Actually, I don't need help with the FAN. However, it runs off a push-pull switch in the dash and I'm trying to install an LED indicator light to let me know when the fan is switch on. Problem: I cannot get the LED to come on when the fan is on. As best I can tell, here is how the fan is wired up... [FONT="]There is a hot wire running from the battery (+) to the alternator (white insulated wire)[/FONT] [FONT="]There are two wires coming out of the electric fan - [/FONT][FONT="]both read hot w/ a test probe[/FONT] [FONT="]Fan wire A (black) goes to the hot terminal on the back of the alternator [/FONT] [FONT="]Fan wire B (blue) wire appears to run to terminal A of the pull switch (not 100% sure) [/FONT] [FONT="]The wire from terminal B of the pull-switch runs through a small relay (???) and then I don’t know where (perhaps to ground?) [/FONT] Results with test probe hooked to (-) battery terminal... With the pull-switch OFF (i.e. pushed in) fan wires A and B both read hot With the pull-switch OFF (i.e. pushed in) terminal A of the pull-switch reads hot and terminal B reads cold With the pull-switch ON (i.e. pulled out), neither terminal of the pull-switch switch reads hot, but the fan is running (huh?) At first, I tried running the LED power from terminal B of the pull-switch, and the other LED wire straight to ground. That didn't work. So I switched it to terminal A - which is hot with the fan off - and the LED still didn't work so I thought maybe the LED is bad. Just for kicks I turned on the fan and the LED still did not light up so I was sure I had a bad LED. But when I switched the fan off the LED lit up brightly then slowly faded out. Now I am completely corn-fused !!! I've been looking at fan wiring diagrams online today and nothing looks like the wiring I have. I also wrote the previous owner for info, but no replies yet. Given the current wiring of the fan, can anyone suggest how/where to hook in the LED so it will illuminate when I turn on the fan ???
Hook one side of the led to a known hot wire, then the other side to "B" on the switch. If the switch is controlling the ground side of the fan, it will light up then. I had my electric fan wired that way, switching the ground side in case the switch shorted out all that would happen is the fan would come on.
2 ways I think,,, lighted switch and no light,,, led has to be hooked up +=+ and -=- ,,, hot wire to positive side of led and negative wire of led to terminal A of switch. The "small relay" is throwing me, may be a diode, not sure why or what it is. When you turn switch on, that connects Switch terminal A to terminal B which is your ground, Grounds are hot or showing voltage when open or wire is not grounded if you know what I mean. Possible that led will feed fan, I dont think so, I would try and let us know how it works.
Manually switched electric fans scare me. Manual control has its advantages, but if you ever forget to turn it on, or (more likely) someone else forgets or doesn't know about it... Disaster. "But nobody drives my car but me" you might say - me too, but I can easily envision a number of emergency scenarios in which somebody else might have to take the wheel, and a breakdown is the last thing I want while I'm unconscious being rushed to the hospital for instance. I know that sounds crazy and paranoid, and tons of people run manually-switched electric fans with no issue, but the rare situation in which it might cause trouble is likely to be the one time when you can't afford any.
I agree . I don't see the need for manual switch on elec fan when there are so many simple thermostatic switches available. If manual were the way to go, I invision they wud be put on cars from the factory. I can see a manual bypass in case the thermo switch fails - but I wud think that wud be a rare occassion. I just installed elec fan setup and never once considered a manual switch. I'll take my chances w/ the thermo switch. JMO
Agree totally about using a thermo switch w/ override kill switch. Previous owner wired up the fan w/ manual switch and I just wanted to put in an LED indicator. Ended up running one lead from the LED to a hot source and the other to terminal A of the fan switch (don't really know why this works but it does. Starting to get the feeling a good project for next winter will be cleaning up all this add-on wiring and replacing the original fuse panel with a small blade fuse unit...
the light only tells you that there is power going to the fan. the temp. guage will tell you if the fan is working...
Terminal A is switched ground, B is always ground on your switch. Negatives until grounded will show voltage.
