Frequently Asked Questions:
How often do I need to replace my relays?
For the daily driver grocery getter with rear air we recommend replacing your relays annually. Vehicles with rear air and extended cabs will be different than a regular cab truck or weekend driven vehicles for obvious reasons.
What is PCM Controlled?
It simply means they are controlled entirely by the computer on the vehicle. No temp probes or switch for you to manually operate or have to pay attention to. The vehicle is "tuned" through the PCM using editing software such as EFI Live to re flash the operating system parameters.
What dose "tuned" mean and where do I get it?
It means having the parameters of the PCM changed or adjusted for modified and adjusted for performance, economy or when aftermarket parts have been installed to gain the absolute most out of your investment. For more tuning info and where to get it done, click HERE.
What is OEM operations?
This means the fans operate just as they would like the late model trucks currently sold do. 2 fans High, 2 fans Low and one fan high. This is the same operations that GM has used on the Corvette and Camaro for years. With the demand for higher MPG and better emissions this helps to achieve that.
Do PCM controlled fans operate continuously?
No, they are only triggered if coolant temp value setting are met and seen by the PCM. In fact in the cold winter months the fans may never even turn on unless you use your defrost. This is all depending on outside ambient temperature.
How much horsepower is gained?
None, you are simply freeing up what is already there being bled from the Engine Driven Fan that is robbing Rear Wheels of HorsePower.
What makes electric fans so efficient?
The ability of being shut down when demand of set temp values are not met. They simply are only ran when engine coolant reaches activation temps. They typically shut down when the vehicle reaches 40-45 mph and or freeway operation. They are just not being used continuous like the Engine Driven Fan is shutting down when not needed adding to the efficiency of operations.
Do I need an alternator overdrive pulley?
Thats something that varies from application to application and can only be answered by you. Generally all 105 amp alternators do need one. The 145 amp alternators are usually ok, unless total amp draw from your accessories exceed the peak alternator amp/voltage output at any given RPM. It just depend on how many accessories you are running. Compressors, lights, winch, fans, stereo ect. ect.
How many amps do the efans pull?
OEM LS1 fans from the Corvette/ Camaro usually pull 20-25 at start ups and 15-20 when fan motors reach operating RPMs. The 05+OEM Tahoe/Silverado fans pulls abit more, usually 25-30 at start up and 18-25 during operation. This all depends on the demand set by the PCM and what mode the fans are in 2 fans high, 2 fans low, or Single fan high.
Will the alternator overdrive pulley prematurely wear out my alternator?
No, it's just 52 mm O.D. and just 5 millimeters smaller than the 57 mm O.D. of the stock pulley. We are just increasing available amps at idle, by advancing rotor RPM by a bit.
Can I install an manual override switch?
Yes if you would like.
Do the relays terminals need periodically cleaning?
No, we use die electric grease during assembly and should last the life of the relay.
I Recently replaced my relays and the fans dont work, whats wrong?
One of the relay terminals have most likely been pushed out the backside while re inserting the relays. Peel the loom at the terminals back and check them out. If so, reset the spade lock(being careful not to break it) and reinsert into the terminal block.
Can I extend my power and ground wires?
Yes you can, but be careful. Not using the right butt connector, improper soldering or not using shrink wrap will void your warranty.
I bought a used harness and it's not for my application, can you send me a wiring diagram?
No, sorry we are under confidentiality contract agreement at LS1Fans.
Will my harness work if Im upgrading from LS1 to 05 fans with the 34" radiator?
Thats kind of a trick question. Yes, but you'll have to change fan motor plugs on the harness and only if its in the same vehicle. If they are going in to a completely different vehicle with different operating systems then you will need the harness to work with that system. See our applications page for applications here.