97 w900l

I have a problem with a w900l
When the truck is running I can turn on all the lights no problem however when I have the lights on and turn on the blower in the front on within a few seconds the truck will start shuting down and lose all power
Just run lights no problem
Just have the blower no problem

 

That's my next step I have check the wiring harness through the fire wall no corrosion it's a over load on a circuit just need to trace it down hoping some one can point me in the direction I have not thought of thanks

 

The engine is a 3406e I have check the voltage drop at the alternator had no drop in voltage when truck starts to shut down
When the blower and light are on
And the truck starts to shut down I can turn off lights or the blower and it will regain power and run fine have no problem when just running lights or blower buy themselves only starts to shut down when both are being used

 

No not at starter battery's check yes