Tach Lights Out

KingBear

Hooligan
Over a year ago I decided to upgrade to LED instrument lights - idiot panel lights, speedo and tach. After a few missteps ordering the wrong stuff I got it worked out and everything was working fine, but then the two lights on the tach went out. I was annoyed but didn't bother to get back into it until this past weekend when I was switching out my turn signals. I went into the tach and checked the bulbs, fuse, and harness connection - all good. The bulbs work fine in the speedo socket, the fuse is fine and everything else on that circuit works, and the harness is securely plugged, again with everything else on that connection is working fine. Help me out here, guys. Why wouldn't both of my tach lights be working?

I know I'm an idiot, but changing a light bulb? Really!

:hung:
 

Lone Trumpet

Street Tracker
I'd be suspect of the factory wiring. I say that because I had the same problem on my '06. It was determined (by my dealer) to be the wiring sub-harness (to gauge lights) that was bad. Luckily it was just before warranty expired and the dealer replaced it... no such problems since.
 
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KingBear

Hooligan
Okay, with that in mind I purchased a multimeter on my way home from work last night. Hopefully I will be able touse it to determine whether current is flowing as far as the sub-harness. If I find that juice is flowing that far but not reaching the light sockets I will identify the relevant wires, cut them and install simple bullet connectors thereby bypassing the harness altogether.

Now all I have to do is learn how to use the multimeter. Hello YouTube. :wave:
 

KingBear

Hooligan
Lone Trumpet, I tried using the multimeter with little success, but your diagnosis of the sub-harness coincided with another I got at the other site, plus my own instincts despite not being sure about my reading of the schematics and my reluctance to "dig in" without being sure where to start or what to look for.

Sure enough the sub-harness wiring was broken at the splice of the speedo and tach lighting, and green with corrosion. The speedo wiring was also broken, probably hanging by a thread until I started pulling things apart when it finally separated completely. The splice is now repaired and I have instrument illumination once again, a nice red glow supplied by SuperBright LEDs.

Thanks for the help. :cheers:
 

fernandos1

Scooter
Lone Trumpet, I tried using the multimeter with little success, but your diagnosis of the sub-harness coincided with another I got at the other site, plus my own instincts despite not being sure about my reading of the schematics and my reluctance to "dig in" without being sure where to start or what to look for.

Sure enough the sub-harness wiring was broken at the splice of the speedo and tach lighting, and green with corrosion. The speedo wiring was also broken, probably hanging by a thread until I started pulling things apart when it finally separated completely. The splice is now repaired and I have instrument illumination once again, a nice red glow supplied by SuperBright LEDs.

Thanks for the help. :cheers:
Hi, can you please tell me which LED model(s) you got? I want to do the speedo, Tech and idiot lights. I know that they sell the kits but it seems that it's twice as much as buying them individually from Superbright.

Thanks
 

KingBear

Hooligan
Hi, can you please tell me which LED model(s) you got? I want to do the speedo, Tech and idiot lights. I know that they sell the kits but it seems that it's twice as much as buying them individually from Superbright.

Thanks
No problem, let me look back through my records and I will get back to you. It's easy to get confused with all the lights they offer, I messed up my first order but finally got it worked out.
 

Lone Trumpet

Street Tracker
Hi, can you please tell me which LED model(s) you got? I want to do the speedo, Tech and idiot lights. I know that they sell the kits but it seems that it's twice as much as buying them individually from Superbright.

Thanks
If you have a newer EFI Bonnie I think the lights may be different (than KingBear's carbed Bonnie). Not sure about that, but might be worth verifying the lights are the same if yours is EFI.
 

fernandos1

Scooter
I hate to waste money but it seems that in this case, one is paying $10-$12 for New Bonneville's homework in figuring out which bulb is being used. I asked the dealer and he had no idea. He looked at the Triumph's parts diagram which doesn't specify a bulb size.
 
The idiot lights are the 74 series. Problem is that you can't get a non-polarized 74-size LED for the turn signal, so you have to "modify" a larger-base bulb such as a SuperbrightLEDs WLEDx6.

The older clocks can use SuperbrightLEDs. Speedo uses one WLEDx5 and one 74xHP or 74xHP3. Tacho uses two WLEDx5. There are other options to try, but these worked for me.

Here's the SuperbrightLEDs link for more information:

http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fmini-wedge.html
 

Brylcreem

Scooter
I changed my speedo and tach over to blue led bulbs yesterday after the top bulb died in my speedo,
got them from squaredeals uk £9.99 plus post.
Hope I don’t have any of these problems.
2005 bonneville Goodwood Green.
 

rbirkey

NBRAdmin
Staff member
NewBonneville carries LED instrument replacement kits for Bonneville / Thruxton / America / Speedmaster.


 
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