I'm getting back to addressing my Taurus Efan issues. I previously created a thread but it go so off topic and about general charging systems that the title was barely true.

I have the fan wired up using this diagram. I do not have the idle up wired in yet.


I'm using 10ga wiring all around with a 40a resetting circuit breaker and I'm only using low speed in winter time. I have a modded 130amp S5 alternator and a new yellow top Optima. I have to ground the fan to the battery because it throws the resetting breaker if it's grounded to the chassis. The fan will run for some time before the circuit breaker goes.

I had the engine idling and put a DC amp clamp on the fan power wire and here is what it told me:
Start up: 71 amp pull
Constant: 24.4 amp pull
if I increase rpms to 2-3k amperage on the fan increases to 31.3 amps and you can hear it speed up with the rpm of the engine. Related issue, the lights grow brighter with rpms also.

Those numbers seem high for the fan on low speed.

About the lights brightening and fan speeding up with the RPMs. I don't think it's voltage regulator because the modded alternator is newly modded. I'd like to think that means it's in good working order. I've been told my grounds have too much resistance in them. I'm going to retest them and go from there with the grounds. I'll see if cleaning up or replacing the grounds doesn't fix that issue.

 

Your start up (and even the constant) draw seem very high to me.
I've run the Taurus and even the larger Lincoln fan on a 30a fuse for years now without a problem.

Is your fan new or used?
You can buy replacement fan motors pretty cheap, yours may be on its way out.

 

It's a used junkyard find. I was going to replace the fan today, but figured I'd create a thread before I threw money at a problem. I was just starting to read up on testing DC motors. That being said, before I head to the junkyard I'll check prices on replacement motors.

 

Rock Auto shows them for between $50 and $150...not sure why the great span in price.

You have a troubling problem.
The high current draw would indicate a bad fan motor but the fact that the lights and fan speed vary with RPM would point to the alternator.
Does the light output track rpms with the fan disconnected?

 

+1 for Clokkar's assessment. Your current draw is too high. Low speed on a Taurus Fan is ~20 amps, High is ~30 amps. If you're using anything less than a FD Alternator, I would suspect that you could see the voltage drop when the fan comes on. That is, if the car didn't stall first But in all seriousness, check your actual voltage as I would suspect your 130A S5 Alternator is not as advertised.

Another thing I want to point out is that a circuit breaker is a thermal protection device. When I put an inexpensive 150A breaker on my alternator cable (130A Taurus Alt), it would trip after the engine was running for maybe 10 minutes at most. When a breaker heats up, its ampacity drops. I suspect your breaker is heat soaking the same as mine did. Even with a heat shield, it just couldn't take the heat of a 20B-REW because it kept heat soaking. As Clokkar suggested, use a fuse here. My Taurus Fan has a 50A Maxi fuse that feeds both Low and High Speeds through two relays with individual triggers.

Also, I don't mean to nitpick, but why are you STILL having the relay on the Ground side of the circuit? This is not good wiring practice as grounds need to be as short and simple as possible to ensure good performance. Run an 8awg wire from the fan's connector straight to the chassis. Ground it per Aaron Cakes Grounds Article and it will eliminate it as a possible point of difficulty, making any an all potential troubleshooting on the positive side of the circuit only.

Battery---fuse---relay---fan positive

Relay wiring:
30: Battery
87: Fan Output if using a S5/Normal style thermoswitch (on @207)
87A: Fan Output if using a S4/Backwards style thermoswitch (OFF @207)
85: Ignition-Switched 12v
86: To Thermoswitch, Manual Override Switch & Idle-up pin (Optional, pin 1O on S5 ECU), wire all 3 in parallel

When the thermoswitch supplies its ground to the relay, it also supplies a ground to Pin 1O on the ECU. Idle-Up is triggered to bump up the alternator's output and the fan turns on. Same thing happens with your manual override switch.

 

I always like to buy new things, especially things like fans

I bought a "new" taurus fan from rock or someone, I forget it was a few years ago.
The motor was TINY. I ended up returning it and bought a fan from that guy on ebay who says he has the cleanest junkyard fans ( there are no u-picks around here ) and its been running great.

If you do decide to buy a "new" fan, dont go for those $50 ones I can guarantee you it will be junk.

 

I'll check tomorrow with the fan disconnected.

I had the previous modded alternator tested at two different shops for output. I first had it tested for voltage and it showed it was charging correctly. Later that week I decided I wanted to know amp output and took it to a different shop. It was putting out 128 amps. I have not had this one tested, but it's from the same shop.

I went with the resetting breaker because the fan was eating fuses. When my rebuild was still in my 89 vert I had the fan first on an inline fuse holder. Then moved it to an open space on the engine fuse holder using FMX fuses. Those were melting also. With the breaker grounded to the chassis it trips, but as long as it's on the battery it does not. Really the breaker was a temporary fix till I figured out the fan issue. Since the engine has been swapped to the 90 vert I've put less than 800 miles or so on it since last summer.

I do remember getting advice about changing how the fan was wired and have intended to do that. BUT between work and class I only work on the car maybe once every 2-3 weekends. Sometimes I don't even get to play with my car that often. With the upcoming change with the fan I'll be rewiring it also...and thank you for walking me through the relay pins.

I was going to get a Taurus fan from a pull-it-for-you yard today. I called and figured me asking how much the fan was ($40) meant they also checked if they had any in stock...boy was that a mistake on my part. Drove out there to find they didn't have any.

I've seen on ebay and web shops that I can get motors for anywhere from $70-100. What I haven't seen yet is a motor with the same wiring harness as I have. Mine has harness in a triangular configuration, like so:


So far all I've seen are the flat, inline pins. Not that big of a deal if I had to switch but would prefer to not have to.

 

Why concentrate so much on the plug?
I have the flat plug https://www.rx7club.com/2nd-generati...n-plug-851697/

 

Thanks for the link. I'd like to keep the same plug simply because it saves me time in driving to the junkyard and pulling one. Oh yeah and researching the pin out on the harness.

Keeping the same plug certainly isn't a deal breaker, but it'd be nice.

 

With the fan unplugged I still get lights brightening with RPMS. The heater blower also changes with RPMs.

 

That ain't right.

When you had the alternator tested, did they mention the rpm?

 

No, no mention of RPMs. With it being a modded alternator it won't hit 14v unless RPMs are at/above 1000. On the OEM voltmeter I can watch the voltage jump from under 14v to 14v as soon as RPMs hit 1000. I wonder if that's not simply a product of having a modded alternator, seems logical anyway.

I believe I have an OEM S5 alternator lying around in storage. I could always pop it on and do a comparison. Fan unplugged, OEM alternator on and see if I have the same behavior.

 

This is a known issue with Rewinds! They do not put out full voltage at idle. Check a rewinder web site. They will warn you that the idle will have to be stepped up or the pulley ration modified.

And by the way, P=EI So if your fan pulls P watts and the voltage E is low, guess what HAS to go up?

So there you go.

Jack

 

Looks like this one is veering into charging system issues too.

 

After my last post I figured you'd show up with such language. As I was writing it I was thinking of the advice you had given about modded alternators in the past. Seems logical.

I didn't pay anything but shipping one way for the the new modded alt. I have a Taurus alt waiting if needed. If I can get the efan working correctly I'm ok with brightening lights and fans bumping up a little....so long as there aren't other implications beyond holding RPMs higher for full charging.

Sidenote: As a general precaution I'll flip my fan on when coming up to traffic lights to pull temps down so the fan isn't running as much while sitting at lights.

That being said, I'll proceed with making a bracket for the Taurus alt. If I can get it to fit behind my strutbar I'll use it.

 

Manual control of the efan is unnecessary and inefficient.
Get yourself a decent thermoswitch and let it do its thing.

 

I have not been able to source an efan. Went to the ONLY yard in my town that is open on the weekend and came away empty.

I am going to rewire it per Akagis advice. Does this look accurate?

 

Yes, that is correct for a single speed fan. With either trigger, Thermoswitch or Manual Override Switch, are activated, they supply a ground to both the Relay AND ECU's Idle-up pin. Fan turns on, BAC Valve opens, idle is bumped up to 850rpm.

 

Some success. Fan is rewired with 8ga ground on low and running only low and hasn't thrown the resetting circuit breaker. I let the engine idle with the manual switch turned on (fan blowing on low) and it never threw the circuit breaker.

Took it for a short drive tonight to class but the drive wasn't long enough for the thermoswitch to switch the fan on. On the drive home I drove some with manual switch on just to put a draw on the system. Nothing to really speak of other than I came out from class for the drive home and my Prosport water temp gauge was zeroing out on 220 (temps never got higher than 180ish while driving) when I started up the engine. Engine had sat for over 4 hours and that reading was far from accurate. It's done this before and the reading slowly lowers till it meets with what I assume are the correct readings. In the past when it has done this after I thought the actual temp and gauge had met and become accurate I put a temp gun on my water pump housing and it read about the same as the temp gauge. Tomorrow after work I'll look at the ground on the temp sensor.

Also after work tomorrow I'll get engine temps up to thermoswitch activating the fan and see how the fan and charging system behave.

 

I worked on this some more tonight.

Background is that low speed works just fine. Though I've started to notice that as outside temps are rising I'm testing the waters with it. Last couple of days temps have been in low to high 80s. When water temps reach 180 or so I manually turn on the fan. The fan will run till I reach my destination without the temps rising or falling....it just runs and runs.

That makes me nervous with heat of summer coming, so I ordered an inline maxi fuse holder. I removed the resetting breaker from the equation. What had previously been happening with the resetting breaker with fan on high is that the fan was kicking off after it had been running for varying amounts of time.

I just put the maxi fuse holder on with a 60amp fuse in it. I test it once with the manual switch. I idle the engine so the battery doesn't drain down and let the fan run for like 5 minutes. No problems.

I check amp draw on the fan high speed. LRA was low 60s, FLA was 33

I let the engine idle and water temps rise and the thermoswitch switches on the fan. It runs for a minute or two and shuts off before temps start dropping. I think I've burned up the fuse, BUT.... it is fine.

And that was my stopping point....I assumed with the resetting breaker the high fan was overloading it and that's why it was turning off. Now I'm wondering if that resetting breaker operated fine, cause clearly something other than the fuse or breaker is causing the fan to cut off.

Advice would be awesome

One thing to note: I ran 8ga wire from battery to relay pin 30 with inline fuse between battery and relay. I also ran 8ga wire from 87 to the fan. I could not find anyone in town that had 8 ga terminals or crimp butts so I had to trim off the wire on some of those 10-12ga terminals and butts.

 

Thermoswitch maybe?

 

Explain please? I use the same thermoswitch for high as low. I don't have two thermoswitches. If I want high rather than low speed I simply switch the wire connecting to the relay.

 

Actually, I've had good results by cutting off the yellow vinyl insulation on the 10/12awg terminals and 'overstuffing' them. A dremel with a diamond cutoff wheel works well to remove the insulation, while a pair of needle-nose pliers does well with opening up the crimp barrel slightly larger to fit the 8awg cable. Be sure to crimp it solidly with a non-insulated terminal crimper (the kind with a tooth to form a V-shaped crimp) and insulate it with heat shrink tube. Just for extra support, I give it two layers of heat shrink to act as a strain relief.

Also, Lowes and Menards both carry ring terminals suitable for 4awg and 8awg

You have me intrigued where you found an inline Maxi fuse holder. Care to reveal the source? The only ones I currently know of are Volkswagen parts. My fan runs through a 60A fuse in a clip-on VW holder with 8awg cables and never misses a beat. A 60A fuse is overkill and should never blow unless something is WAY wrong such as the fan motor being shot or the blades being stalled. Taurus fans draw about 30A on high, 20A on low, according to several sources.

To the best of my knowledge, circuit breakers have a temperature de-rating curve. The hotter the location, the easier it is for one to trip prematurely. I encountered this on my car when I had the 130A Taurus Alt running through a 150A breaker. After a few minutes of cruising, it kept tripping due to heat soak untill it cooled down.

Here is a chart to illustrate it. It's written for NEC building codes, but the same logic applies.: Industrial Control - High Density Supplementary Protectors (Miniature Circuit Breakers)

At 200 degrees Fahrenheit, my 150A breaker's actual rating was 93.75 amps. I don't know how hot it gets under the hood, but such a heavy penalty requires attention and reworking for adequate protection. Even with a heat shield, it still tripped.

A similar scenario exists with the FD. One person reported underhood temps in the same location (driver's strut tower) being 190 degrees. For our purposes, I'd say it's close enough.

 

We can debate the use of "simply" in the above context later, for now we'll talk thermoswitches.

Your switch has an "active" range...say it triggers ON at 195° and OFF at 185° (this is the spec on my low speed thermoswitch).
If you switch activates the fan at the expected temp but then shuts it down immediately, the switch could be faulty. It's easy to test with a pan of water on a stove, a thermometer and an ohmmeter, you might test it and see.

 

I ordered the maxi fuse holder online. Price shipped was under $9 shipped.
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I've been in a few electrical classes and they talk about amperage ratings related to temperature of the environment they are used in. You definitely need to account for temperature.

That being said, I have my relay and maxi fuse holder behind the bumper with the other OEM relays.

I've got a DC amp clamp for the meter. My readings were right where I expected from reading other people's posts about Taurus fans. low 60s on start up (LRA) and low 30s running (FLA).

Any ideas why my fan would cut out without the fuse blowing?