Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Low speed radiator fan only works with a/c on

Recommended Posts

Why do you want it to be the DME?  There are a lot of other factors in play, coolant sensor, ambient air temp sensor, interior air sensor, settings on the HVAC system, engine compartment temp sensor.  Are both fans acting the same, i.e., no low speed?  It is normal for both of the low speed fans to turn on when AC is on.  There are certain conditions that have to be met before the low speed fans kick in without the AC on.  I'll try to look them up.  Got Durametric?  You can test the fans with Durametric.

Link to comment
Share on other sites

Thank you!

Both fans kick on low with AC

without AC, goes to 103c before high comes on. 


Im not hoping it’s DME at all. 

I think I just need some guidance to check continuity between DME and low speed relays, and I’d love any and all advice. 


Just replaced the Water temp sensor. No change. 

Edited by JJBravo
Link to comment
Share on other sites

  • 2 weeks later...

Low speeds come on with ac. 

If ac off, lows don’t come on at all, but high speed does at 103c


Installing center rad now and determined to test continuity from dme to relay

Edited by JJBravo
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.