Keep popping fuse #19 - LotusTalk - The Lotus Cars Community
 3Likes
  • 2 Post By Roundabout
  • 1 Post By Roundabout
 
LinkBack Thread Tools Display Modes
post #1 of 13 (permalink) Old 06-15-2018, 10:59 AM Thread Starter
user /tron
 
RideMooch's Avatar
 
Join Date: Jul 2006
Location: Hillsborough, NC
Posts: 880
Keep popping AC fuse #19

So my AC hasn't worked in about a year (fan works at all speeds, engine revs increase with AC button press, but blows warm air), but since I basically only drive it with the top off or on the track, I hadn't tried chasing it down until now since I'm considering selling the car.

On my first pass to fix it, I found that the fuse #19 (under front access panel - "AC comp relay and rad fan 2 fast") was blown. Replaced that, and refilled teh refrigerant with a can from autozone, and it worked great! blew cold air and did that for a couple on-off cycles. Drove the car to work w cold air and when I went to leave work it was blowing hot again right from the moment I turned the car on. Fuse #19 is popped again.

So knowing that the AC works great when the fuse is intact, what keeps popping my fuses? Where do I start? the radiator fan connections? is there a ground on the compressor somewhere? the pack of connections in the passenger wheel well?

Thanks for any help - I'm decent with a wrench, but terrible with electrical stuff.

~Matt
'06 CO Elise
'17 Toyota 4Runner TRD Pro, cement grey
'16 VW GTI, Wifey's ride
Past toys: '02 WRX | '06 STI | '14 Subaru BRZ

Last edited by RideMooch; 06-20-2018 at 12:05 PM.
RideMooch is offline  
Sponsored Links
Advertisement
 
post #2 of 13 (permalink) Old 06-20-2018, 12:09 PM Thread Starter
user /tron
 
RideMooch's Avatar
 
Join Date: Jul 2006
Location: Hillsborough, NC
Posts: 880
Anyone? Bueller?

~Matt
'06 CO Elise
'17 Toyota 4Runner TRD Pro, cement grey
'16 VW GTI, Wifey's ride
Past toys: '02 WRX | '06 STI | '14 Subaru BRZ
RideMooch is offline  
post #3 of 13 (permalink) Old 06-20-2018, 12:23 PM
Registered User
 
Join Date: Nov 2015
Location: massachusetts
Posts: 1,907
Well, no idea.

Where l would start is the wiring diagram.

look at everything that connects to that fuse and try to figure out where those wires are. They are color coded in the diagram, so it really isn't rocket science.

If I understood the interaction between the way the AC fires fans and the cooling I might be of more help.

So off the top of my head things in that system[ I am not looking at a diagram]

AC compressor
Fan
AC control thermostat widgets
switch pack module

only thing I have seen that routinely dies is the switch pack module.........I would think the car might run hot if the fan was bad...............
exigegus is offline  
 
post #4 of 13 (permalink) Old 06-20-2018, 12:51 PM Thread Starter
user /tron
 
RideMooch's Avatar
 
Join Date: Jul 2006
Location: Hillsborough, NC
Posts: 880
Quote:
Originally Posted by exigegus View Post
Well, no idea.

Where l would start is the wiring diagram.

look at everything that connects to that fuse and try to figure out where those wires are. They are color coded in the diagram, so it really isn't rocket science.

If I understood the interaction between the way the AC fires fans and the cooling I might be of more help.

So off the top of my head things in that system[ I am not looking at a diagram]

AC compressor
Fan
AC control thermostat widgets
switch pack module

only thing I have seen that routinely dies is the switch pack module.........I would think the car might run hot if the fan was bad...............
Thanks. My understanding (which is probably wrong) is that if the switch pack module went bad the cabin fan speeds wouldnt all work, but mine do; fan blows fine lo/mid/hi. Maybe I misunderstood that.

~Matt
'06 CO Elise
'17 Toyota 4Runner TRD Pro, cement grey
'16 VW GTI, Wifey's ride
Past toys: '02 WRX | '06 STI | '14 Subaru BRZ
RideMooch is offline  
post #5 of 13 (permalink) Old 06-20-2018, 01:43 PM
Registered User
 
Join Date: Apr 2018
Location: Elizabeth City, NC
Posts: 127
I just looked at the schematic briefly and it looks like fuse 19 deals with the AC compressor circuit
Catsailr27 is offline  
post #6 of 13 (permalink) Old 06-20-2018, 03:24 PM
Registered User
 
Jetblast's Avatar
 
Join Date: Nov 2012
Location: Central Iowa
Posts: 24
Garage
Fuse F19 supplies power for the high-speed circuit on the radiator cooling fans as well as power for fuse C4 which provides power for the A/C compressor clutch. It would be my guess that the source of the problem is somewhere in the radiator cooling fan circuit. During normal operation when the engine temperature requires it, the ECU will energize CONT. RLY 3 to start cooling fan #1 (which is powered by fuse F14). When the A/C is turned on, CONT. RLY 1 & 2 energize so both radiator cooling fans will run at full-speed, powered by fuse F19.

The difference in the cooling fan run cycles (A/C on vs A/C off) is that cooling fan #2 runs with the A/C on, but not when the A/C is off, the run cycle of the fans is also higher. Chances are that the #2 fan motor is causing you the problems, but due to the increased fan run-time cycle when the A/C is on there is a small chance it could still be the #1 fan motor. It could also be a connection issue so don't forget to keep your eyes open for that.

I hope this helps.
Attached Images
 

2005 Ardent Red Elise, Gut Sport wing & splitter, custom diffuser, Sector111: DSBrace, gPan3, subStuffy2, Larini Sport muffler, decat pipe, Schroth Racing 5 pts, wheel studs, Team Dynamics 1.2 with Hoosier A6s, Koldflash 200 ECU flash, BOE rear clam hinge, BC Racing single adjustables, Hawk pads, SS Brake Lines, HID lights, custom tail and high mount brake light...and much more...
Jetblast is offline  
post #7 of 13 (permalink) Old 06-20-2018, 04:30 PM
Registered User
 
Roundabout's Avatar
 
Join Date: Jun 2013
Location: California
Posts: 893
Based on what @Jetblast said, you could disconnect cooling fan 2 and replace Fuse 19 and see if that solves the issue for you. This would be as a test, not a permanent solution. My instinct tells me that driving at speeds faster than 35 mph should make the fan unnecessary.
RideMooch and Jetblast like this.
Roundabout is offline  
post #8 of 13 (permalink) Old 06-20-2018, 05:01 PM
Registered User
 
Roundabout's Avatar
 
Join Date: Jun 2013
Location: California
Posts: 893
Incidentally, if you have a auto-dismantler, Pick-N-Pull or whatever nearby, they will often sell handfuls of fuses for $5 or less. Diagnosing a fuse issue can start to cost money paying WalMart prices.
RideMooch likes this.
Roundabout is offline  
post #9 of 13 (permalink) Old 06-21-2018, 04:37 AM
Registered User
 
Join Date: Nov 2015
Location: massachusetts
Posts: 1,907
if I look at the diagram, fan 2 is certainly the main suspect.

in low the fans are wired in series, both running slow, and gets power from f14[cont relay 3 enabled]
in high, they are both running in parallel but getting power from different fuses, fan one continues to get power from F14 and now gets ground independently, instead of through fan 2, Fan 2 gets power from f19 and always has its own ground source.

The problem could be within the switch pack module, which is easier to change, and about 150 bucks. A 20 amp short in the switch pack module I would think would make some heat. And a fan drawing slightly higher current that blows a fuse over time seems more likely

If the SWP has never been changed, the newer one has an update that prevents ECU glitches when the AC is on, so it is not a complete waste of money to try that
exigegus is offline  
post #10 of 13 (permalink) Old 06-21-2018, 05:19 AM
Registered User
 
Join Date: May 2018
Posts: 27
You can check the radiator fans on idle. Low speed comes on at engine temp about 90C and high speed at 100C (Don't quote me on those figures).

It might also be a sticky clutch on the compressor. Try removing the compressor relay and see if F19 still blows.

DC

2010 Lotus Evora
2007 Mitsubishi L200
2005 Porsche Cayenne 4.5 V8
2004 Porsche Boxster 3.2S
DonkeyDave is offline  
post #11 of 13 (permalink) Old 06-21-2018, 05:23 AM
Registered User
 
Join Date: Nov 2015
Location: massachusetts
Posts: 1,907
while possible I feel like the compressor clutch would be unlikely as it has its own fuse, and it blowing the larger fuse without blowing the smaller seems odd, unless the fuse has the wrong value in it
exigegus is offline  
post #12 of 13 (permalink) Old 10-03-2018, 06:38 AM Thread Starter
user /tron
 
RideMooch's Avatar
 
Join Date: Jul 2006
Location: Hillsborough, NC
Posts: 880
Ok, coming back to this. several have supported a fan connection issue....how do I get to that fan? do I need to take the whole clam off to access it (please no)?

~Matt
'06 CO Elise
'17 Toyota 4Runner TRD Pro, cement grey
'16 VW GTI, Wifey's ride
Past toys: '02 WRX | '06 STI | '14 Subaru BRZ
RideMooch is offline  
post #13 of 13 (permalink) Old 10-03-2018, 07:46 AM
Registered User
 
Join Date: Nov 2015
Location: massachusetts
Posts: 1,907
On the Elise you can get in through the grille, some of the wiring might be hidden with the clam on tho
exigegus is offline  
Sponsored Links
Advertisement
 
Reply

  LotusTalk - The Lotus Cars Community > Lotus Discussions > A/C, Heating and Ventilation

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the LotusTalk - The Lotus Cars Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome