Is it 12v or 24v, no markings!!!

I know this is a long shot and very vague.

I picked up 3 lower units of trolling motors and cannot find any markings on them (for $30 I wasn't gonna argue)

They look to be larger units (bigger than the #40iirc unit I had on my old boat), 2 of them have just 2 wires (RED & BLACK)
The third has 4 wires Larger red & black then smaller yellow and white.

Does anyone know a way to figure out the volts of the motor from the Ω? or some other way?

I have a PWM box that can (supposedly) handle 10v-55v that I was going to use to control it I just want to know if there is a way to figure out the proper voltage.

They all currently run on 12v but thats just holding it in the air while I touch the leads so that doesn't say much.

I've thought of just wiring them on the PWM with 24v and running them and if I get up to about %50 and they feel like they are running full load that would suggest that to be a 12v motor. (I was also thinking of monitoring the amps on the output via my amp clamp)

This is about how the other 2 look they just have the 2 blade weedless props which make me think they are minn kota (the white pieces are PVC to mount onto my canoe)

measuring the power consumed vs load would be more accurate than anything else i can think of...but I'd be inclined to start with 12VDC ...

Look for typical RPM of trolling motors and find a way to check these- if they seem to spin like they're spinning extremely fast at 24VDC, they're probably supposed to be working with 12VDC.

jimn said:

Look for typical RPM of trolling motors and find a way to check these- if they seem to spin like they're spinning extremely fast at 24VDC, they're probably supposed to be working with 12VDC.

Click to expand...

I checked at 12.35V I got 964 RPMs and at 24v (didnt measure the exact volts) i got 1975 rpms.

It didnt let the smoke out so thats good.

A DC motor will run at either voltage no problem. 24V may run it too fast

And that's my dilemma. I cant find very consistent information on the rpm of a typical electric trolling motor. But 1850 rpm does seem like a somewhat consistent number that pops up which makes me think it is a 24v motor.