Since day one, it always seemed to kick the fan on when the gauge was almost pegged, and I hated that. Seemed like it should come on sooner.
Now it seems to have quit working completely. I put in a used one I had laying around, and it works, but same problem, kicks on when almost pegged.
The OEM part number for 80-86 looks like it was E0ZZ-8B607-A. But I see there is an E7ZZ-8B607-A that fits 87-93 5.0 Mustangs and it looks identical to the E0ZZ.
Maybe it would come on sooner? That would be great. Does anyone have any knowledge about the later switch? I don't want to operate a manual switch for all you guys that fool around like that.
thanks, Jim
06-19-2025, 07:29 PM
(This post was last modified: 06-19-2025, 07:42 PM by
TurboRay.)
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AFAIK, there were/are two different strategies for Lima electric-fan "turn-on". The early ones used direct control, via a single-pin sensor & relay, whereas fans on the later cars used a multi-pin sensor that signalled the ECM to turn it on (also, via a relay). As for WHAT the sensor temp thresholds are....... I wouldn't begin to know where those specs could be found. Perhaps our resident Ford electronics guru, dan_xr4, would know? DUNNO!
If yours has a single-pin sensor, you may be able to substitute it for an aftermarket version with a (published) lower temp threshold, like those available from the various electric-fan suppliers, such as Flex-a-Lite, Spal, etc.. OTOH, if your fan is computer-controlled (via the multi-pin ECT sensor located at top/center of the intake manifold), you could switch to analog control by installing a separate/aftermarket single-pin sensor and relay, like the 1st-gen OEM & aftermarket system(s). <shrug>
Placerville, California
(former) '78 2.3T Courier w/blow-thru Autolite 2bbl carb ~ (current) '87 2.3T Ranger w/PiMP’d EFI
06-20-2025, 04:06 AM
(This post was last modified: 06-20-2025, 04:46 PM by
dan_xr4.)
The cooling fan switch should be a 3/8-18 NPTF thread. The older Turbo Fords (1983-1985) have the single terminal switch. As TurboRay suggested the single terminal switch can be replaced by many different aftermarket switches.
The original (1983-1985) switch is designed to turn the fan on at 220 degF and turn the fan off at 200 degF. This switch is designed to run the fan only when the coolant is pretty hot. This keeps the fan from running when the coolant is in its normal operating range.
Most of the aftermarket switches run the cooling fan at lower temperatures. The problem with running at lower temperatures is that the fans might run a lot when the coolant is actually in normal operating range. Some aftermarket switches on the Summit Racing site turn the cooling fan on at as low as 180 degF and off at 165 degF. One of the higher temperature switches available is on at 210 degF and off at 190 degF.
The 1987-1988 Turbo Coupe went to a low speed fan and a high speed fan. The low speed fan goes on at 200 degF and off at 190 degF. The high speed fan goes on at 220 degF and off based on time and temperature.
On my Mercury, I've got an aftermarket switch that is on at ~205* and off at 180*.
The TBird is controlled via MegaSquirt and I have the settings about the same as above.
"Nobody can be so amusingly arrogant as a young man who has just discovered an old idea and thinks it is his own."
1983 TBird TC Clone - 1985 Mercury Marquis LTS - 1986 LTD Wagon - 1981 Granada GL 2DR
The aftermarket one that turns on at 205 and goes off at 180 sounds good. What is the brand/part number for that one?
I did take out the original 197 thermostat and put in a 180. So that may be perfect.
Thanks, Jim
Had to dig up the order. (From 3 years ago)
Looks like I got it from Summit.
HERE
"Nobody can be so amusingly arrogant as a young man who has just discovered an old idea and thinks it is his own."
1983 TBird TC Clone - 1985 Mercury Marquis LTS - 1986 LTD Wagon - 1981 Granada GL 2DR
