Topic: toggle switch cooling fan
in Forum: C4 General Discussion
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Reading these numbers right from FSM. these are for the HIGH SIDE of system page 8a-31.I know these numbers are high for R 12 or 134a which I now are using. I"ll probably change thermostat to 180 deg. and change coolant sensor switch to 200 -205 deg range.Thanks for your input. No aux fan.
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Hi,
you can fairly easily connect a manual switch to jumper the coolant temp sensor which will operate if the coolant temp reaches 240F. This is positioned at the left side of the engine and operates by connecting the lead to earth, energizing the fan relay. Thus, you need to wire your manual override so that you can provide earth when desired.
I ve routed the wire to pass through the driver's side door seal to underneath the dashboard. earth connection was made using a redundant bracket next to the brake pedal mounting. didn t manage to get anything through the front bulkhead, which would have been first choice.
this installation works well and provides peace of mind, as the standard switching temperatures (240 on, 230 off) are very stressful for the engine esp the head gaskets.
bye
Wolfram
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Mission Viejo, CA - USA
Joined: 3/18/2015
Posts: 74
Vette(s): Yellow '84 Coupe
wolfuser said:I've routed the wire to pass through the driver's side door seal to underneath the dashboard. earth connection was made using a redundant bracket next to the brake pedal mounting. I didn't manage to get anything through the front bulkhead, which would have been first choice.
Wolfram
Wolfram, your '87 is different than eugrides '89. His radiator fan is controlled by the ECM, so he's trying to be creative to bypass the ECM, rather than finding a way to re-program his ECM to lower the fan turn-on temp.
I believe your '87 wiring is like my '84. My radiator fan is also controlled by a coolant temperature switch (CTS), like your '87. I'm sure the wire thru your door gasket works, but it's a bit awkward. If I'm right about your wiring being like my '84, there is already a wire under your dashboard where you can connect your manual switch. It's a jumper between the top and bottom connectors to the left of your steering column. In my '84, it's a grn/wht wire between C110-2F and C115-7E.
Green/White wire pic
Have you considered replacing your CTS with a lower temp. switch? The ACDelco D1855B works well for me.
(large image modified to link-aapple)
|UPDATED|5/10/2018 7:04:05 PM (AZT)|/UPDATED|
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Perkinston, MS - USA
Joined: 3/8/2018
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Vette(s): 1993 40th Anniversary Coupe
Hello to All.........
What is the CTS and where do I find it?
gary
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Mission Viejo, CA - USA
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Vette(s): Yellow '84 Coupe
garyjackso said:
Hello to All.........
What is the CTS and where do I find it?
gary
Gary, I explained what the CTS is in my post, but since you have a '93, you don't have a CTS (Coolant Temp Switch). Your radiator fan is controlled by your ECM (Electronic Control Module), or whatever it's called in your '93. This question is about the early C4 system.
|UPDATED|5/11/2018 12:07:42 PM (AZT)|/UPDATED|
After further investigating I found I do have an aux fan and a sensor between #1 and 3 cyl. I really just want to put a manual switch on my main fan as the aux fan is missing some screws.My Main fan relay is on left side of fan shroud. I am going to run a toggle switch to ground on ground wire on relay and still keep wire going to computer so I can start fan sooner if I want . Any problem with that
Mid America sells the switch you need and posts the instructions for all years on their website. The price is reasonable and if you follow their directions you can't go wrong.
Rarely indicted, never convicted
in Forum: C4 General Discussion
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