cooling fans

[z28camaro94]

They do not come on ever.

I have gone throu this whole system and cant seem to figure out why there not coming on. With the key on, engine off i can jump the A and B terminals on the DLC, it energizes all the relays and the fans come on. So with that i know the fan motors work and the relays work. So after doin some research, I replaced both temp sensors( block and wp). The sensors still arnt having the fans some on.

Am I missing something? Is there anything else I can do to test this out.

Unfortunatly I cannot connect to the computer to see what the sensors are doing. Thats a nother problem in it self. I have to check continuity on the serial data line to the comp. I know on the comp the data line is connector D terminal 30, but which one is connector D?

Can anyone help please! I'm at wits end with this.



Oh and also the thermostat is the factory 180* and the comp is set at the factory setting for the fans(never could connect to change). If i could connect to the comp I would have them come on earlier.

[S.J.SLEEPER]

Ls? Lt? v6?
if you cannot get scanner to communicate with adl. you probly have a blown fuse. check all fuses, if all fuses good than check all your grounds.

[z28camaro94]

fuses are good. working on the grounds. car is in my sig, but its a lt1 w/4l60e


in the process of checking the wiring diagrams for witch grounds to go after

[S.J.SLEEPER]

dont want to say that its defintly the problem, but I have seen quite a few lt1 ecms go bad. And alot of their first symptoms were no data link.
Check all your grounds (body & engine) and also probe pos/neg wires @ back of the adl connector to make sure its not a bent/broken pin or wire.

[z28camaro94]

yea ive had the no connection problem for a while. but have had no drivability issues, other than the fans not working. im def gonna ohm out the data link today. i do have another new(reman) comp sitting in my room, just need to get the vin programed into it.
so at least if the data link ohms out like it should, then just pop the new one in and see what happens

[z28camaro94]

i just took the comp out and found the i have a Jet module piggy backed off the pcm. would that have any effect on anything

[bigz28man]

Are you getting voltage from PCM to the fans, this happened to me found out that the wire was severed between the PCM and the fan. Try there it may be your answer. It was a $5.00 fix for me.

[RamAir95TA]

http://shbox.com/1/4th_gen_tech2.html#cooling

[z28camaro94]

Originally Posted by bigz28man

Are you getting voltage from PCM to the fans, this happened to me found out that the wire was severed between the PCM and the fan. Try there it may be your answer. It was a $5.00 fix for me.

Yes. b/c when i jump the A and B terminals on the DLC they come on properly.


I'm gonna try disconecting the jet module today when i get home and see if i can read the comp. I would really like to see what the comp sees for the temp input. otherwise Im prob just gonna go with the fan switch.

thanks for the help guys