87 TPI single fan wiring
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From: Hawaii
Car: 89' Firebird / 87' Formula
Engine: 3.4 / 5.0
Transmission: 700-R4
Axle/Gears: 3.42 / 3.42
87 TPI single fan wiring
Just wanted to share this but....
After years of thinking that my single fan was operated by the fan switch.... I found out yesterday after cleaning up some wiring, that my 87 305 TPI with a SINGLE fan has the fan switch in the head.. it also has the connector / the wiring.... but apparently that wiring does not go anywhere.... it doesn't connect to anything. It connects to the electrical connector by the radiator that goes to the fan, but on the opposite end of the connector, there is no pin at all, and is actually plugged off.....so it's a dead connector from the factory. So it seems that these 87s came pre wired, fan switch and all for a dual fan setup / option and the single fan is controlled by the ECM. If i recall correctly. dual fan TPIs have one fan controlled by the ECM, and the other by the switch in the head.
Not sure if this is already known but I came across a lot of threads in the past saying all single fans (carb,/ TBI / TPI) are controlled by a fan switch aside from single fan 85 / 86 TPIs. In 85 / 86 I think they only had plugs in the head....In 87 I guess the single fan was still ECM controlled but they pre wired everything and threw in a fan switch in case a dual fan option was ordered.
This might explain a lot of threads where people have a non working fan, they change the switch and the fan still...doen;t work. Its because the shingle fan was ECM controlled.
After years of thinking that my single fan was operated by the fan switch.... I found out yesterday after cleaning up some wiring, that my 87 305 TPI with a SINGLE fan has the fan switch in the head.. it also has the connector / the wiring.... but apparently that wiring does not go anywhere.... it doesn't connect to anything. It connects to the electrical connector by the radiator that goes to the fan, but on the opposite end of the connector, there is no pin at all, and is actually plugged off.....so it's a dead connector from the factory. So it seems that these 87s came pre wired, fan switch and all for a dual fan setup / option and the single fan is controlled by the ECM. If i recall correctly. dual fan TPIs have one fan controlled by the ECM, and the other by the switch in the head.
Not sure if this is already known but I came across a lot of threads in the past saying all single fans (carb,/ TBI / TPI) are controlled by a fan switch aside from single fan 85 / 86 TPIs. In 85 / 86 I think they only had plugs in the head....In 87 I guess the single fan was still ECM controlled but they pre wired everything and threw in a fan switch in case a dual fan option was ordered.
This might explain a lot of threads where people have a non working fan, they change the switch and the fan still...doen;t work. Its because the shingle fan was ECM controlled.
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