Testing trim position sender

[deanbrantley]

So I bought new senders for my alpha 1 gen 2. The limit sender works fine however my position sender makes my trim gauge peg either 100% up or down. So I thought to myself the new sender is bad, knowing that its nothing more than a rheostat I figure I could disconnect the leads from the pump, hook my ohm meter between the wires on the puck and test resistance. I get 000.1 to 000.2 no matter how far I turn it. I take it apart and clean it, still the same. Does anybody know what the resistance should be or is my thinking flawed?

 

[Bt Doctur]

"I could disconnect the leads from the pump"

You could but they go to the trim limit switch , the sender wires usually connect at the front stbd side of the motor.

 

[alldodge]

So I bought new senders for my alpha 1 gen 2. The limit sender works fine however my position sender makes my trim gauge peg either 100% up or down. So I thought to myself the new sender is bad, knowing that its nothing more than a rheostat I figure I could disconnect the leads from the pump, hook my ohm meter between the wires on the puck and test resistance. I get 000.1 to 000.2 no matter how far I turn it. I take it apart and clean it, still the same. Does anybody know what the resistance should be or is my thinking flawed?

I think you have a bad sender, your measuring the wrong leads, or you installed the limit where the sender should have been.

The sender should read from zero to about 80 ohms. The wires were just held by keeps on the pump, they actually don't go to the pump, correct?

 

[wrench 3]

The trim sender connects to a brown with white stripe wire and a black wire.

 

[achris]

Sounds like you may have 'Limit' and 'Sender' transposed. Sender should read 33 ohms to 240 ohms. Limit will be either open or closed. The senders are marked on their covers, TL and TS. TL goes on the port side and TS goes on the starboard side.

Chris......

 

[deanbrantley]

Bt Doctur they can't. Sender is male/male so is pump. Leads on stbd side engine male/female so are the limit wires.By the way the limit works fine. Took trim sender completely apart, just the wires and the puck, measured ends of each wire and got 0 then 18, then 30, 28 on each wire. Now for something weirder then I measured between wires and got 8-9 ohms?

 

[alldodge]

You know, if you bought a Sierra sender, this is probably the issue. IMO they are very poor quality and don't last

 

[achris]

Bt Doctur they can't. Sender is male/male so is pump. Leads on stbd side engine male/female so are the limit wires.By the way the limit works fine. Took trim sender completely apart, just the wires and the puck, measured ends of each wire and got 0 then 18, then 30, 28 on each wire. Now for something weirder then I measured between wires and got 8-9 ohms?

I wasn't talking about the wiring being transposed, I was talking about the senders themsleves. And yes, the 'sender' can work in the 'limit' side. As the drive goes up the resistance increases and eventually the relay switching the pump motor will drop out, making it appear as the 'Limit' switch is working correctly.

Chris.........

 

[deanbrantley]

Cant argue with you there, it is a Sierra unit. But really the whole puck is 2 wires and a rheostat. I could see getting no reading at all, broken wires=open circuit. But to get the readings I'm getting, and on both wires? It just pisses me off, as it does all of us, to spend $$ on something that's so incredibly cheap to make, takes a lot of time to install, and then its worthless. Sierra could actually hire a teenage sweatshop worker in Malaysia for $5 a day to test hundreds of these, after they get them made for $2 bucks apiece in Vietnam, But that might cost them to much since they only get $90 for a set of them from suckers like me! Solution: I really don't need a trim gauge. Thanks everybody for listening, the pain killers are taking over now, I feel a lot better.