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Problem with Childs 12v 4x4 car - from an Electronics dummy!

Started by BobbyDazzler October 12, 2011
I can test a circuit and check if there is powere on switches and
cables but that tis the total knowledge of electronics I have :o(

I was given a childs 12v rideon 4x4 which wasn't working.  If I switch
it on and press the accelerator pedal (swtch) nothing happens.  I have
replaced the battery and can follow the current right through to the
motors but nothing happens.  I have wired the motors directly from the
battery and they work fine.  With such a basic knoweldge of
electronics I don't understand what is wrong?  The only thing that is
slightly confusing is a small Joemex 77 series "thingy" which I
believe acts as a thermal cutout (assuming works for a period of time
as there is no button to reset it)  Can anyone offer any words of
wisdom?
BobbyDazzler wrote:
> I can test a circuit and check if there is powere on switches and > cables but that tis the total knowledge of electronics I have :o( > > I was given a childs 12v rideon 4x4 which wasn't working. If I switch > it on and press the accelerator pedal (swtch) nothing happens. I have > replaced the battery and can follow the current right through to the > motors but nothing happens. I have wired the motors directly from the > battery and they work fine. With such a basic knoweldge of > electronics I don't understand what is wrong? The only thing that is > slightly confusing is a small Joemex 77 series "thingy" which I > believe acts as a thermal cutout (assuming works for a period of time > as there is no button to reset it) Can anyone offer any words of > wisdom?
Does it look like this?> http://www.joemex.com/produce/77.asp?add=Product&add2=77 Series --Winston
On Oct 12, 3:50=A0pm, Winston <Wins...@BigBrother.net> wrote:
> BobbyDazzler wrote: > > I can test a circuit and check if there is powere on switches and > > cables but that tis the total knowledge of electronics I have :o( > > > I was given a childs 12v rideon 4x4 which wasn't working. =A0If I switc=
h
> > it on and press the accelerator pedal (swtch) nothing happens. =A0I hav=
e
> > replaced the battery and can follow the current right through to the > > motors but nothing happens. =A0I have wired the motors directly from th=
e
> > battery and they work fine. =A0With such a basic knoweldge of > > electronics I don't understand what is wrong? =A0The only thing that is > > slightly confusing is a small Joemex 77 series "thingy" which I > > believe acts as a thermal cutout (assuming works for a period of time > > as there is no button to reset it) =A0Can anyone offer any words of > > wisdom? > > Does it look like this?>http://www.joemex.com/produce/77.asp?add=3DProduc=
t&add2=3D77Series
> > --Winston
Yes, except it doesn't have the threaded bit at the top, mine is black and completely flat on the top.
On Wed, 12 Oct 2011 07:47:01 -0700, BobbyDazzler wrote:

> I can test a circuit and check if there is powere on switches and cables > but that tis the total knowledge of electronics I have :o( > > I was given a childs 12v rideon 4x4 which wasn't working. If I switch > it on and press the accelerator pedal (swtch) nothing happens. I have > replaced the battery and can follow the current right through to the > motors but nothing happens. I have wired the motors directly from the > battery and they work fine. With such a basic knoweldge of electronics > I don't understand what is wrong? The only thing that is slightly > confusing is a small Joemex 77 series "thingy" which I believe acts as a > thermal cutout (assuming works for a period of time as there is no > button to reset it) Can anyone offer any words of wisdom?
Yes -- something's broke. Isn't that helpful? You say you can follow the current right through to the motors -- what do you mean? When the accelerator pedal is depressed (I assume it's just a switch), there should be 12V across the battery terminals, and nearly 12V across the motor terminals. This means that the circuit path from the battery '+' terminal to the motor '+' terminal should have very little voltage drop, as should the path from '-' to '-'. So, one way to chase this down is to hold down the accelerator, and trace down the point where you have a 12V drop in the circuit, instead of in the motor. When you find it, you've identified the bad spot. -- Tim Wescott Control system and signal processing consulting www.wescottdesign.com
BobbyDazzler wrote:

(...)

>> Does it look like this?>http://www.joemex.com/produce/77.asp?add=Product&add2=77Series >> >> --Winston > > Yes, except it doesn't have the threaded bit at the top, mine is black > and completely flat on the top.
What Tim says. Place your negative meter lead on the negative battery terminal. With the 'accelerator' depressed, place your positive voltmeter lead on one terminal of the Joemex breaker and note the reading. Then place your positive voltmeter lead on the other terminal of the Joemex breaker and note that reading. Both readings should be about the same, 12 V or more. --Winston
On Oct 12, 10:47=A0am, BobbyDazzler <david.a.mitchel...@googlemail.com>
wrote:
> I can test a circuit and check if there is powere on switches and > cables but that tis the total knowledge of electronics I have :o( > > I was given a childs 12v rideon 4x4 which wasn't working. =A0If I switch > it on and press the accelerator pedal (swtch) nothing happens. =A0I have > replaced the battery and can follow the current right through to the > motors but nothing happens. =A0I have wired the motors directly from the > battery and they work fine. =A0With such a basic knoweldge of > electronics I don't understand what is wrong? =A0The only thing that is > slightly confusing is a small Joemex 77 series "thingy" which I > believe acts as a thermal cutout (assuming works for a period of time > as there is no button to reset it) =A0Can anyone offer any words of > wisdom?
Do you have some way to check the switches (DMM perhaps). Several years ago I pulled a few of these from the trash and found that the rocker switches were shot. I replaced 'em with some toggle switches, and away the boy went. George H.
On Wed, 12 Oct 2011 07:47:01 -0700 (PDT), BobbyDazzler
<david.a.mitchell66@googlemail.com> wrote:

>I can test a circuit and check if there is powere on switches and >cables but that tis the total knowledge of electronics I have :o( > >I was given a childs 12v rideon 4x4 which wasn't working. If I switch >it on and press the accelerator pedal (swtch) nothing happens. I have >replaced the battery and can follow the current right through to the >motors but nothing happens. I have wired the motors directly from the >battery and they work fine. With such a basic knoweldge of >electronics I don't understand what is wrong? The only thing that is >slightly confusing is a small Joemex 77 series "thingy" which I >believe acts as a thermal cutout (assuming works for a period of time >as there is no button to reset it) Can anyone offer any words of >wisdom?
--- Lift the wheels which are providing traction, switch it on, and place a jumper across the accelerator terminals. If the wheels spin you have a bad switch. -- JF
BobbyDazzler wrote:
> I can test a circuit and check if there is powere on switches and > cables but that tis the total knowledge of electronics I have :o(
(...) What did you find out, Dazz? --Winston
On Thu, 13 Oct 2011 07:02:27 -0700, Winston wrote:

> BobbyDazzler wrote: >> I can test a circuit and check if there is powere on switches and >> cables but that tis the total knowledge of electronics I have :o( > > (...) > > What did you find out, Dazz?
Your public wants to know. -- www.wescottdesign.com
Tim Wescott wrote:
> On Thu, 13 Oct 2011 07:02:27 -0700, Winston wrote: > >> BobbyDazzler wrote: >>> I can test a circuit and check if there is powere on switches and >>> cables but that tis the total knowledge of electronics I have :o( >> >> (...) >> >> What did you find out, Dazz? > > Your public wants to know.
:) --Winston