Which Terminal on key switch

[garysmith39555]

2006 Precedent. I have carefully(and successfully) installed a 48V to 12V converter. The output wires from the converter read 12V. As I prepare to run the wire to the dash, my question is which terminal on the key switch is the one to which I attach the wire? Also, do I need to disconnect the main pos/neg wires again to make this connection or is "tow" mode sufficient?

[jakesnake27]

You want to attach the trigger wire to the 'cold' side of the key switch. Simply use your multimeter to determine which terminal only has 48v when the switch is on.

For safety, go ahead and disconnect one of the battery cables in addition to flipping the run/tow switch to tow.

[garysmith39555]

By "cold" side, do you mean the terminal with zero voltage and wouldn't the other terminal have only 12V?

[jakesnake27]

Which wire are you running to the dash, what is its purpose?

[NoleFan4Ever]

And to Jakes point, is this the 48v supply wire or the trigger wire? You do not want to run the supply wire from the switch like some will do with small 4 wire converters.

If it has a trigger wire, that goes to the cold side of the switch. If it is a 48v supply wire, it goes to the pack Pos (+) and will be a hot (on) converter all the time or you need to run a 48v relay from it to the cold side of the switch.

[yawood]

To clarify what Nole and Jake said we need to know if you have a 5-wire reducer or does it just have 4 wires?

If you have a 4 wire reducer:

• the +48V wire goes to the positive of No 1 battery
• the -48V wire goes to the B- attachment (on the Precedent there is a black wire with a yellow bullet connector behind the batteries)
• the 12V leads from the reducer will now give 12V and the reducer will be on permanently.

If you have a 5 wire reducer:

• the +48V wire goes to the positive of No 1 battery
• the -48V wire goes to the B- attachment (on the Precedent there is a black wire with a yellow bullet connector behind the batteries)
• the Trigger wire goes to the "cold" side of the key switch (the side that only has power when the key is on)
• the 12V leads from the reducer will now give 12V only when the key is on.

If you don't have a multimeter to test which is the cold side just connect the trigger wire to one side and see if the reducer is off (no 12V) when the key is off. If not change the trigger wire to the other side.

[NoleFan4Ever]

Yeah, what he said! Lol!!

[kantuckian]

Good Info

[yawood]

A few things to add to what I said above:

• You should put a fuse in the +48V line as close as possible to the battery.
• If you have an OBC, the -48V must go to the B- or the cart will not charge properly because the OBC will not know how much power has been taken from the batteries by the reducer.
• You can make a 4-wire reducer switch off with the key by adding a 48V relay. The wires from the key will switch the relay on (with a small amount of power) and the relay switches the reducer on and can carry the larger power that it needs.
• It is best to run your 12V wiring through a fuse box and negative buss to your 12V accessories. Then they are properly fused in case of a short.
• You always run your 12V negatives back to the reducer. NEVER use the cart chassis to "earth" the negatives as you would on a car or truck.

[garysmith39555]

Thanks yawood! I have a 5 wire reducer and my simple mind understands your connection instructions completely.