i have a 1990 5.0 tpi setup. no on my ecm d14 ltblue is the 4th gear switch wire that goes to the TCC solenoid. is it supposed to be open or closed in 4th gear?

my car is a standard now. and im try to figure out why my fan wont turn on at operating temp. d14 is hot atm, if its thinking its in 4th that maybe be the problem
my ecm is sending out battery voltage

heres a link to my ecm pinouts
might have to scroll down to 1990-92speed density
http://www.chevythunder.com/fuel%20injection%20ecm%20pinouts.htm#1986-89%20pinouts%20(ecm%20#1227165)

 

is their anyone on this board that understands the tcc solenoid?

 

The 4th gear switch and/or TCC solenoid doesn't have anything to do with the fan not working.

Your vehicle should have two fans, a primary and a secondary. One of them is ECM controlled, the other by a temperature switch in the head. The A/C will also kick one of them on. Forget which one though.

RBob.

 

my car has one fan, my new harness has wiring for two i have the primary plugged in. the primary is ecu controlled and the secondary is controlled by the switch in the head and the a/c also controls it...

if the primary shuts off in 4th gear like i hear it does, the way the ecm determines it is in fourth is through the 4th gear switch that happens in the tcc solenoid. this beening a swapped setup from a auto car into mine a manual i dont have a tcc solenoid... so thats where i am.

my ecm is suppling the primary relay with a ground however, its pulssing a ground to it. so i beleive something is telling it to not turn on. the next logical step in my head is the 4th gear switch.

i have the wire for the first gear switch i just dont no if its suppsoed to be open voltage or grounded... and im not bold enough to risk my ecm to figure it out