The tom tom one battery has three leads; red yellow and black. what is the yellow lead for?

I assume you mean the plug that goes into the 120VAC receptacle in the wall? and when you say leads, I assume you mean the leads that go to the battery. the leads are of course red/Positive Black/negative. generally the plug to the wall would not have black and red wires. it would normally be Black/hot, white/neutral, and green/ground.

if it has European colors for the 120VAC plug in the wall then it would be Brown/hot, Blue/neutral, and green/ground. (sometimes it may be green with yellow stripes or something like that)

I have yellow blue red and black how to hook those up?

Connect black to earth or battery negative.
Connect red to battery positive or the acc lead from your ignition switch. If connected to acc the unit will power down when the vehicle is switched off. If connected to battery positive it will remain on irrespective of ignition switch position.
Connect yellow to battery positive for memory power. The moment this lead loses power all the settings/memory on the unit will be lost.
Leave a comment if you require further assistance

Here's how it goes:
Speaker wires:
grey=right front pos.
grey/black=right front neg.
white=left front pos.
white/black=left front neg.
violet=right rear pos.
violet/black=right rear neg.
green=left rear pos.
green/black=left rear neg.
red=12 volt switched power source
yellow=12 volt constant power source (direct to battery)
black=chassis ground
orange/white=illumination (switched source,not to head light switch)
blue/white=amp turn on lead (to remote turn on lead of amp)
blue=auto antenna (switched power source)
brown=phone mute lead (to cell phone mute lead)
RCA connector leads:
grey lead:
red=right front
white=left front
black lead:
red=right rear/right rear subwoofer
white=left rear/left rear subwoofer
(connect to external amp)
red lead:
red=right aux input
white=left aux input
(connect to external unit)
green lead:
red=right dual zone output
white=left dual zone output
(connect to wireless head phones)
That should be all there is. on the yellow that goes direct to the battery you need to use an inline fuse holder with 30 amp fuse.

yes it could be

check your battery 1st , then check the stator a/c output

• 10 or 16 Amps DC regulated for charging
battery
• Two black leads (C) from stator
• Yellow connector (D) with two pin
terminals
• Two yellow leads (E) to regulator-rectifier
(F)
• One red lead (B) from regulator-rectifier
to red connector output lead (A)
• 10 and 16 Amp systems use the same
stator, color coding and regulator-rectifier
• Alternator output is determined by the
flywheel alternator magnet size


The stator and regulator-rectifier are the same
for the 10 and 16 Amp systems. The system
output is determined by the flywheel magnet
size.
Test Alternator Output
1. Temporarily disconnect stator wire
harness from the regulator-rectifier.
2. Insert RED test lead (A, Figure 28) into the
V ω receptacle in the meter.
3. Insert BLACK test lead (B) into COM
receptacle.
4. Rotate selector to AC Volts position.
5. Insert RED (A) and BLACK (B) test lead
probes into output terminals (D & E) in
YELLOW connector (C). (Test clip leads
may be attached to either terminal).
6. With the engine running at 3600 rpm, the
output should be no less than:
• 20 volts - 10 Amp System
• 30 volts - 16 Amp System
7. If No or Low output is found, check for
bare wires or other defects. If wiring
defects are not found, replace the stator.
voltage depending on alternator type and magnet size

then check the regulator / rectifier , make sure it is grounded properly

make sure battery earth lead is good

i suspect loss of bat voltage is letting the afterfire solenoid close off the main jet

let me know model and type codes off engine & i will try help further

cheers

Locate & route Black lead to ground / 2004-later softail: On the frame strap under the seat directly in front of the battery.

Locate & route the pink lead to Signal / For 2004 & later FXST/C/I The #3 cavity in the connector {39b} on the back of the speedometer. The socket terminal on the signal (pk) lead fits the #3 cavity.

Locate & route the Orange and white lead to power / Ummm.. it's saying for 2004 and later to adapt to the fuse block For earlier [ For 1996 to 2003 softail: locate the power lead (o/w) in the tail lamp pin connector {7a} under the seat behind the right rear corner of he battery.] "here you are looking to run it to a fused line, not directly to power/battery" I hope this helped.

Not sure why you would need to know this , red is live black is return circuit and the yellow is auxilliary and usually goes to charge input. as a live wire It is easier to cut and graft a new battery to the stubbs of wire than to solder new battery on. What you might really be needing is the polarity.. whether any charge pin is positive or negative if you are making a new internal charge point. Consult the back of the charger it usually states the polarity in a graphic.

Brown wire-Phone mute Yellow 3A-Bus power lead Yellow 15A-Memory backup lead Red-Power lead Blue/White-Amp lead Black-Ground Orange/White-Illumination lead Blue-Auto antennae SPEAKERS(black strip is -ive) gray+gray/black-front right white+white/black-front left purple+purple/black-rear right green+green/black-rear left

YELLOW goes to the battery lead
RED goes to the ignition on lead
BLACK goes to chassis ground

Black and Red. ( red is + ) The yellow wire is a sensor wire but you just need black = neutral , red = Positive.
Please don't be offended. To be honest with you , if you didn't automaticly know this or be able to deduce this with a multimeter, then perhaps you should not be messing with it at all.