how many amps is the FFR fan, and calling all EE's & wire spec gurus...

[NiceGuyEddie]

one of the summer mods on the list is flipping the fan and running the wires in a more hidden fashion. (i have a fan shroud now, but the wires still come out the top like above.)

i spent a long time doing this, and then i wondered if my wires are too thin of a gauge. the black and blue on the cut harness are the wires that came on the FFR fan. there are no markings on these wires, but they are copper in color and thicker than the wires i used to extend everything. (thicker wire and insulation.)

at work, we use the wire on the left for some pretty hefty HID lighting applications. our one and only EE left and nobody knows much about the specs of the wire. what i know is this:

the wire is silver in color.

marking on wire says: 105ºC E132813 AWG (0.823mm 2) (UL) MTW or AWM 1011/1015/1235/1235 600V or 1032 1000V MOISTURE RESISTANT VW-1 182067 CSA TEW



by this, are my extension wires beefy enough? that 1000V rating seems to say a lot... but Ohm's law was 24 years ago in Circuits 101 class...

[AUME2010]

Voltage doesn't really matter in this situation, that rating is the insulation's rated amount of voltage before it can arc through it. You are interested in the current draw limit before the wire gets too hot and either sets something on fire or acts as a fuse and burns in two. Below is a wire chart, the mm2 number is the cross sectional area of the wire, your wire is 18g so it will carry 16A in free air. (Second link for chassis wiring load limits which is in air. I'm lazy and not searching for a link with the full chart .) Shoot somewhere in between the limits and you will be pretty safe. A 1600cfm fan pulls around 15A maybe a bit more or less. So you are approaching or possibly exceeding the limit for that 18g wire. Go down to the parts house and pick up a roll of 12-14g wire to be safe. I always wire heavy, really want to avoid an electrical fire if a $5 roll of wire can prevent it.

American Wire Gauge (AWG) Cable Conductor Size Chart / Table

American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies

[rich grsc]

TOO small! Just judging by eye I would have said 16 ga, you need at least a 14 ga. Just take the connector with you and match the wire size not the insulation size, at the parts store.

[itsaw0rkinpr0gre$$]

How long is the run? What is the current draw of the Fan? 15A or is that what it's fused at?

this calculator should tell you what you need to know. Don't forget to estimate the total length of both power and ground cables when you enter into the calculator. http://www.gtsparkplugs.com/WireSizeCalc.html

[Big Blocker]

Eddie,

I wouldn't use anything less then 14ga for a fan, fused for as close as possible to the actual current draw. Example; 15-16 amp draw, fuse for 20 . . . wired thru a relay to take the load of the fan.

FWIW,
Your HID applications at work are probably designed to run on 277/480 and use less current at that higher voltage then if they were run at 240/120, hence the smaller wire.

Doc

[Bob Taylor]

Nice wire chart in the first post ! I'm no jeenyus but her is how I look at it . That is the perfect place for your relay. Use that little wire to actuate it , very low load 2-3 amps to turn it on and you can actuate the relay with power or ground. I agree on the heavy wire usage and would like to add wire long as well ,hope this helps Bob

[NiceGuyEddie]

hi bob: i've got a fan relay in there already, thanks.

i am still curious as to what gauge the green wire is. all that info and i can't see on the charts what gauge it is. i guess i'll have to take a micrometer to the wire?

as far as it looking too small, keep in mind the copper one is stripped and naturally fraying, i wound tight the stripped green wire in the photo. the diameters of the wires (when tight) are closer to each other than shown in the photo. (insulation on fan wires thicker too.)

i just checked and the wire on the main wire harness looks about the same diameter as the green wire.

i'm going to beef up the wire on the fan assembly anyway.

.

[scotworthy]

Got a wire stripper?

7" Wire Stripper with Cutter

Just put the bare wire in one of the holes. That should get you close to knowing the size.

[tirod]

There's some good reading here that makes a case: Motorsports ECU Wiring Harness Construction

While I don't suggest that paying more than a Mercedes is a goal in wiring, the Bonneville comments are cogent. I drive old cars, and wiring on old cars is a continual headache. Like the Bonneville racer, first years fine, later years a few repairs, after 15 years it would be cheaper to completely replace a factory harness than keep a mechanic on retainer fixing things. If someone's Honda is still good to go, fine, I suspect it was a Sun Belt car ( the link is a CA address.) I've not seen that kind of service in a Snow Belt car.

At the very least, shrink wrapping connections and using tinned multistrand conductors would be a huge step up. If we take the use of AN hose and fittings as a standard for a well built car, how much more should we use Milspec as a wiring standard? You can't drive on public roads without spark and turnsignals.

It's much easier to service a short length of hose clamped fuel line that track down why the car blows a fuse and kills the engine every time you honk the horn. Yeah, I drive old stuff, and it's been an education.

[AustinSnake]

Eddie,

.823mm**2 wire (marked on the insulation) is 18 gauge by definition.

This would be rated for < 14 amps at above 85C or so if memory serves, before bad things start to happen.

I would use 14 Ga.


Good luck!
Brian

[VdubJoe]

Also make sure any wire you buy has AWG on it as there is a lot being sold without and the sizing can be way off being undersize.

Joe

[CraigS]

If you have a West marine store available get your wire there as it's usually very good quality.

[Big Blocker]

Eddie,

Here is a simple guide for your automotive wire sizing concerns:

Typical Low Voltage Wire Sizes Guide

Air Conditioning- 10 GAUGE
Heater Switch- 10 GAUGE
Alternator- 8 GAUGE (this will depend on your choice of alternator)
Horn Button- 12 GAUGE
Ammeter- 10 GAUGE
Horn To Relay- 10 GAUGE
Cigarette Lighter- 14 GAUGE
Ignition Switch- 12 GAUGE
Clock- 18 GAUGE
Low-Amps Circuits- 18 GAUGE
Coil Wire- 16 GAUGE
Parking Lights- 16 GAUGE
Dome Lights- 16 GAUGE
Radio To Fuse Blocks- 14 GAUGE
Driving Lights- 14 GAUGE
Single Bulbs- 18 GAUGE
Gauges- 14 GAUGE
Starter To Relay- 16 GAUGE
Stoplights- 16 GAUGE
Tail Lights- 16 GAUGE
Headlight Circuit- 14 GAUGE
Turn Signals- 16 GAUGE
Headlight Switch To Fuse Block- 12 GAUGE
CD To Fuse Block- 14 GAUGE
Heater Leads- 16 GAUGE
Windshield Wiper & Washer- 14 GAUGE

For safety and best results; When circuit is longer than 10 feet, always use the next larger gauge size, which is the next lower even number.

These are guidelines only, every circuit is unique and should be evaluated before deciding on the wire size to use.


Doc

[NiceGuyEddie]

thank you gentlemen....

as Edd from Wheeler Dealers would say, "I put right the fan wires and tidied up the engine bay a wee."

english translation: the wires are now completely hidden.

when i tested the fan, it didn't seem to blow as hard as it used to, or even make as much noise, but the engine has not been started for a long time. i thought it was a low battery. the car started up with no problems, and i let it run for 10 minutes.

even after that, the fan didn't seem to blow as hard and make as much noise as it used to. i hope i'm just not remembering properly. i'm going to have to visit a local and check out their fan.


.

[rateike]

Since you have some extra wire and it is currently wired and you are questioning the speed of the fan. You could run a second wire in parallel and see if the fan speed increased a lot. That will tell you if it is wire size limited. Then re-wire it with the correct wire gauge.

You could also measure voltage drop with the current set up and after you add the parallel wire. Then repeat it with the re-wired set up using the correct wire gauge.

Lee

[NiceGuyEddie]

believe it or not, the extension wires are now 12 gauge. i could not find 14 gauge. i will definitely do the voltage drop thing.

strangely, the headlights did not work, even after starting the car. but after a short while they worked. the headlight switch (pull) may have had some tarnishing on it. the lights worked after i went in-out on the puller knob.

i really scared myself for a while.

.