Photosteve

I have a 1985 euro and the previous owner installed a nice new radiator and twin electric fans. The fan controller died and rather replace it with another digital one I’d prefer an analog solution. Looking at the bottom of the radiator I see there’s a fan switch, would it be feasible to wire a relay to this and use it to switch the fans? Is the temp setting suitable?

the second question is related to the rear end trim. My tabs holding my spoiler on are all corroded and I’ve always liked the shape of the early cars so I’ve decided to remove it.
On the rear quarter windows, do I have to replace all of the trim or just the rearmost parts? Also can I just change the trim on the rear hatch or is there more to it than that?

thanks for any advice!

gazfish

The normal setup is a clutch fan doing most of the cooling and an electric push fan when it’s needed, that fan switch only operates when the temp gets too high for the big fan to keep up since the switch is at the coolest part of the radiator. Swapping it for a lower temp switch might work but personally I’d get one of the kits that attaches to the big hot hose at the top or change to the original setup. Either way your fans will now run at zero or 100% which isnt ideal, it’s more binary than analogue.

The rear quarter window trim is different but also the window rubber as an extra piece follows the trim over the top of the spoiler, don’t know if this can just be cut back but replacing the trim with the rubber/glass in place is a pain.

Petza914

I just removed my wires from that lower radiator switch and ran a separate switch with relay to them into the cockpit so I have full manual control of the front mounted fan. Power is fed to the relay from the original fan wire and the switch inside supplies the 12v trigger voltage when pressed.


Push button switch mounted in ashtray next to dual USB charging ports with voltage gauge and remote USB stick for stereo MP3s



Ashtray door hides it all



SPDT relay that drives the fan



Relay is mounted with neodymium magnet



Looks stock



Top view of mounted relay

The Forgotten On

I would definitely stick in a new digital controller.

The relay may work, but it will have huge current spikes which will not be kind to the other electronics in the car and could even cause it to stall when the fans activate.

If all else fails you could buy a dual stage fan relay setup similar to an older Lincoln MKVIII and have a low and high similar to how the later 928 S4s operated, but it still isn't as good as a real fan controller.

Photosteve

Petza914 That’s a good idea being able to override the fan from the cabin. Where did you bring the wiring through the firewall?

gazfish good point about the switch being the wrong end of the radiator. I think I’ll pick up one of those kits you mentioned.

regarding the trim, does anyone know how it is attached to the rear hatch on early cars? I’m assuming it doesn’t use the same mounts as the spoiler?