Coolant woes...

[Scott87]

She was running a bit hot for my liking...  200 to 220 stuck in traffic..

Fan wasn't running decided replace both relays and delay relay...  Fixed the delay relay,  fan wasn't running under drive conditions...

But the fan now runs when hot when keyoff due to new delay relay..  So that at least functions as it should...

Bought gn1 radiator and dual fan,... 
Did more research found Mr.  Woods section on coolant sensor and ac compressor high pressure switch...

Ordered a new fan sensor switch installed still no fans under running condition...

Disconnected ac high pressure switch..  No fans,  jumping around high low relays, no go...

So tried settings my extender chip to race mode...  No fans..

Pulled high fan relay,  put a jumper wire across fans screaming and temp drops 200 ish to 160 in no time...

So delay relay is working as it should,  but fans under running condition are no go.


My ecu looks clean just installed logger didn't see any corrosion on any pins or contacts... Looks like I need to chase wires...

 
So questions are, with access high pressure switch unplugged should the fans still run via signal from ecu?



Edited for clarity, damn phone auto fill.

[Steve Wood]

The moral to this story is to not buy things until you know what is causing the problem as it can get really expensive in a very short time.

A side note is that most of us discard the delay relay because it has a reputation for turning the fan on in the middle of the night after a bit and killing the battery.

Now, there is a section on fan operation under Troubleshootin g on my site, I think that is what you have mentioned, but, I would like to be sure.  It takes you thru finding out what is the problem.

The first thing to understand is how the fans work.  The low speed relay is triggered by the ecm which grounds the dark green wire and that grounding is controlled by the temperature that is programmed into the chip.  If you have an aftermarket chip, that temperature is usually around 160-170 degs.  The TT chips kick the low speed on around 167-168 degs.  The factory chip, on the other hand, does not turn the fan on until the temp is over 200 degs as I recall.

The high speed fan control has nothing to do with the ecm.  It is grounded by the AC pressure sensor or the coolant fan temperature sensor.  High speed should come on when you turn the AC on, or when the temp gets up to something like 228 degs.

You say you have dual fans.  I don't know how you have the wired to the factory wiring.  You should not have them wired so that they both try to turn on at the same time because the start load will fry a relay pretty quick in most cases.

I have one of my fans wired to low speed and the other to the high speed in order to divide the load.  I understand John Spina has a wiring harness that delays the the start of one fan against the other but I have not seen it and I am repeating what I think I was told.

[Scott87]

Thanks for the info I am going to keep at it.  I bought the dual fans when I purchased the new radiator..  It does have a caspers harness..

I am going to keep looking maybe a loose connection.

I have read the trouble shooting section I will read it a few more times before I continue...

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[Steve Wood]

With the key on, you should have power in the brown wire at each relay.

You should have power in the red wires all the time.

With the key on, if you ground the dark green wire, the fan should run.

If you ground the green/yellow wire, the fan should run when the key is on

[Scott87]

So in forward accessory position not on should have voltage in the brown wires.. 
I will have to double check,  Phil was notorious for satin black spray bombing..



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[Steve Wood]

turn the key until the check engine light is on...brown wires should then be powered

[Scott87]

Thank you Steve much appreciated.. 

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