The right hand fan should always have 12v on pin 2. However, it is switched on by getting a ground signal from the fan relay module. The other fan is the opposite, ground always connected and 12v switched to turn it on. The relay module then connects them in series or in parallel in order to control speed.

 

If I may be allowed to complete the thought......


....according to signal(s) from the radiator thermo switch or the a/c pressure switches.

Cheers
DD

 

Yep, right you are Doug

 

Ok the ring in the tank is there. I was looking for a white ring but it's black and it's not stuck. I just put almost a whole gallon of premixed coolant in the tank and then went for a test drive. When I got back I looked underneath and sure enough it's leaking. It's coming from somewhere near the top of the engine but I can't tell where. You can see that it sprayed the top of the valve cover and it's on the hood liner or whatever it's called.

I hate it when you fix something and something else just happens to break!!

Pics to follow.

 

My bad. When I said "low coolant sensor" I had it confused with the thermo switch, down low, left side radiator side tank. I was fishing for a way to get low-coolant caution light, but normal coolant level, and overheating - and a cause that would tie it to your balancer change and/or coolant/T-stat R&R. Got all excited and renamed the thermo switch as the low-coolant sensor. I guess not everyone pulls the radiator to change the balancer, but I did. If all you pulled was the fan module, you may not have needed to unplug the thermo-switch.

From one of your recent posts, it sounds like maybe coolant actually is low - which could account for the overheating - but your fans should still be on. There is no "bleed" port on these, as earlier models had, but I did all of that and more this past summer, drain/flush/fill all done with front wheels on ramps and had no problems with trapped air - and was also sitting "drained" for about 6 weeks and didn't get a sticky float.

You can "flush" with water - though it would've been quicker back when your t-stat was stuck open. Like you did before, drain at draincock or lower hose, top up, run (long enough to come to operating temp if you are doing it with a functional t-stat installed) drain, refill, repeat til you get clear water. (A large plastic busboy tub works well as a catch-basin)
I, personally would shy away from using a flush compound, though others may not. I did use distilled, but my tap is a well with some pretty hard water (45 gr!) and although softened, I was leery of the sodium content from the softener - distilled available at WallyWerld for about $0.85/gal. I believe I went thru 12 gal to flush my green coolant to the point I was satisfied calling the water clear. I did use tap-water to flush the heater core b/c I wanted some press/flow available from the garden hose, but I followed that with a couple of gal of distilled just thru the htr core.
If you do use a flushing compound, make sure you flush enough water behind it to get it all flush solution out.

A number of years ago, I topped up the 2003 S-type ("Pink" coolant) with Prestone's Green "mix with any all coolants" after a radiator hose change and ran it for probably a year or so til Motorcarman caught me with it ("Yer radiator had some kinda funky coolant in it...so I flushed it out and put the proper stuff back in") - during a balancer change, no less... and as far I know, it is no worse for the wear. (Still very glad he set me aright, though) If the two are of the non-mixing kind, it forms a kind of sludge or jell that clogs up the small passages in your heat exchangers. In the end, it really matters what the two coolants are, moreso than the color.

 

 

 

Colour is less important than specific chemical composition. There are basically three major classes of ethylene glycol coolant, IAT (inorganic acid technology), OAT (organic acid technology), HOAT (hybrid organic acid technology). They shouldn't be mixed.

IAT is the old green stuff, containing silicates which are the anti-oxidant compounds that keep your cooling system from rusting. Works great, no issues, but the silicates are depleted in about 2 years, possibly 3, so the recommendation is to change coolant every 2 years.

OAT uses organic acids to prolong the anti-oxidant ability of the coolant. These form a molecular layer on contacted metal which is how they inhibit corrosion, and it takes about 5000 miles for this reaction to fully occur. Silicates in IAT coolant react immediately but are rapidly consumed (a buffered pH solution, back to high school chemistry). OAT coolants are supposed to last 5 years. The first one was GM's Dex-Cool. The major neg of this is one of the chemicals, 2-EHA that acts as a plasticizer and weakens certain plastic cooling system components. It also is prone to rust in certain engines that don't have the coolant changed often enough, mostly iron blocks and ones that expose coolant to air more than most. I had a 94 GMC Yukon with the 5.7 V-8 that rusted up with factory recommended coolant changes. Our Jag's don't have as much iron as aluminium so it should be less of an issue.

HOAT coolant is a hybrid of both. Mercedes and Chrysler are the main users of this. IMO HOAT is the best of both worlds. But, it seems most vehicle manufacturers are moving to slightly different versions of OAT coolants for long life/less maintenance/make the the customer happy reasons, plus making environmentalists happier by less ethylene glycol being used/dumped/needing to be recycled.

Most "universal coolants" are OAT, though some don't have 2-ethylhexanoic acid (2-EHA) in them.

The major reason to not mix coolants is due to additive incompatibilities which can cause precipitation and plugging of coolant passages. Adding IAT to either OAT or HOAT reduces the life of the mixture to that of IAT, defeating the purpose of long-life coolants.

So, nothing wrong with using IAT coolant, just change it every 2 years. Universal long-life coolants are OK, but preferably ones without 2-EHA, though the AJ16 engine isn't overly at risk. My preference is for HOAT. Zerex G-05 is the aftermarket version of this, though Chrysler brand coolant is the same.

Valvoline.com > Products > Zerex > Antifreeze Zerex > Zerex G-05® Antifreeze / Coolant

 

Wow! Thank you for that very informative post!

 

I'm thinking it may be leaking from this line (in yellow) but it's pretty hard to tell. Any other ideas?

 

Yes sir, the float on the inside of the expansion tank can stick down after a drain, which keeps that light activated. The float can barely be seen inside the filler cap, it is a white donut, that when floating will keep the coolant light off. You can free it up by carefully prying with a stiff wire and flashlight. If you aren't losing coolant, this is most likely the scenario. I've seen it three times on my own vehicles. The sensor itself is actually outside of the tank but has a probe that this donut on the inside of the tank activates. Obviously a very important telltale that you want to work correctly

 

JVITEZ: Thank you for the most intelligent and comprehensive explanation of coolants I have seen to date. Excellent stuff.

Mike