voltage drop

[ctkiteboarding]

i have installed a perfectpass speed control on my ski boat, when i start the motor the unit powers down,, im told its beause of a voltage drop i tested the battery and it reads 12.4 when i test the module's power lead it reads 11.7??? what can cause the voltage loss?

 

[JB]

Re: voltage drop

Wire is too small, ct. Go up (down in AWG number) a couple of sizes.

 

[tommays]

Re: voltage drop

well 12.4 at the battery is allready LOW and how low does it drop during cranking ?

what do you have for a drive ? It can be as simple as the 10 pin plug on a merc inboard needing to be cleaned and pluged in again

Tommays

 

[ctkiteboarding]

Re: voltage drop

well 12.4 at the battery is allready LOW and how low does it drop during cranking ?

what do you have for a drive ? It can be as simple as the 10 pin plug on a merc inboard needing to be cleaned and pluged in again

Tommays

im sorry I did not say it was a 200 merc o/b on a mastercraft barefoot boat,,

i was told that because my speed control module's power lead is wired at the tach and not the ignition key that maybe where it drops?

what should a battery that is charged fully read with the engine off? it reads 13.7 when running seems to be charging well

 

[JB]

Re: voltage drop

12.6V is correct when not being charged, ct. It may drop to as little as 11V when cranking. If it drops more than that your battery may be too small or not in good health.

To read 11.7V at the unit when the battery is at 12.6V you are dropping almost a full volt in the wiring. That is why I said wire is too small. Rewire it to the acc pin on your ignition switch and use #12 or larger wire.

Good luck.

 

[drewpster]

Re: voltage drop

Another possibility could be a bad connection or corroded wire. Make sure your meter has a good ground when checking.

 

[cjames]

Re: voltage drop

a slightly bad connection can read full voltage at no load, then turn the device on, and voltage drops. Its bit me a few times...

 

[Texasmark]

Re: voltage drop

If your problem is a corroded terminal on a connector, run the system for an hour or so and feel the connector. If warm you have your drop.

Agree with the above. Wiring to the tach (mine at least) is like 20 AWG or less and not capable of supplying much current to anything.....tach draws very little current so they don't use a big wire for it.

Everybody has their own sweet spot for battery charge. Mine is 12.75 after the battery has had time to stabilize from any charging it may have received.

Mark