If you have DDDL You could very easily install a manual fan switch that looks factory and would be in the same spot where all your other switches are and you won’t have to worry about getting a cel or faults for tapping into the fan sol wiring physically
This way will work but when you manually give the ground to the fan solenoid check engine will come on. If you add a diode on the ground side, check engine light will not come on.
Wc would this fan switch work for western star with dd15. I had someone installed a switch but I get the check light every time is on . I think they just bridge the cables. One connection goes to selanoid and other to battery for power. Every time the check light comes on I have to stop and turn the whole system off for the light to go out. Please let me know how to correct it or can I do an air toggle switch directly onto the selanoid air line.
Sounds like it was wired wrong. To break a circuit, break the ground and run that to the toggle switch, if you break the positive you will get a check engine light. The solenoid only has 2 wires, positive and ground. Sounds like you need a new mechanic.
Ok thx. One more question. After I wire it the way you show will it do any cycle automatically if I don’t turn the switch on or I will have to do it manually for now on.
@@VictorGomez-ur3zk so the toggle switch has 2 positions, one will complete the circuit as if the switch was not there and the fan will work as if no switch was installed. So fan will come on automatically when the ECU tells it to. The other position of the toggle switch will break the circuit and when that happens the fan will come on, the reason is if the fan solenoid goes bad the fan will stay on as a fail safe. Easy fix for you, just reconnect the power wire, and cut the ground wire and splice your toggle switch in. If you change the length of any wire that has power, the ECU will throw a check engine light. You will still get a check engine light doing it my way also if your are parked or even going slow in traffic. But never going down the road at speed, not sure why that happens to be honest. But it does not derate and will clear itself out in 20 or 30 minutes on its own. This switch is really just to control the coolant temp going up long grades, as not to heat cycle the engine. I believe going up mountains at a constant 200 degrees is way easier on the engine than letting it bounce between 200 and 225 over and over and over. If you are having overheating issues this will not fix your issue.
Just know if the fan is turned on while parked the check engine light may come on. It will clear itself as soon as you turn it off. Does not happen driving.
@@tabcaan22 from Freightliner, find diagnostic link on google and you will be able to purchase it. You have to show you own the truck or a shop to be approved.
The manual fan is completely unnecessary and will cost you more money in terms of fuel. Also, to my knowledge, the fan on modern trucks is probably always running, although at a low speed. When the fan runs at high speed, you lose engine pulling power. If you pay close attention to your RPMs while on a long steep upgrade, you will notice that immediately after the engine fan begins to run at high speed, your RPMs will drop fast. So, if you have your fan running at high speed the whole time while driving, you’re literally reducing the pulling power of your engine. I’d say, let the fan run at high speed only when it needs to. That being said, there is a time when damage can happen to coolant seals and hoses if you allows the coolant temperature to rise to the “red area” on your coolant temperature gauge. For example, you drove up a steep upgrade for 15 minutes and stopped at the top of the mountain for a break. At this point, it is important not to turn off the engine. If you turn it off, the coolant temperature will be in the “red area” next time you turn on your engine. To prevent this, you gotta let your engine idle for 5-15 minutes depending on how steep the upgrade was.
I disagree, every truck used to have one as we know heat cycling the engine back and forth between 205 and 220 is not great for the head or the engine going up a long hard grade. The reason they are not on trucks now as steering wheel holders will leave them on and you are correct, it will cost you a 1/2 mile to the gallon. Pittsburgh Power says it takes 50hp to run the fan. I’ll give up some pulling power to keep the engine around a constant 195 up a hard pull. Plus I have a Pittsburgh Power Tune set at around 600hp, so not a issue for me. Also fans are controlled by a solenoid that either supplies air to let the fan freewheel, or cuts off air to engage, there is a clutch to let it engage slowly, or you would rip the belts off.
@@wesley_scott I’ve heard about damage to the engine, but my truck has 935k miles in it and still running hard. I got the truck at 355k. No engine rebuild yet or major repair done to it that I can attribute to the coolant temperature occasionally fluctuating between 205-220 and the engine fan not running at high speed. I’m also not sure I’ve ever heard anyone claim that they needed a rebuild or particular repair because of their coolant temperature. My guess is that engineers made modifications to the engine so they could safely put the engine fan on automatic without damaging the engine. Also, on the DD15, the “red area” sits at about 241 F, and the fan runs at high speed right before hitting 225.
@@thereviewer4173 it’s just a video of how to install, not to debate personal antidotal experiences of if a fan switch is needed or not. You can order a brand new truck with the fan switch installed when built and have a little extra control over coolant temp or let the ecu do it, both ways are fine, it’s a owner’s decision.
@@wesley_scott I’m just sharing my experience, and I don’t mind being wrong if they can prove it. Some people don’t like to be questioned, and that’s okay.
Just know if the fan is turned on while parked the check engine light may come on. It will clear itself as soon as you turn it off. Does not happen driving.
