As part of my big cooling system overhaul I'm doing to my '88 5.3, I was thinking of fitting my own fan switch.

I know of the 2-pin overheat switch threaded into the front of the water pump area, but the connectors on mine are all messed up from a previous owner, and I'm not even sure if it works (or what temp it's supposed to turn on, since I've never had it turn on in normal operation).

With that being said, I'm thinking the easiest solution to this would be to fit my own fan switch into the water rails, as there are two vacuum valves/solenoids/? already threaded in (pics below)

B-Bank Front, IIRC part of the original charcoal canister/evap system

A-Bank Rear

Would anyone happen to know what threads these are? Ideally I'd like to order a switch with the correct threads or find an adapter, as I've already got the intakes back on w/ fresh gaskets, so I really don't want to go through the trouble of tapping them.

When doing so, what temp switch do you guys think I should go for? I'm swapping to 180F (82C) thermostats, and it's getting an aluminum rad... Maybe 190F on? 195F on?

Also, as I'm switching to the 4-row rad, and finally getting a black fan to replace the old yellow fan of doom... Thoughts on swapping to a new fan clutch? I have no idea if mine works properly.... I saw some posts on Jag-Lovers about some Severe-Duty options (Hayden 2747HD or 2797?)... The noise doesn't bother me, I'd like to err on the side of caution and pull more air if I'm going to have to pull it out and replace it anyway.

 

I have little to say on this, coz the more I say, the more trouble I get into.

ALL cars, and I mean ALL cars in OZ, have ANY thermo fan switch in the cooler side of the radiator, AKA the Lower Hose, or close to. That is because the Cooler side is more stable than the Hot side. Too many years in the trade, not typing all that here.

The Jag OE switch is 85C Down Here. Other markets, NO IDEA.

Fan clutch, YES, and there is NOTHING wrong with OE spec, its 40 plus years old, and done well, as in 1982ish intro of the HE.

ALL my V12 run twin Efans, and they would be more than 30 years old, and no issues, even in peak traffic in plus40c temps, AND, I run the OE radiator.
Fans wired, LH is AC Only, RH is Thermo Only, using that OE switch to activate that relay, to activate that fan, simple.
With the AC On, the Thermo fan has NEVER activated. The Jag system is that GOOD, once Freddy Fidler is extracted.

NO idea on those treads, never ventured there, as mostly those ports were blanked off, not threaded, in our market.

 

The image shown is odd - that is in the coolant distribution rail bank B thermostat housing that runs on the head, that is used only for the ECU in the car - they should be spade terminals. The sensor that the instrument in the car uses is on bank A, there is then a stat type switch in the return to the water pump. The threads are different bank A and bank B, bank A is 5/8” UNF, 18 tpi, bank B is metric 12mm x 1.5mm thread.

Ditch the mechanical fan totally - go electric for both fans. I introduced a split range thermostatic switch in the radiator return each channel of which I use as 'last resort' to run the fans - I will try to dig out the part number as it escapes me at the moment

The dual switch for the fans is from a company called FAE - part number 318-5BC-D95, I believe that they do a number of ranges. I do not use this to enable my fans as I use PWM for both based on temp sensors, I do however use the circuits from this switch as an 'emergency backup' mode that I can use should my controller take a dump.

 

Quote:

Thoughts on swapping to a new fan clutch? I have no idea if mine works properly.

When it doubt, change it out!

Get the engine up to operating temperature or, ideally, a bit hotter. Turn off the engine. Give the fan a spin with your hand. It should turn less than one revolution. More than one revolution and it is faulty, or at least suspect, and should be changed.

Cheers
DD

 

Not odd, really. My V12s had the same switches. Jaguar had a variety of different devices in use ....or NOT in use....depending on model year and market.

Cheers
DD

 

I think the easiest thing...if that's your true objective.... would be simply installing a new original type switch.

But the e-fan circuit on your '88 should be wired into the a/c compressor circuit. And the compressor circuit is alive whenever the climate control is in use, even in heating mode. So, realistically, and by design, the e-fan will normally be running whenever the climate control system is being used. For most of us that would be 100% of the time. This makes a temperature control for the e-fan useful only if the climate control is switched "off".

Just something to think about.

Cheers
DD

 

I'll be honest, I didn't realize the OEM fan switches were that reasonably priced, I just had a look around... I will probably go that route now that I know. Looks like EAC2510 should be 92C on, 82C off, perfect for what I want.

Interesting note about the climate circuit, I knew about it being tied into the AC compressor circuit (for obvious reasons), but didn't know it was supposed to come on when the HVAC system was in use in general. Mine has never turned on, and my AC system has been inop for probably the past 3 decades or so (it's the last thing on the list after this big cooling/ignition system overhaul). No clue on the heater functionality either, it only gets taken out in fair weather, being an H&E Convertible... So I've never attempted to use it.

 

I suppose I may as well go ahead and buy one then. My car isn't exactly running right now (as evidenced by the other thread with the distributor debacle). Just will have to do some research into which one to buy... Leaning towards the Hayden 2947 as it should give me a little more clearance, my new 4-row rad is no doubt thicker than the OEM rad.

Current plan of attack is:

1. Install new heater hoses while the fuel rail is out and access is better
2. install new distributor cap+rotor and fuel rail
3. Get it up to temp and flush out whatever nastiness is in the block while I have the original rad in so no junk gets sent through the new one.
4. Remove rad, install new clutch, blades, thermostats, rad, and switch in one go while the old rad is out and access is ideal