How to make my 2nd cooling fan kick on with a switch
06-30-2013, 06:57 PM
#1
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How to make my 2nd cooling fan kick on with a switch I have an LS2/4L60e in my 70 El Camino. Motor & trans from an '06 GTO.
Speartec reworked harness. Car doesn't over heat, and the 2nd cooling fan never turns on. Is there an easy way to make that fan run using a toggle switch, that won't interfere with it's normal operating mode? Thanks for any ideas.
Blanchard
Speartec reworked harness. Car doesn't over heat, and the 2nd cooling fan never turns on. Is there an easy way to make that fan run using a toggle switch, that won't interfere with it's normal operating mode? Thanks for any ideas.
Blanchard
06-30-2013, 11:52 PM
#3
Yea the easiest way I think is to just buy a thermal switch from summit or JEGS and thread it into unused spot in the driver side cylinder head and the switch has two spade terminals...for example my switch triggers fan on at 175 and off at 195...you run an ignition hot wire to one of the spades, then run a wire from other spade to trigger side of relay, then a battery hot wire to other side of relay...all of this is assuming you don't want redneck rigged toggle switch, but to each his own good luck bro
07-01-2013, 08:21 AM
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If the GTO setup is like an fbody setup, then the OEM fans on "low" run in series, and on "high" they run in parallel. This setup has three relays.
Does the Speartech harness have one or two or three relays for the fans?
If it has one fan relay, then you need to run the fans in either series or parallel off the one relay. Or add a second relay for the second fan.
If it has two relays, and each relay is wired to one of the fan motors, then you are never getting the engine hot enough to trip the high signal output from the ECM to the relay. You could jumper the control sides of the two relays so both relays fire on the low speed PCM signal.
If it has three relays to make the change between the series and parallel fan control circuits for low and high settings, then I guess it is wired wrong, given that the OEM setup never has a single fan run. On low both fans run a a lower speed due to each getting half the voltage drop.
All the above assumes the fans are wired correctly to begin with.
To make it run on a toggle switch, you need to wire a toggle switch to supply 12V to the control side of the fan relay which does not run, assuming this relay is present to begin with.
Does the Speartech harness have one or two or three relays for the fans?
If it has one fan relay, then you need to run the fans in either series or parallel off the one relay. Or add a second relay for the second fan.
If it has two relays, and each relay is wired to one of the fan motors, then you are never getting the engine hot enough to trip the high signal output from the ECM to the relay. You could jumper the control sides of the two relays so both relays fire on the low speed PCM signal.
If it has three relays to make the change between the series and parallel fan control circuits for low and high settings, then I guess it is wired wrong, given that the OEM setup never has a single fan run. On low both fans run a a lower speed due to each getting half the voltage drop.
All the above assumes the fans are wired correctly to begin with.
To make it run on a toggle switch, you need to wire a toggle switch to supply 12V to the control side of the fan relay which does not run, assuming this relay is present to begin with.
