Page 1 of 1

Water Temperature Senders

Posted: May 10th, 2020, 12:49 pm
by jms642
My 350 Crusaders each have two water temp sending units and my boat has dual stations. After a recent overheating incident, I replaced the thermostat, water pump, and senders. Then the ignition fuse started blowing. This morning I disconnected the single wires from each of the new senders and bingo, no more fuse problems. Of course, I don't have working water temp gauges either. I'm wondering if anyone knows whether those senders should be for dual station? I assumed that two identical units with one wire each were only serving one gauge. I just bought two new dual station senders, but hesitate to install them without asking one of you really smart folks. Thanks for any advice!

Re: Water Temperature Senders

Posted: May 10th, 2020, 1:22 pm
by bud37
Welcome to the forum....

Is one of those a sender and the other an alarm switch for each engine? Dual stations should always have dual station senders to match the gages. Don't use thread tape when installing....ground thru the block.

Did you match the numbers of the senders and switches you took out with the new ones ? Hopefully you still have the old ones.

My guess here, hard to say without seeing for me.

Re: Water Temperature Senders

Posted: May 10th, 2020, 4:55 pm
by Viper
Welcome aboard.

On each sender post where the sender wire is hooked up, in some cases there should be a small non metallic washer to prevent the sender wire from touching the grounded housing. The post is isolated from the grounded metal housing but if the washer is missing, your sender wire connector is likely shorting to ground and blowing your fuse. Check to ensure the connector on the wire is not in contact with the metal housing and let us know.

Re: Water Temperature Senders

Posted: May 10th, 2020, 5:12 pm
by jms642
bud37: thanks a million for the reply. The old ones (original = 33 years old) broke when I took them out, so I'm stuck with new ones. Will install the dual station senders and see how it goes.
Viper: Thanks so much. That's the ticket. These new ones (from West Marine) did not come with non-metallic washers. Clearly, this is why the fuse was blowing. I'll pick up a couple and try again.
You fellows are mighty kind to help!

Re: Water Temperature Senders

Posted: May 10th, 2020, 5:20 pm
by Viper
Keep us posted. The 4207 is a nice boat by the way, no shortage of room there :down: I bet the Crusaders look small in that engine compartment.