The Lotus Cars Community banner

1 - 20 of 32 Posts

·
Registered
Joined
·
109 Posts
Discussion Starter #1 (Edited)
so I did a rear window delete and decided to put a fan on my deck lid, in believe it is 13.6 v and would like to connect it directly into the rear window defroster wiring so I can turn it on/off by using the rear defroster switch ..( put it to use since window is gone lol )..is the 13.6 v too high of power to run thru those wires ? also theres 2, one on left side and one on right of the trunk lid ,what exactly are they fir
 

Attachments

·
Registered
Joined
·
597 Posts
Wires can be decoded by comparing their color to the wiring diagram.

Voltage is not the issue; amperage might be.

Not that you asked, but installing a fan that way is probably not going to do anything at all for you.
 

·
Registered
Joined
·
109 Posts
Discussion Starter #3
Wires can be decoded by comparing their color to the wiring diagram.

Voltage is not the issue; amperage might be.

Not that you asked, but installing a fan that way is probably not going to do anything at all for you.
ok where can i find this diagram ? and its sucking the air out why dont you think it would help ?
 

·
Acme Super Moderator ** The Enforcer **
Joined
·
7,594 Posts
ok, lol wow tough crowd huh :shrug:
You asked a question. I answered it. No need to dance around the truth, unless you prefaced your question with that requirement. It isn't personal, I just tend to cut to the chase.

San
 

·
Registered
Joined
·
824 Posts
It will probably be useful while you're sitting still in traffic on a hot day. If you're moving, it will likely impede airflow rather than improve it. There's likely no solution to that. If you want more cooling, you'd want to add more intake air area, but it'd probably require reasonably complicated modeling to do so without harming the current airflow.
 

·
Illegal Alien
Joined
·
5,153 Posts
1) How many amps is the fan, should list on the motor?
2) 13.6 V is your nominal car voltage output from the alternator so will be ok but to be safe on average loads take fan stated Amps x 13.6/12.0 = circuit Amps , this must be less than the fused value of the Defrost circuit.
3) Why?? as stated above may only help airflow in stop and go.
4) Why?? what are you trying to solve, if the car is not over heating you don't have a problem.

I love where it gets to 110F in the summers, I don't have a problem and my car even has engine oil readings and manual transmission low and high oil temp warnings that have never activated.

Focus on problem solving of issues you have, don't create new ones.
 

·
Registered
Joined
·
230 Posts
The defrost circuit is fairly high current, 25a I think, but you should still connect the fan thru a relay if you decide to go through with this.
 

·
Premium Member
Joined
·
1,514 Posts
Yep, 25A circuit there. And it's already relayed by the HRS Relay, so you could probably run the fan off that if you so choose.

Here's the diagram. One of the terminals is ground, the other is your +12V.
 

Attachments

·
Registered
Joined
·
248 Posts
Apologies for being negative, but when the car is moving, that fan is going to restrict air egress. With an open louvre, the speed of air over the car will create a pressure differential which will drag air from the engine compartment. No fan needed.

At rest the fan will drag air in from the edges, including air from outside, so now you have partially blocked even the exit routes around the fan. Unless you have an overheating problem, remove it. If you have an overheating problem rethink your cooling solution. Open up air ingress at the bottom of the engine compartment as well as thinking about how to funnel hot air out.
 

·
Registered
Joined
·
109 Posts
Discussion Starter #14
thanks for the constructive advice fellas, I thought about doing it because when in traffic in the hotter days i hate seeing the temperature go above half. theres no issue when driving so i dont think the fan will impede more than help , but since i already have it setup and thanks to you're help i now know i can safely connect to the defroster switch, next time i take it out ill see if it makes a difference in traffic .
 

·
Registered
Joined
·
166 Posts
Hey Card0lan,
I think you're being creative and sharing some new ideas, thanks for that. Just replacing the glass with the louvered cover is going to help ventilate heat from the engine compartment; and it's true what these guys are saying - when you're moving, air is channeled into the engine compartment from the vent openings just behind the doors (especially the passenger side, the driver side usually has the air intake to the motor). If the fans are spinning, I don't think they're going to create a big restriction; and in traffic, they could be useful.
The voltage rating of the fans just tells you the approximate voltage of the circuit they should be used in, and a car (when running) usually produces around 14-14.4 volts, so the fans should work well in that circuit. The rated amperage is the amount of current that the fans will draw when under load, and that just helps you determine the circuit they can be attached to. More current draw produces more heat, so circuits are protected by fuses so the current flow will be interrupted (fuse melts) before the rest of the circuit can get too hot.
Car manufacturers try all kinds of ideas when they're developing better cars - some become world famous, and others end up in the trash can. Keep us posted on how you feel this worked out for you.
 

·
Registered
Joined
·
390 Posts
Remember the heated rear screen is on a timer... 10 minutes or so, you'd have to keep on switching it on....
 

·
Premium Member
Joined
·
1,514 Posts
I mean, it can't be entirely useless, otherwise Porsche wouldn't have put an unducted one on the 911 lids right? ;)
 

·
Premium Member
Joined
·
1,514 Posts
Remember the heated rear screen is on a timer... 10 minutes or so, you'd have to keep on switching it on....

@itscard0lan

And that circuit also controls the side mirror heaters. If I were the one making this change, I'd probably tap into the engine bay cooling fan circuit/relay so that it automatically comes on when stopped and the temp is above the threshold.

That circuit is only protected at 10A though, so it would depend on your fan's current requirements. You could always relay it separately though.
 

Attachments

·
Registered
Joined
·
597 Posts
Porsche wouldn't have put an unducted one on the 911 lids
If you really think that Porsche decklid fan is not ducted, you haven't looked very closely at the engine compartment of a 911.

Will be interesting to see what OP thinks about his fan install. How will it be determined whether it is successful, or indeed is having any material effect?
 
1 - 20 of 32 Posts
Top