Ive gone through the facts and most posts on this subject.Cant find what im lookin for.My problem is that my fan wont come on when the motor gets up to temp.I have a new fan switch,relay and fuses.The relay has power and the fan comes on if I ground the relay out.I read that the dark blue wire was the fan switch wire.People said to ground it to the frame to see if the fan comes on with the key on.It doesnt come on.Whats that mean.I know I need a new pigtail.But why will my fan not come on when I ground that wire??That wire sends a ground signal to the ecu right??I ohmed it out and I had 2.00Kohms Is that bad??I need to get my fan to come on when its suppose to instead of the way I have it now where it comes on when you turn the key on.I also have a 180 thermostat.Any help would be appreciated.Thanks

 

86Z, yes ground the wire from the fan switch. It should be on the passenger side between 6&8 cylinders, above starter, if I remember correctly. The ignition switch needs to be in the run position for it to work. If the fan comes on everything in the system should be ok, replace the fan switch if it is not working. Not sure about your other questions, you may want to use the "search" function at the top of the page if no one helps you out.

 

Yeah I searched everywhere.Well I took that wire and ground it to the frame with the key on and nothing happpend.Does that mean the wire is bad??Or is there something wrong with my ecu??It worked fine before I swaped engines.I dont know what could have happened in between then and now??LOL

 

86Z, pm me your e-mail address and I will attempt to send you the wiring diagram for your car, there will be 2 or 3. I am not up on ecu`s so I can`t answer your question. You should be able to install a manual switch to run your fan until you figure out what is happening. I can`t access your car specs from here so also pm me with the year and engine size along with your e-mail address.

 

86Z, I looked at the wiring diagrams for your car and found a fusible link on an orange wire that runs to/from your fan relay, you may want to check that out.

 

My relay has power to both wires going into the relay.Right now I have the fan were it comes on with the key.The fan works.If I ground the relay using the wire that the ecu is suppose to ground it comes on so I know the relay is good.But the ecu never grounds the wire.It doesnt turn the fan on when I ground the fan switch with the key on.Ive been looking for wiring diagrams all day.Do you know which pin# it is on the ecu plug for the fan switch wire.Then I can isolate it to see if theres something wrong with the wire.Is there any other fan relay on a 86 305 tpi other then the one by the battery??Thanks for the help.