budfreak1

iTrader: (7)

I just went out and installed my hypertech fan switch model 4026. When I kick on the ignition the pass. side fan kicks on and will not shut off until I unplug the fan switch or turn the ignition back off. Did I get a defective switch?

watajob

iTrader: (29)

Quite possibly. The Jet one I installed seems to be about 10* too low as it runs almost constantly after the engine warms up. 'Stat and gauge are verified good, too.

travis401

iTrader: (1)

pass side fan is the one that runs off the switch, so if the switch is bad itll either not work at all, or run the fan constantly with the ignition on.

deadbird

To add... the fan switch on a '91 should also trigger the primary fan via the A/C fan request (D12 ground) at the ECM. it, the fan switch, shares ground with the fan A/C pressure switch (line the runs the pass frame rail).

babadioum

No: see my post about that.

babadioum

True but WVE and Four Seasons brand switches, both claiming to be NO (Normally Open circuitry meaning fan is off) on description, are NC (Normally Closed circuitry meaning fan is on) and 2ndary fan is on when ignition is on. See my post for contradictory schematics about that right off the Service Manual, too. Since the probability of me getting defective switches fro two different brands are minimal, the natural assumption is that both are being manufactured NC circuitry to be used in hot climates. I understand that it is possible for both to be lemons, but hey, until someone who bought either brand during 2022 and claims it to be working w/ NO ops, I am not buying a new one: instead I will install a manual switch to 2nd fan relay and place under the dash, while keeping the the socket off from Nov to Apr and switching it on when necessary during A/C on hot for fog, snow, etc., and have it plugged on keeping the 2nd fan on at all times from May to Oct. Simple solutions for discontinued parts whose knock offs are garbage. Another option can be to find a switch w/ NO and similar operational pressures between 185-230ish psi and same threads and put that one in.
PS: The 1st will also come on when A/C is on that proves ECM and ground circuitry is good. Further, while switch is uninstalled, plugging it to the socket will kick in the 2nd fan that proves the switch is manufactured as N.C. (normally closed with fan on) as it grounds the circuitry.

Tuned Performance

iTrader: (92)

@RBob could another work around be change no to n/c in $8d
then rewire the secondary fan relay switch to relay ?

RBob

iTrader: (1)

This is an old thread, but here is babadioum's recent thread about the wrong TPI A/C pressure fan switch being listed/sold:

https://www.thirdgen.org/forums/elec...-pressure.html

As for the cylinder head temperature switch the OP is having issues with. It is likely bad. Should be open until the engine is up to temperature, then close to turn on the fan via the relay.

RBob.

Tuned Performance

iTrader: (92)

Ugh the scroll down got me

RBob

iTrader: (1)

It can be disabled in your user CP. Can't recall how, but is a switch/flag/button/check. Did it shortly after that 'feature' was put into place...

RBob.

Tuned Performance

iTrader: (92)

Thanks I didn’t know it was an option. Disable infinite scroll

babadioum

Short of it from a VERY long issue: The ONLY part for this is Four Seasons 36666 which is NOT an OEM replacement, but as I suggested above, a simile that should do the job. 36669 which is sold accross the board in all sellers as an OEM replacement is manufactured as NC, specs stickered ON the switch literally proving that NC operation, yet the info sheet claiming otherwise.

I literally struggled the entire 12 months plus to get to the bottom of this; WVE--the manufacturer from whom I purchased the part initially--has accepted readily that theirs is not ours and is mislabeled. Four Seasons--the manufacturer I purchased the part from TWICE to make sure that first is not a lemon, a statistical verity in the realm of possibility--was VERY evasive, have NOT accepted per se the mislabeling even after a ton of video proof of the testing process, but at long last advised me to use 36666 instead that carries similar specs and NO per my multimeter test (dial does not move and stays at infinite).

As for the sellers, I am losing my faith in humanity, perhaps through gen Z(ort!): Rock Auto went so far as to claim that "no one had an issue w/ this part" kind of nonsense, instead of shutting up, thanking me for pro bono consulting I provided to them that should have been their job after my complaint and a plethora of video proof through testing w/ a multimeter, and doing their proper job at their headquarters which should have been to call Four Seasons higher-ups and sort this out since a) WVE (the only other company w/ that part) already admitted the mislabeling and RA were directly made aware, b) science trumps bullshit at all times, but alas!

gfrank

Question of clarification on the secondary fan. It operates based on AC on OR temp over 238, correct? Or is it an AND statement, meaning both conditions must be met?

Tuned Performance

iTrader: (92)

Turns on a/c request or fan temp switch grounded