MTFCA Forum

I picked up a VSM 900 turn signal switch and I'm preparing to wire it up. I'm using two tail lights, each converted to two filaments, and a brake pressure switch (I installed the hydraulic disc brake kit).

My questions are these:

1. What amp fuse should I use for the wire from the battery into the X terminal of the flasher?

2. The grey with black tracer goes to the brake switch. Does it matter which terminal? Am I supposed to run switched battery power to the other side of the brake switch? Or nothing, as shown in the diagram?

3. Is this diagram telling me to wire the tail lights together? I assumed the tail lights would be wired independently of this switch, but now I'm not so sure.

I stink at automotive electric. Thanks for the help.

I recently installed one of these. The fuse came with the kit. I don't recall the amperage but I can check for you if you didn't get a fuse.

I had already installed a brake switch. I connected the output wire. The diagram for taillights is confusing by because the wire shown does not show a correct wire scheme. I wired taillights from the main switch.

Mark Nunn wrote: ↑

Fri Jul 09, 2021 9:02 pm

I recently installed one of these. The fuse came with the kit. I don't recall the amperage but I can check for you if you didn't get a fuse.

I had already installed a brake switch. I connected the output wire. The diagram for taillights is confusing by because the wire shown does not show a correct wire scheme. I wired taillights from the main switch.

Mine came with the fuse holder for one of those tubular glass fuses, but I'm going to put in the blade type.

I think you're right, just wire the tail lights independently as normal, and run power to the other side of the brake switch.

I wanted to hear somebody else say it though because I don't trust myself.

1- power to the brake switch ‘other’ terminal. You may want to tap off a lead after the fuse

2- The tail light is missing a wire in that schematic. Just the original (usual) green wire/green tracer wire tied anywhere on the two lamp filaments shown tied together.

Copied another schematic for similar turn signal. Wire colors are different but same connections
Your switch is missing the connection as noted

The fuse that came with my kit is 20 amp. That seems high to me but I installed it anyway.

FUSE Calculation
What kind of bulbs? Filament or LED? 6 or 12 volts - AMPS = watts/volts
Do the math. If there LED, 20 amps is too high because you want the fuse to blow when the expected load on the circuit is exceeded. The chart is indicating wire size as well

TRDxB2 wrote: ↑

Sat Jul 10, 2021 11:39 am

FUSE Calculation
What kind of bulbs? Filament or LED? 6 or 12 volts - AMPS = watts/volts
Do the math. If there LED, 20 amps is too high because you want the fuse to blow when the expected load on the circuit is exceeded. The chart is indicating wire size as well

Thanks!

I'll print and post this handy chart in the engineering spaces.

You mean the bulb shouldn't protect the fuse by failing first?

Hey, thanks for all the help.

Got it wired up right on the first try!

Tail lights, brake lights, and turn signals make this much more drive-able around here.

And I must say, I'm quite impressed with this VSM 900 unit. It's a substantial piece of equipment.

Now I'll see if I can't do something about the spaghetti bowl at the bottom of my steering column.