Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: Grumblebuns on Sunday,September 11, 2022, 10:04:37 AM
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I'm in the process of wiring up my Spal radiator fan and I'd like to maintain the stock wiring color standard as much as possible. The original B/G and Y/G wiring circuit to the fan appears to be 14 wire (equivalent to 18 AWG) which to me is pretty underwired even for the original fan much less for the higher output Spal. I'd prefer to use a 44 strand (equivalent to 12 AWG) wire instead to eliminate any voltage drops. Unfortunately the largest size British Wiring offers in the B/G and Y/G colors are the 28 strand (equivalent to 14 AWG).With the short wire run from the fuse box to the relay, the 28 strand wire probably will not cause a problem. My thought is to run an equivalent "12 AWG" wire is to double up on a 14 strand and a 28 strand to create a 42 strand B/G or Y/G run to the relay. Besides the potential DPO aspect of this, anyone see a technical problem with this?
Joji Tokumoto
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14AWG is good for 15A. How much does the Spal draw?
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And if you do double it, then keeping the right color code sounds like the thing to do.
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I would go with the larger wire size rather than running two wires. Either way it is noticeably non-standard and a single wire with a connection at either end is more reliable than two wires with four.
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Spal recommends either 30 0r 40 amp fuses for their "high performance" paddle style fans, see photo. If I had a clamp on ammeter I would check the running current on the bench but I don't. I ran 12 gauge orange wire for my last radiator fan swap out on another TCS; I'll ponder this further.
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Hate to throw another monkey in the wrench , but have you thought about a fan control kit with a 40amp relay? It can also run dual fans for further cooling ?
This kit has a 12 gauge feeder. I would also stay away from dual wires.
Dakazman
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I just installed my spal fan I just hooked it up to the original fan wiring
Should I be worried
One thing I noticed is the wiring on the spal fan is the same gauge as the original fan so
I don’t see the purpose of doubling or putting bigger wires unless you take the fan apart to change wires in it if it pulls so much power why are the wire so thin
Please let me know what you guys think
I just ran the fan a couple seconds to see if it worked
And noticed where I bought it says 25 amps at 13 volts
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You can’t tell how thick the wire is without cutting off the insulation.
Use an ammeter and measure the current. If it is over 10-ish amps continuous, then you need larger wire — yes it may be “rated” to 15 amps but you need a safety margin.
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You are right Jb I didn’t remove the insulation ,the end of the fan wiring comes with a plug with two
Pins I just used U type connectors but now I’m thinking of cutting the plug off and putting tab connectors so that’s gonna give me the chance to really see what size wires are on the fan and I’ll go from there
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You could also run the fan for 5 minutes and feel the wire. If it is warm, it’s too thin.
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There seems to be a discrepancy on fuse requirements between the Spal website and what is printed on their packaging. The website has a 25 amp fuse requirement while the packaging has a 40 amp fuse. As far as I remember, there was no installation sheet included with the fan however 40 amps seemed a bit excessive to me so I'm tending to believe that the 25 amp fuse requirement is more reasonable.
In my post I stated that the stock wiring (B/G and Y/G) for the radiator fan appears to be 14 strand wire equivalent to 18 AWG. According to a wire amp capacity chart, the amp limit will be less than 10 amps at 4 feet wire length which I suspect will be pretty much at the limit for the stock wire. The Spal off the top of my head looks to be using 14 AWG which will handle 15 amps at 6 feet length.
In regards to your current setup, I don’t have the training or experience to tell you definitely if you’re exceeding the limit for current rating but with a 25 amp fuse requirement for the fan, I suspect you’re very close. The other things to consider is the voltage drop with the smaller than optimum wire size affecting fan speed and heat up of the wiring. You also have to remember that you are using the original 30 amp fuse in the fuse box for protection and not the recommended 25 amp fuse.
At the very least, I would look into running the fan through a relay.
https://www.lotuseuropa.org/LotusForum/index.php?topic=1062.0
https://jascoautomotive.com/automotive-wire-amperage-capacity-chart/
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Doesn’t the stock circuit complete with the temperature switch connecting to ground? As the other half of the circuit, that ground line should also get beefed up to the current rating the power feed gets. Over the years I’ve seen many posts about bigger power feeds and power relays for fans, headlights, and windows. But it just occurred to me that I haven’t seen discussion of increasing the ground line.
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Power in should equal power out, so the ground wire size should equal the number of hot wire(s). Controlling the fan circuit through the Otter switch will reduce the longevity of the switch due the high current arcing during switch operation. That's the reason a relay is recommended to handle the current.
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The rad fan switch controls the fan relay. It is not in circuit with the fan.
There are various motors used in Spal fans. Amp draw ranges from the teens to the forties (!). Boxes can be generic so double check on the Spal website with the actual part number.
High power fans draw more, a lot more, amps on start up. A fan that draws 14 amps continuous might peak above 30 on start up. You can use a fan controller with “soft” start instead of a relay to alleviate this issue. It also is kinder to your alternator and battery.
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I'm trying to remember if the S2s have a radiator fan relay as stock. I know that the TCs do not, the fan is controlled directly off the Otter switch.
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Your correct Grumble, on both .
The tc fan is just looking for a ground to turn on and it doesn’t care where it comes from . It’s up to the temp sensor.
The s2 does have a relay , in the simplified diagram I’m going through shows it without a ton of extra wires . I didn’t finish this drawing because of the ground connector feeding all the front lights . It is one thing I changed to more like the S1B triple front grounds. A,B,and C .
The S1 in my opinion has a better splitting up problems by keeping it simple.
Dakazman
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I have a s2 the fan takes the power from the relay, the wires were not long enough so I made extensionTo test it out ,I’m going to put red and black wires from fan to relay my setups in the picture
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I hate those connectors. They don't make a good connection. They tend to vibrate loose. And they look terrible. Use "W" crimp or solder connectors, especially important with high current loads.
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Didn't know you had a S2, everything I wrote was for a TC. Sorry for the confusion.
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PIDG terminals (https://www.te.com/usa-en/products/brands/pidg.html?tab=pgp-story ) attached with a proper crimp tool (and not the $5.00 POS you can buy at the local auto parts store which most people use) are even approved for aircraft use, and are probably overkill for something like the Europa. Solder terminals in high-vibration locations? If you use the right tool for the job...a good crimp connector will server for decades.
(some I made in the 80s are still fine in radio stations I built...)
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If you want a more permanent connection, Spal offers a fan wiring connector sold by various vendors. A bit on the pricey side.
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While we're at it, does anyone know of a fan soft start controller that just needs the existing temperature switch in the radiator? Every one I have found so far needs its own temp sensor (apparently for the user to set the temperature to control when the fan goes on).
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Bryan, I can't even begin to list the number of times I've been under a dash and had wires pull/ed out off those connectors. Sure, if done properly, they work great. In the field, not the air, they seem not to be installed properly time and time again.
In contrast, the above issues never happen with a "W" crimp.
YMMV
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Bryan, I can't even begin to list the number of times I've been under a dash and had wires pull/ed out off those connectors. Sure, if done properly, they work great. In the field, not the air, they seem not to be installed properly time and time again.
In contrast, the above issues never happen with a "W" crimp.
YMMV
Comes down to using the right parts assembled by the right tool for the job. Or finding someone who knows how to do the job properly, listening, learning, and practicing (thus not earning the "DPO" label). I realize not everyone has had a mentor/expert to learn from (I was lucky to have a number of good wrenches and A&Ps to do my journeyman training under), but there are lots of resources that, once consulted (and testing out on the bench, not under the dash, beforehand), pays dividends down the road.
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I have a s2 the fan takes the power from the relay, the wires were not long enough so I made extensionTo test it out ,I’m going to put red and black wires from fan to relay my setups in the picture
I would just cutoff that end and go for a more environmental splice, with some heat shrink over the splice . you don't need a disconnect there because you have one at the relay.
Dakazman
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That wasn’t the final wiring! I just did this to try out the fan and it really pushes
I went to see directly on the spal website and it says 25 fuse value 13 volts
Isn’t that a bit to much for the 30 amps alternator just wondering
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Is your car running? If so, watch the amp gauge, now turn on fan and watch the draw, you can also load it up and turn on headlights, and run the windows up and down. Is the alternator keeping up?
Dakazman
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It’s not running right now my alternator rotor went for rewinding so I can’t test it now should receive it any day
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A 25 amp fuse is required because of the larger amount of current required to start the fan. Running draw will be much less.
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I decided to pick up a clamp on ammeter and did a current test for my Spal 10" fan. Using an old but fully charged battery with a voltage of 12.7V, The Spal fan used 10.5 amps. This should be well within the capability of a 14 AWG wire 5' in length. With an alternator keeping the battery at plus 13V, the amps should be slightly lower. My mid grade meter does not have a peak read feature so was unable to read starting current. I will still plan on using 12 AWG wire for my TCS.
An oh by the way, the Spal literature does not provide the power requirements but if you plug in my numbers to the power formula, it comes out to 133 watts. Someone correct me if I'm wrong.
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I installed my rebuilt alternator 12/30 Motorola let my engine idle but had forgotten to reconnect the power to the fan relay so I was waiting for the fan to go on so it got a bit hot
so I connected it and it took three minutes to get it cooled down enough for the fan to stop
My otter switch is 82 77 Celsius probably would have taken less time if my wire would have been connected I touched the wires and they were cold I’m gonna try again tomorrow cause I don’t want to bother the neighbours!!
I had my multimeter on my battery
At idle 13.76 when fan went on 12.93