[Difine]

I extended my new 50 ft low voltage garden lights with a 17 ft wire using a low voltage cable connector. The 50 ft is 12/2 with 7 lights and the 17 ft is 16/2 with 3 lights. All 10 have 4 watt bulbs. The 3 lights work and the 7 won't work, even when I remove the extended wire. The control unit is a 48 watt (input 120 vac, 60 ha, .42 amp. Output max 48w, 12 vac) All connections and bulbs are good. What have I done wrong since I can't even get the 7 lights on the 12/2 to work solo?

 

[FrodoOne]

The key points of this query are specified as

I extended my new garden lights using a low voltage cable connector. The "original" was with 7 lights and the "new" is with 3 lights. The 3 (new) lights work and the 7 (original) won't work, even when I remove the extended wire. All connections and bulbs are good. What have I done wrong since I can't even get the (original)7 light to work solo?

It seems that the OP is saying that the new set of lights - attached to the supply at the end of a previously existing set of lights - is now working BUT, the previously existing set of lights, along the supply to the new lights, is now NOT working !
(Presumably, there has been no change in the connection of the "original" set-up to the supply.)

While the OP states "bulbs are good", the foregoing seems to be completely inexplicable to me - UNLESS somewhere in the set-up process a relatively high voltage has been applied to the "original" 7 lights and they have "blown". I can only suggest that one or more of these original 7 lamps be tested, to see if they are actually still operative, before proceeding any further.

 

[danpik]

Can you check the bulbs and sockets with a Volt/OHM meter? Are the original 7 bulbs in series or parallel?

 

[George6488]

What is rating of the transformer powering all this?

 

[FrodoOne]

What is rating of the transformer powering all this?

The OP stated "Output max 48 W, 12 V AC" - so it should be possible to run 12 - 4 W bulbs.

 

[Difine]

So I fiddled with reinstalling each light to the wire and finally got several working. I have two other identical sets and never had this much trouble. So I should be able to get them all going somehow. So my remaining question is:

Is it okay to extend the existing set which uses 12/2 gauge with a 16/2 gauge wire? i.e. Mix the gauges?

 

[Oso954]

Is it okay to extend the existing set which uses 12/2 gauge with a 16/2 gauge wire? i.e. Mix the gauges?

It's not normally recommended, and can cause voltage drop problems particularly with longer extensions.

However, with your small system and the limited wattage, you should be fine.