Conversion from Clutch-based Mechanical Fan to Electric

[DPDISXR4Ti]

I've never been a fan of clutch-based fans - one of the first projects I did on my '91 F-150 was converting to an electric fan - I used the dual-fan setup from a V6 Contour/Cougar/Mystique. And so I'm planning to do the same to the Scorpio, as time permits. No urgency, as the current one is working fine (Thanks Darren!)

Since I needed to do something with the upper radiator hose that was leaking from the vent, I decided to cut a section out of the hose and replace it with a T-fitting, as salvaged from a late-80's Saab 900. I've grabbed a couple of these over the years, for just such a retro-fit. As you can see, I've left the switch in it - for now it's just going along for the ride - eventually it would trigger the fan(s).

SaabFanSensor-1.JPG (970.21 KiB) Viewed 3908 times

SaabFanSensor-2.JPG (950.84 KiB) Viewed 3908 times

Slightly related topic... As I understand it, only the early cars got the failure-prone vented upper radiator hose. When the factory nixed that, did they change anything else from a plumbing perspective? I've seen different hose routings on later cars, but I'm not sure if that changed specifically as a result of the vent function delete or not.

[Ed Lijewski]

89s have the upper hose with bleeder tap.

Re other plumbing differrences, early 88s have piping from water pump around engine front to rear of engine and up to heater core. See pic. Lower coolant bottle hose feeds directly to water pump.


89s have the water pump port above blocked off w/rubber cap, and piping above is dropped. Lower coolant bottle hose runs down to and around edge of lower radiator, then feeding directly into a unique lower radiator hose.

YMMV

[Ed Lijewski]

Re radiator fan, IMNSHO, leave well enough alone. The fan clutches are good for 75K and more depending on lotsa severe weather use (hot, humid environments) or average weather variations usage.

Electric fans will draw amps. I've observed in both 88 and 89 fan clutched Scorpios that the electrical system just doesn't produce voltage at the battery as does the XR. On my XRs running with headlights and blower on high I consistently get voltage no lower than in mid 13s (14.4 with headlights and blower off) readings. Not so with the 88 and 89 Scorpios IME, where under the same current draws readings at idle are closer to 13.0 and occasionally a few points below that. And in each Scorpio the alternators/VRs were new remanned units, and in each the batteries were brand new and fully charged, and battery and accessory cable connections clean and in good condition.

I've repeated these test readings multiple times over multiple days with the same results.

Add to the above electric radiator fan draw, surely very often in hot/humid traffic, and a/c condensor fan draw in same conditions, and the stock charging system won't be able to keep up.

A 3G alternator retrofit, if feasible, might make the needed difference. Until then, leave well enough alone (and just keep an eye on engine temperature).

YMMV

[DPDISXR4Ti]

<I'm cutting and pasting this one back into this thread. Note that I've split the topic off regarding the "Alternate Alternator Upgrade" to it's own thread. Please continue that discussion there, and leave this one specifically related to the fan change. Thanks, Brad >
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Re: Conversion from Clutch-based Mechanical Fan to Electric
Post by Merkurfast » Tue Nov 27, 2018 2:20 pm

I wanted to put a Lincoln MkVIII fan in my Scorpio, but deduced the same thing. MkVIII fans are the best but might be more than you need to cool a Scorp and they are large. Some friends of mine used one of these fans to replace 2 aftermarket Spaal fans that caused his racecar to overheat. The MkVIII fan worked far better but draws amps. I concluded until I have a higher capacity alternator and a good fan controller, Im not going to install a electric fan.