Can someone help me with rechargeable led powersupply

I have a K Light custom built belt light I got from a friend but someone went in and messed with the wiring I can find any diagrams for it and would really like to get it charging again can someone please help me with this if you could just tell me what each of the wires on the battery are for it would help a great deal there are four red,brown,blue and black

Do you have any voltmeter?

I see nothing but a NiCd or NiMh battery pack with an imbeded thermostat. The 5Ω power resistors either provide current-limiting during charging or they are the ballast resistors for the LEDs in the lamp head?.

The thermostat is supposed to terminate charging when then pack heats up after reaching full charge.

What is the external power supply (not shown in your pictures) but is likely the most critical component of the whole system. That would tell us what the resistors are doing.

External input may be 20vac coz battery out is 18vdc