draw from that bad boy?
I ended up with a used one from a Katana.
That's an option.
Cole-Hersee & others make gobs of them too, but I don't know if they suit the purpose.
Said Molly to James, that's a fine motorbike.
Richard Thompson
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Re: Yet another electrical question - relay
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Joined: Jan 2005
Posts: 12,877
Should be Riding
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Should be Riding
Joined: Jan 2005
Posts: 12,877 |
No need for a socket for the relay. Spade connectors work just fine. Grease em good.
Benny
Black & Silver '02
Too many mods to list
Not enough miles ridden
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