Here is a wiring diagram of how you should by-pass that cooling fan by using a toggle switch, and you can get a fuse holder and use a 30 amp fuse instead of a 30 amp circuit breaker, but you should use the circuit breaker since you are no longer using a relay, and if there is a voltage spike the circuit breaker will reset itself, and a fuse will blow out and you will have to change it. Most auto parts stores will carry the 30 amp toggle switch and circuit breaker, also be sure to use 10 ga. wire and do not forget the wire connectors that you will need to attach the wires to the toggle switch, the circuit breaker, and to the battery as well as the connection to the cooling fan wires.
This wiring diagram is very basic and you should be able to follow it with little difficulty, and you should also dis-connect the cooling fan at the wiring connector to the cooling fan and connect the by-pass wiring directly to the cooling fan motor so that you do not run voltage back through the stock system. Let me know if you require further assistance.
What's missing when it dies ? Fuel , spark ? Why even mention closed loop , that has no bearing on it . When the vehicle get's hot ,a sensor is shorting out internally causing it to die. Then when it cools down it starts again, correct ? Pull plug wires off one of the coils an turn the key to start , do you see spark ? Put a fuel pressure gauge on the vehicle an see if there is pressure . Or find yourself a guy like this
How to test GM 3 wire crank sensor hall effect type
If it was running good before, you probably lost spark or gas to the engine. If you spray a little starting fluid into the throttle intake and the engine starts briefly from that, then you know it was a fueling problem. Check the fuel pump and fuel filter, or do a fuel pressure test. If no fuel pressure at the engine's fuel rail, you would need to check the fuel pump circuit before condemning the fuel pump.
If spraying starting fluid doesn't do anything, then it may be a spark (ignition) problem. Check for spark from a spark plug wire with the engine cranking. If no spark, suspect a bad Ignition Control Module, or the crank or cam position sensors, possibly a bad ignition coil, or as a last resort a bad PCM, but such is rarely the problem.
It's kind of a long shot, but there may be a trouble code that indicates the problem. Get any possible trouble codes to flash out from the check engine light, by using a paper clip at the diagnostic link connector. Here is how: http://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method
Should be just below the water pump. Look on the passenger side of the front of the engine. You should see some wires connected just below the water pump.
Vacuum leak or manifold absolute pressure sensor is faulty. As rpm's increase, manifold requires more vacuum to pull fuel into the intake. If there's a leak or a bad sensor, fuel can't get to the cylinders fast enough and the engine starves and dies. Check and repair any vacuum lines and intake gaskets that leak..
