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Discussion Starter #1
The dials on my tl dim down alot when I press either brake, they will brighten when the bike is revved what could this be a sign of?
 

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Weak battery. Poor reg/rec unit. Bad earth. Short in the brake light circuit.

I'd start by putting a meter across the battery to check your charging voltages.
 

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Discussion Starter #4
So I charged the battery last night and popped it in this morning but the same thing happened. After pressing the brakes a few times I blew the brake bulbs. The tails are still working just both brakes blew, they are new bulbs I only put in 2 days ago
 

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Sounds like a wiring fault. In order to blow both bulbs like that they must be receiving excessive voltage. This assumes they have blown and its not just a failure in the circuit for those filaments.

There's only two ways I can think of picking up a voltage excess. One is the R/R is faulty but if this were the case it should be affecting everything. The other is a short between one of the wires in the brake circuit and the generator output lines.

The other thing is a bad connection. When the brake light circuit is closed the bad connection causes what is effectively very rapid switching. Filament lamps don't like being switched on and off quickly. Try it yourself on a regular incandescent light fitting if you want to see this. If you just turn it on and off as fast as you can you can probably blow the bulb in about 10s.

Get a meter onto one of the bulb sockets to see what voltage is being supplied. That should give you an idea of the type of fault to look for.
 

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There's a Shindengen that some people use. Check the voltages on your existing system first though.
 

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Discussion Starter #9
Put the multimeter on it and it's reading 13.6v at tick over and when revved it drops to 12.9v
How does that sound?
 

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13.6V isn't great but its acceptable. Now what happens when you hit the brake lever?
 

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Discussion Starter #11
It stays the same when the brakes are pressed but maybe that's because the brake bulbs blew the other night. When I revved it dropped to 12.9v is that normal
 

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Yes. 12.9 is getting a little on the low side tho'.

Next test is to measure the voltage at the brake light connector. Need to see why the lamps are blowing.
 

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..... When I revved it dropped to 12.9v is that normal
Yes. 12.9 is getting a little on the low side tho'.

.....

Yes, it's normal for a tired old TL charging system that needs to be fixed.

When it is revved (4K ~ 5K rpm), the voltage should be around 14 volts.

When you find the reason the bulbs are blowing, you have another project waiting for you. :)
 

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Discussion Starter #14
Just checked there now the brake light reads 12.6 and then 10.6 when the brakes are pressed?
The tail lights are still working but seem very bright. They are reading 12.8v
 

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That's an excessive drop for a couple of brake lamps. I suspect you have a short from the R/R output into the brake light rails.

Your charging current is being diverted into the brake lights.

At this point I'll defer to Six5 with his encyclopedic knowledge of the wiring system to give you a likely location to search.
 

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Ok thanks mate. Does the r/r from a zzr1400 fit? I think I read somewhere it does?
The unit snowy is referring to does not "fit" directly. It is however a huge upgrade. Look up the "charge mod". Ask any questions you may have...

The cheapest option is a wiring kit and a used r/r. You'll also need an inline fuse.

I suggest the sh775ba unit. You can find them from Polaris atvs.

Something a la
http://pages.ebay.com/link/?nav=item.view&id=291403162635&alt=web

And
http://pages.ebay.com/link/?nav=item.view&id=361450787822&alt=web

It does sound like you have something causing those bulbs to burn though... need to sort that first...
 

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I'm struggling to get a clear picture of what is actually failing here, but I'll take a stab at it....

.....

Next test is to measure the voltage at the brake light connector. Need to see why the lamps are blowing.
Just checked there now the brake light reads 12.6 and then 10.6 when the brakes are pressed?
The tail lights are still working but seem very bright. They are reading 12.8v

maddie, at this point, we have already confirmed that the engine was running, so the charging system was at least functioning as best it could.

Were the tail light bulbs new, or were they still the bulbs with the burnt out brake filaments?

Even so, if the measurement was taken "at the brake light connector" as snowblind suggested, why was 12.6V present before the brake was activated? :confused There would be 12V (nominal) on the Org/Grn wire at the brake light switch, but no voltage should be on the Wht/Blk wire until the brake switch was activated.

Also, (assuming the bulbs were fully functional) the 10.6V could be explained by poor terminal connections and a tired brake light switch. As current flowed through the brake filaments, voltage drops would form across the other resistive elements in the circuit.

On top of these questions and conclusions, there is nothing lethal about 12.6V on a brake light bulb. That level is well within its limits. Did you happen to get a bad lot of bulbs? Did you accidentally grab the 6 volt counter parts?




That's an excessive drop for a couple of brake lamps. I suspect you have a short from the R/R output into the brake light rails.

Your charging current is being diverted into the brake lights.

.....
Snowblind, what is leading you to this suspicion? Even if such a short existed, the bulbs should be able to handle the 15 volts coming out of the R/R. Help me Obiwan....
:)
 
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