BND Night crawler electronics issues

[du4x4]

Hi, I am having some issues with my electronic. The ESC RX and Motor are the stock Losi parts the truck came with. The Servo is a Hitec 7955 TG. When I turn on the power at the switch, if the servo is plugged in, nothing will come on. If I unplug the servo, the lights in the RX and ESC come on as well as the LED driving lights. However, I do not get any throttle. I have tried two different RX's so I think it is the servo that is the issue. Does this sound right? Any one have any suggestions if you don't think it is the servo?

The whole truck is right at 3 months old, so I am a little perturbed that I am having issues already.

Thanks!
Clayton Grove

[JeremyH]

Lipo? If so, what voltage? External BEC?

[du4x4]

7.2 volt NIMH (I know, but it was all I could afford at the time), I was using an external CC BEC set to 6 volts when it started doing this, but with it unplugged, It still happens. I am getting 6 volts out of the BEC though. With the BEC plugged in, if I plug the signal wire in, it shuts everything down like I plugged in the servo normally.

[JeremyH]

When you unplugged the BEC, did you plug the red ESC wire back into the harness? How do you have the BEC wired? Directly to the servo or like Castle recommends?

[du4x4]

I wired the BEC directly to the servo, with the signal wire off of the servo connected to the signal post on the RX.

[JeremyH]

so, you have it wired like this:

??

[du4x4]

Yes, it the BEC was wired exactly like that.

[JeremyH]

Hummm......if you test the motor and servo, one at a time, you might be able to narrow it down. Try plugging the servo into the Throttle port on the RX, leaving the motor unplugged and start up the truck. See if the servo works properly (obviously, it will be controlled by the throttle trigger).

[du4x4]

good idea. I will give it a shot.

Thanks!

[du4x4]

So I went out to try your suggestion and realized that if I unplug the motor, I lose power to the RX. While I was out their, I put my continuity tester on the the positive and ground leads on the servo and discovered that I have continuity while it is unplugged. Does this sound normal, or do you think I have a short in my servo?

[JeremyH]

That is very strange...it sounds to me like there might be a problem with the Rx. You said that you have tried two receivers, did they both do the exact same thing? Do you have the stock servo that you can try?

[du4x4]

Both receivers do exactly the same thing. When I turn it on with the servo plugged in, nothing comes on. If i unplug the servo, all of the lights come on, but I don't get any throttle response. I don't have the stock servo any more unfortunately. It went into the trash as soon I saw all of the teeth stipped off the gears.

[JeremyH]

That is weird. I wouldnt think youd have problems like that with the servo, but I guess anything is possible.

It doesnt make sense to me why, if there is an issue with the servo, the motor wouldnt come on after the servo is unplugged....

[du4x4]

Do you think I could have shorted the ESC somehow?

[JeremyH]

Maybe, but for both problems to persist, there would need to be a problem with the ESC and the servo. The only common link between them is the Rx...

[du4x4]

I thought the same thing. That's why I talked Losi into sending me another RX. Needless to say, I was pretty dissapointed when the new RX did the exact same thing as the old. I guess I will take it to a a local hobby shop to have them tell me whats wrong with it.

[JeremyH]

Yeah, that might be a bit more helpful....it should be easier to diagnose it in person...

[du4x4]

Of course, this may be a fine time to upgrade all of the electronics too....

[DezertCrawler]

Are you useing the batteries that came with the radio from losi? If so they may be toast. I got a LNC and used theyre stock AA batteries and my radio kept messing up. I didnt think anything of it until i got my 3rd radio from losi and used brand new batterys. I had the same issues you have. what it was, was the radio wasnt storeing its bind because the batterys were toast. Also if the batteries arent good the radio will make a weird noise.

[du4x4]

So it turns out that I have a short in the servo. I put a continuity tester on the positive and ground terminals and have continuity where I shouldnt... so off to Hitec it goes! Thanks for everyone's help!