problem with hydro-quip hq-2000 (solved)

[koby411]

i own a no name hot  tub for many years and have been successful to keep it running but now i am confronted with  a problem i can't seem to solve on my own. if there is someone that cold guide me to find out what to do i would be thankful.
the unit i have is a hydro-quip   hq-2000. i know it is old but i live on a limited budget and i use the hot tub for pain relieve instead of medication. (this link shows the item and its parts list.  https://www.aquaman.com/schematic.asp?kc=S1901 )
 it is connected to a 220v  breaker. it has 2 air switches on the top  as the only controls (there is no board inside) one for light  the other one to turn on high speed on the pump . low side of pump comes on via timer, set filtering or temp set heat and filtering. now when i try to turn on light there is none also when turning on pump via air switch or timer/thermostat there is a bad buzzing from contactor but nothing comes on 
so i replaced the contactor with a new one but same result .i also exchanged both relays in the unit but same ..nothing but a buzzing (no movements not a clicking) noise still from the new contactor and still even the light still dead  (i tested bulb its fine . i direct connected pump and it is fine running well on both speeds) i checked both air switches and they work. the 24h timer is only 6 month old and seems to react but could it be low current not strong enough to activate the contactor? when the timer gave up before it was pretty obvious at that time.
well that is what i know so far any suggestions be really appreciated and if needed give more info if someone points me  to what could be relevant.  thanks in advance.

well i did get no response but was helped in another forum 

but  i thought i add the problems reason to help others . the problem ,as it came to light, was a bad neutral connection  at the main breaker panel   which made everything go on and off intermittently and therefore hard to trace if there was something wrong within the hot tub.     that refreshed a valuable lesson to start at the basic in checking things and not to overthink stuff .

Edited March 18, 2019 by koby411
problem solved