About a month or so ago I installed a Taurus fan into my 83 Tbird. It's a well documented modification and supposed to gain me some more power and fuel economy by reducing engine drag. But I feel like it's doing the opposite. Every time the fan comes on my idle drops 100 rpm. I've tried to rewire it by separating the fan and ignition as much as possible but to no effect. I do know I need to use a thicker gauge power wire to the fan because relay plugs and wire loom around that wire keep melting (damm cheap fan controller). But that shouldn't affect my ignition should it? And just so you know I'm not using the stock alternator, it's a 3G, so there shouldn't be amperage problems.
Year you will lose engine drake from the fan. But it uses a lot of power to turn it and loads down your alternator that’s why your engine drops in RPM. Sort of like when you turn on car A/C it puts a load on the motor.
Man I didn't even think about the magnetic drag caused by the alternator. Now it makes sense.
Best bet would to do a 130amp alternator upgrade. The Stock 83 unit is only like 61amps if you have A/c. I belive the only difference in the factory Turbo coupe is the T/C has the 2 groove pully. So check to see if 93-95 stang unit is the same basic shape and then search for the wireing very very simple. You will need a tap to thread the hole in the new one or use a nut/bolt with lock washer. Then you can even get ride of that external regulator to help clean up the looks of you ride a little. Very simple if you do this post on here if you need help. Very Very simple even the wiring. Did this swap on my 84 turbo coupe and now no more headlight dim with everything on at idle. When your fan turns on the lights will dim for a split second. Much more efficient unit that way is should have less drag on the motor also.
What amperage 3G do you have?
I took it from a 95 Taurus 3.8. When I brought it in to be tested at Partsource I had them look up the replacement part and it was 130 Amp.
Well, I'm betting you're just going to have to deal with the slight rpm drop. Alot of the older factory cooling fans have a pretty high amp draw.
I have a 130A 3G on my 83 and a set dual aftermarket fans. I really don't even notice them coming on.
Maybe you fan controller setup is junk. I've also got dual after market fans by hayden. I also have there adjustable fan controller. I don't seem to notice the fans kicking on unless everything it quiet and I here them.
I would lean towards a bum fan controller/poor wiring connections...when you did the 3G swap...did you buy the proper gauge power cable from the alt to the solenoid(like the one from PA performance). I remember when I did my 3G swap I didn't upgrade it and ended up not seeing any benefits and was starting to melt the wiring at the alt...after I got that, everything was good. Double check your wiring...even tauruses dont lose rpm like that when their fans come on...lol.
This thing rooks, I'm on my second summer with it and it works great. We're in a heat wave right now in Philly with high 95+'s temps and huminity that makes you want to cry and I'm chilling in traffic with the a/c on :) with no problem.
http://www.dccontrol.com/
I bought the fk-35
Could be the battery. I has having the same problem with my 87 TC w/ stock fans. They are both wired through a switch and my idle would drop about 100 rpms when I cut them on. This never happened in my 88 TC. The engine would idle rough and it just sounded completely different. I tested the alternator volts and they were around 14.XX volts. Later on, I swapped out a battery due to starting issues and vola... no idle drop. Even with the headlights on. Also clean your connections too.
Go with aftermarket fans, they don't cost much - 50 bucks for the one I have. I don't notice at all when it kicks on. It might draw 20 amps at most. My stereo causes more drag on the system :D
Lol. Didn't even notice this thread had resurfaced. I connected the alternator to the solenoid with a 4 gauge bat cable so there shouldn't be any issues. My battery is a Motomaster Eliminator, not exactly a racing battery but pretty heavy duty still with 850 CCA. I am in the middle of replacing the fans power wire to the relay because the wire that came with the controller just can't cut it (the connector on the relay was melting a little more each day). Need to buy some more heat shrinking connectors to finnish, maybe things will change for the better with a 10 gauge wire powering the fan.
Mine JUST shipped after waiting for a month. What are people recommending for wire gauge? Using a Mark VIII fan, I'm thinking 8 gauge to give it some spare capacity.
sum_weirdo, what is the voltage at the alternator, battery, and fan?
If you're still having problems...these measurements could shed some light on the situation.
Seek, I'd just use the 10-gauge wire that comes with the FK-35. It has worked just fine for me.
One big advantage of the DC Controller is it only draws enough current to cool the engine. I measured voltage input to my MN12 fan from my FK-35 while driving around last summer and the highest I ever got was ~8V (~15A). At a stop...it wouldn't go over 6V. This makes life much easier on your alternator.
Yeah mine took about 3 weeks :( , I cut the mark8 harness and used that I was lucky enough to find the car+fan in a upull it lot..