Don’t get me wrong, having the rad. fan on all the time can’t really hurt anything but the fan, [it wasn’t meant to run continually] although doing so has not hurt yours for two years
I should also have said the other reason for rewiring the fan would be if there was a problem with the oem wiring.
That said, and what appears to be the only problem, forgetting the switch on or off, or what is on or off [from what I am hearing] why not skip the switch completely?
Even if you bypass the “Rad fan Relay” and the “Coolant Temperature Switch” and all the oem wiring, [pos. (+) and neg. (-)] you could install a relay by the rad. fan, run a 15A fused line to the rad. fans, [blue/black] wire, [if there was something wrong with the oem power wire (15A fused white) wire] connect a ground to pins 30 and 85, connect the rad. fans, [blue] wire to pin 87, and run a fused 1A, [could even be a .5A] line from the 2nd ign. free pin on the fuse box to pin 86 of relay, that way the rad. fan would always be on if ign. is in the run position, [motor running] and could never be forgotten on. :idea:94
sounds good… are you good at drawing schematics? maybe you can draw that up, so people who have problems can if they want, wire it up that way. if not, i’ll attempt to draw again… hehe
Sorry I am a computer no0b, and would have to have my niece here to walk me through it, [not the drawing of the schematic, posting it on the tread] but this may or may not help http://sonolithics.com/files/bosch.pdf a lot of things you can do with relays :idea: 94
I had a problem with my fans not kicking on so here is what i did with my 92. I grounded the fan with a wire to the chassis. I then ran a wire from the fan on the power side (using connectors fo course) to my cruis control switch found the constint power and spliced into it. It comes on when the ignition is on, the cruise control doesnt have to be on to work, and the wire never gets hot and never melts anything but thats my .02. It has been working like this for at least two months now and was extremly easy to do
regarding the radiator fan switch on the back of the block on a 90-91 (as the same as the radiator fan switch on the thermostat sensor on 92-93)
along with my fused relay setup i have right now for my radiator fan which is ran by a switch in the cabin running a signal to the relay by a 12v power source to turn the fan on, im trying to find a better way to do this, so that the fan does not always stay on, but only comes on when needed…
i was thinking about using the radiator fan switch to work as the switch instead of me manually using a switch in the cabin…
what im thinking is, instead of using a switch to turn on/off power to the relay, can i run power to the relay constantly (as if the switch were left to the on position) and the ground that the relay needs, run that wire to the radiator fan switch, and other end of that to a chassis/engine ground?
would that work? is there anything i should be worried about? currently, the relay is bolted down by a 10mm bolt on the intake manifold above the alternator. and i already extended the wires for the radiator fan switch, so i can tap into them easily.
Kind of like the oem system, the “Engine Coolant Temperature Switch”, [fan switch] supplies a ground to the “Radiator Fan Relay”, [low current] the “RFR” then in turn supplies a ground, [high current] to the “Radiator Fan Motor” that has a constant 12V, [hot at all times] going to it.
The diff. would be, in the oem system the “ECTS”, [fan switch] controls the relay that supplies a ground to the fan, you want to do the same thing but supply 12V (+) instead of the ground :hmm:
PS… yes it would work, but if the problem is that the fan does not have 12V (+) at it, why not just fix that?
i’ve already cut or am now missing wiring for the fan system, and already have it hooked up like this, minus the radiator fan switch. oh, so if i leave everything the way it is now, but run the ground wire from the fan to the switch, and ground the other, and leave the cabin switched to the “on” position. it would work…
do you think i would have any problems running a 16 gauge wire from the radiator fan to the radiator fan switch on the back of the block? or does that problem with running long wires with power burning up only apply to wires that have 12v running through it?
You can’t use the “ECTS”, [fan switch] as a ground for the fan, if you are missing wires then rewire, if you do not have power at the fan on the blue/black wire that is connected to the white wire, [12V (+) fused at fuse 12 15A (hot at all times] in under dash fuse box] then run a 15A fused line from batt. to fans blue black wire, then, [also if missing] run a wire from the blue wire on fan to the blue wire on fan relay, make sure black wire on relay is grounded, connect the yellow green from the “ECTS” to the yellow/green of the fan relay and connect a switched 12V (+) to the black/yellow of the fan switch, if the fan relay is N/G replace it with a SPST or SPDT relay, pin 85 is black/yellow, switched 12V (+) pin 86 is yellow/green from “ECTS” pin 30 is blue, ground for fan, and pin 87 is ground.
