ls1 automatic electric fan switch / relay
ls1 automatic electric fan switch / relay Hey guys,
98 Trans am ws6, a4
I was looking into the manual fan switch idea as my pcm is not turning the fans on at all. The car has been tuned by a reputable tuner by the p/o...but I am finding some fishy stuff lol.
Anyway, as I would like to actually be able to drive the car at a decent temperature I need the fans to work. I could deal with the manual switch but I figure my wife will drive the car on a rare occasion and I also wouldn't want to have to worry about flipping the switch off.
I am contemplating using a relay to send ground to the fans to have them both running all the time the key is on. Would probably use the fuel pump or radio as a trigger...
What my main question would be is would it hurt anything to have the fans run all the time? I will put a "hidden" switch in the "trigger" wire that I can control manually so I can turn the fans off during winter if need be...
I would wire relay like this:
30 and 85 to ground
87 to blue fan wire from pcm
86 will be coming from my "trigger" to turn the relay on
So, in other words I will have both fans on all the time with the option of turning them off via a switch...
98 Trans am ws6, a4
I was looking into the manual fan switch idea as my pcm is not turning the fans on at all. The car has been tuned by a reputable tuner by the p/o...but I am finding some fishy stuff lol.
Anyway, as I would like to actually be able to drive the car at a decent temperature I need the fans to work. I could deal with the manual switch but I figure my wife will drive the car on a rare occasion and I also wouldn't want to have to worry about flipping the switch off.
I am contemplating using a relay to send ground to the fans to have them both running all the time the key is on. Would probably use the fuel pump or radio as a trigger...
What my main question would be is would it hurt anything to have the fans run all the time? I will put a "hidden" switch in the "trigger" wire that I can control manually so I can turn the fans off during winter if need be...
I would wire relay like this:
30 and 85 to ground
87 to blue fan wire from pcm
86 will be coming from my "trigger" to turn the relay on
So, in other words I will have both fans on all the time with the option of turning them off via a switch...
it will work but there are some very cheap standalone fan kits you can use. You get the relay, sender and necessary wires with it. Then you can wire it to run off the sender or bypass the sender with your switch to turn them on. Check out summit or even ebay. Should be around 30$
My fans run low speed full time pretty much (on at
just below thermostat setpoint). They seem fine and
have not gotten noisy or anything.
I've got some encapsulated electric thermostats
epoxied to the new radiator for "someday" converting
to a tank-temp-controlled fan scheme and eliminating
the PCM's involvement. This is a couple of bucks for
those, and you'd need a couple of relays or to re-
deploy the current ones and rewire their coils to be
driven by the thermostats.
just below thermostat setpoint). They seem fine and
have not gotten noisy or anything.
I've got some encapsulated electric thermostats
epoxied to the new radiator for "someday" converting
to a tank-temp-controlled fan scheme and eliminating
the PCM's involvement. This is a couple of bucks for
those, and you'd need a couple of relays or to re-
deploy the current ones and rewire their coils to be
driven by the thermostats.
Went by today and picked up a relay and a switch / wiring connectors. Already had the wire so it will be about $15 for the system...will post up results hopefully Friday when I can get it all installed. Still on the wall as to whether I want just one or both fans running all the time. Gonna do a radiator flush and new thermostat also. Do I need a thermostat housing gasket or anything? Thanks
Got the fans working all the time. Took about an hour. Ended up running a wire inside to the radio fuse to turn on the relay. But, turn the key on and the fans come on. Key off, they shut off 
Alot happier with this than having to remember to shut them off manually lol... Next is a good radiator flush and new thermostat
Alot happier with this than having to remember to shut them off manually lol... Next is a good radiator flush and new thermostat The actual problem ended up being the temp sender sending a bad reading to my gauge...run right under 180 at all times now Now to get this idle issue fixed and I will be a happy camper!!!
Now to get this idle issue fixed and I will be a happy camper!!! 
