Page 1 of 1

Turn signal relay killed 1984 Honda Spree

Posted: Sun Nov 05, 2017 2:50 pm
by Zachfarrell
The spree was running well, no electrical problems except the turn signals weren't operating. So, I decided to replace the turn signal relay. After connecting it to the scooter and turning on the turn signal, the turn signal flashed once and the bike went dead. Now it won't turn on, so I think there is an electrical problem. Battery is charged. Could the Relay have destroyed the electrical that fast?

Edit: Just turned out to be a blown fuse. Does anyone know the correct voltage for the turn signal relay so I don't blow another fuse?

Re: Turn signal relay killed 1984 Honda Spree

Posted: Sun Nov 05, 2017 7:32 pm
by Sharklin
I've been using this one.

https://m.ebay.com/itm/Speed-Adjustable ... 9624970006

So far no problems. I also run a 3A fuse (all i had on hand) instead of the 7A the manual calls for. Still no blown fuse.

Re: Turn signal relay killed 1984 Honda Spree

Posted: Mon Nov 06, 2017 12:24 pm
by mousewheels
A fuse blown after the flasher was replaced does not mean the new flasher is bad.

A working flasher puts virtually a dead short across it's terminals to turn the lights on.
A bad flasher cannot cause a larger current to flow. At worst, the lamps
would be always on.

It is the resistance of signal lamps that limits the current. The resulting current is about 4.1 Amps.. See calculations at the bottom of this post.


Flasher diagram:
Flasher_Schematic.png
Flasher_Schematic.png (85.7 KiB) Viewed 3402 times
Calculation of Turn signal current:
TurnSignal_Lamp_Current.JPG
TurnSignal_Lamp_Current.JPG (29.88 KiB) Viewed 3402 times

Re: Turn signal relay killed 1984 Honda Spree

Posted: Mon Nov 06, 2017 12:29 pm
by mousewheels
For troubleshooting this issue there are two main possibilities:

1) There is a fault in the turn signal circuit
-- Short circuit - mis-wire, pinched wire, worn insulation short
-- Wrong lamps

2) There are additional loads or faults on the +12v battery outside the turn signal circuit.
In this case the ~4 amp load of the flashers when turned on becomes
'the straw that breaks the camel's back'.

Some ideas:
Have accessories been added?
Has the headlamp circuit been altered to run off +12v dc instead of the stator AC coil?