Signal and gauge rewire

[MisterCinders]

I replaced my gauge cluster with some smaller gauges from Dime City. They are tres sexy.

Now I have a wiring puzzle.

The new gauge only has a single blinker indicator, not one for each. The wiring options are wacky.

Tried merging the signal wires through the lone indicator path. That turned my turn signals into hazard lights. All of them flash if you flip the switch left or right.

Tried wiring them straight through, bypassing the gauge altogether. That didn't work. In that configuration the turn signal switch flashes all lights, including the tail and headlight.

What can I do?

[pete]

You need to get a couple of diodes.

One for the feed from the left and one for the feed from the right.

This will let the feeds flash the indicator light on both sides, but the diodes only allow current to flow in one direction and therefore the left flashers won't flash the right and vice versa.

At the moment, the connection to the gauge lamp is acting as a connection from left to right and vice versa.

I'm not sure what size diode you would need though but they're rated in amps...

[MisterCinders]

So install diodes between the power and the indicator? Do I then siamese into the gauge wire?

[pete]

Ok, I'm crap at explaining this so I'll do my best with the assistance of Google...

First of all, I'm going to assume your original gauges had a separate light for left and right.

There's a stripe on the diode that indicates the cathode end, and this is the end of both diodes that you want connected to your gauge light.

The anode end of each diode you want connected to whatever wire used to feed the stock gauge indicator light.

I've attached a diagram that I hope makes a little more sense...

Basically the diodes stop the current flowing to the other indicator circuit, ensuring your left and right indicators stay isolated from each other.

Apologies for the crap explanation but hopefully it's enough to help you out, and as for what diode to use, probably just a IN4004 1 amp diode or something equivalent would be sufficient.

[oneliterbeater]

Let's see a pic of those guages.

[MisterCinders]

Let's see a pic of those guages.

Here they are.

[pete]

Any joy on the diodes yet at all? Did what I said even make sense? I know I don't explain these things terribly well...

[MisterCinders]

What you said made sense. Couldn't find the damn diodes at AutoZone. Trying to figure out where to buy these parts.

[obsidianghost]

radio shack has diodes. Test the amperage on your turn indicator circuit so you know what size diode to get. This one might be just the ticket:

http://www.radioshack.com/product/index.jsp?productId=2062577&filterName=Type&filterValue=Diodes

3A Barrel Diodes Model: 276-1141. Some stores still carry this stuff but if not they will ship it to your nearest store for free.

[MisterCinders]

radio shack has diodes. Test the amperage on your turn indicator circuit so you know what size diode to get. This one might be just the ticket:

http://www.radioshack.com/product/index.jsp?productId=2062577&filterName=Type&filterValue=Diodes

3A Barrel Diodes Model: 276-1141. Some stores still carry this stuff but if not they will ship it to your nearest store for free.

Thanks for the link. There is a Shack near my house, so these will be the ticket.

Will 3 amp diodes be too much? Should I use a 1 amp diode?

[pete]

As long as it's rated over 15 volts or so 3A will be fine, better to go too big than too small. As obsidianghost said, measuring the current will be the safest, but you can get a reasonably accurate idea using the formula Power = Volts x Current.

I'm not sure what wattage the indicator lamps are, but if they're 2 watts each for example, current for one side will be Power/Volts = Current, so 4 (two bulbs)/12 = 0.333 amps.

Not sure how much electrical work you do so apologies if this is basic stuff, but make sure you solder them in well and use heat shrink over the top to insulate them well. I'd probably just put one piece of heat shrink over the diode and soldered connections to make it easier and neater, but probably best to give the modification a quick test before actually shrinking the heatshrink (making sure the connections are away from the chassis etc.).

[Steve]

Will 3 amp diodes be too much? Should I use a 1 amp diode?

A 1 amp diode will be fine, because the only current that will be going through it is to light the indicator on the 'dash', and that only takes a small fraction of an amp.

If you can only find something larger than 1 amp, that's OK, too, it will work just fine.

.

[pete]

A 1 amp diode will be fine, because the only current that will be going through it is to light the indicator on the 'dash', and that only takes a small fraction of an amp.

If you can only find something larger than 1 amp, that's OK, too, it will work just fine.

.

Argh! Thanks Steve, morning coffee mustn't have kicked in yet... MisterCinders ignore my example... only the wattage of the gauge light is relevant as Steve says...

[MisterCinders]

As long as it's rated over 15 volts or so 3A will be fine, better to go too big than too small. As obsidianghost said, measuring the current will be the safest, but you can get a reasonably accurate idea using the formula Power = Volts x Current.

I'm not sure what wattage the indicator lamps are, but if they're 2 watts each for example, current for one side will be Power/Volts = Current, so 4 (two bulbs)/12 = 0.333 amps.

Not sure how much electrical work you do so apologies if this is basic stuff, but make sure you solder them in well and use heat shrink over the top to insulate them well. I'd probably just put one piece of heat shrink over the diode and soldered connections to make it easier and neater, but probably best to give the modification a quick test before actually shrinking the heatshrink (making sure the connections are away from the chassis etc.).

I am pretty new at this, but I generally follow this process

twist wires and tape
test result to make sure I didn't screw it up
then solder and heat shrink

[obsidianghost]

The leads on a diode aren't like regular copper wire, you don't want to twist it much. I would solder everything together, test and if it all works shrink the heat shrink. unsoldering a connection is just as easy as soldering it. Their should be an arrow on the diode telling you which way to put it in, the arrow should point from positive to negative. probably toward the gauge light in your case.