How to Test a Bug Zapper Transformer

[bishopNlouisiana]

I've searched the internet for an answer without success, so I hope some of the experts here might help me.

I have an old 3 Acre Bug Zapper I bought from Sears 25 years ago.

It's been in storage for 20 years and I pulled it out to use because we have had several Hurricanes this year, the Mosquito population is very, very bad.

It's old and before modern electronics so it just has three transformers. two for the two bulbs and one big transformer for the spark. This old thing worked great and made a light show every evening for hours.
I opened it up and nothing is burnt and the wiring is intact.

The two bulbs still light up but there is no spark for thee bugs..

Does any one hear know how to test a transformer? I have a Fluke multimeter but I don't know what I'm looking at.

A 3 acre bug zappper is rare. I found a like big transformer online for $40, but I want to test the old one first. It's 4" long and 3" tall. Two wires for power and two wires for the spark grid work.

Can anyone share a link to a site that might help me with this?

 

[Dusty MI]

With it unplugged, set your meter to ohms. With one leads on the zapper wires it should show continuity.

Dusty

 

[P I Pete]

The transformer sounds like one on an oil fired furnace.

Pete

 

[Janicholson]

Do not test it plugged in. Set your meter on ohms. Disconnect one of the input leads from the suspect transformer. Touch the disconnected lead with (either)
lead, and the still connected lead with the other. The reading should be 10 to 20 ohms, not zero ohms (unlikely) or infinite ohms, more likely.
If a middle reading as above, test the output leads by just touching the adjacent wires where a bug would explode. These will have thousands of ohms, maybe
10,000. If no ohms, or infinite ohms the transformer is bad. Before condemning it, make sure all connections are clean and tight. If the transformer in
question is in the same "ON" circuit as the others, the switch is good. If different, you might trade the terminal for one of the ones that go to a black light
to see if the switch is bad. Jim

 

[Steve@Advance]

The likely reason it is not working is either the transformer is bad, or the grid is shorted.

Try disconnecting the transformer secondary leads, position them very close to each other but not touching, plug it in, see if it will make a spark.

If it does, reconnect one lead to the grid, position the other very close to the other grid terminal but not touching. If it arcs, the grid is shorted.