Results 1 to 2 of 2

Thread: Thermo-time Switch (911-617-117-01 / VDO 36/3/4)

  1. 06-23-2024, 05:44 AM #1
    McOtto
    McOtto is offline
    Senior Member McOtto's Avatar
    Join Date
    Apr 2023
    Location
    Denver, CO
    Posts
    248

    Thermo-time Switch (911-617-117-01 / VDO 36/3/4)

    [Edit - Part no. should be 911-617-117-00]

    Does anyone know what typically fails in the thermo-time switch? I have tested a couple of used ones and think the contacts may be fused in both???

    I say that because using the test method shown in the attached diagram (let me know if it has any flaws), the W terminal grounding circuit shows good. When I apply 12 volts to the G terminal heating element, it does not open the contact (W stays grounded). Also used a hair dryer to heat up the switch body. Same thing - W stays grounded indicating the bi-metal strip is not flexing as it should and the contact is staying closed, not opening.

    There is a very high probability I am missing something obvious and fundamental. Let me know if I am.

    Used switches may be readily available for a reason. Before I invest in a new one, just hoping someone might be able to identify any errors in my test method and shed some light on what typically fails.

    Thank you!
    Attached Images Attached Images  
    Last edited by McOtto; 06-23-2024 at 06:46 AM.
    1972 911T Targa
    1985 911 Carrera (with circa 1988 RUF 3.4L 260 hp DIN Engine Kit)
    Reply With Quote Reply With Quote
  2. 06-23-2024, 05:45 PM #2
    McOtto
    McOtto is offline
    Senior Member McOtto's Avatar
    Join Date
    Apr 2023
    Location
    Denver, CO
    Posts
    248
    @boyt911sc, who is a frequent contributor to the Pelican forum, set me straight on Thermo-time switch test wiring. Please disregard my previous sketch. This one works. I tried it.

    It case it helps others, also attached is the wiring diagram sketch I put together to help me understand how the cold start fuel enrichment system works. If anyone sees any errors or need for clarifications, please let me know so I can issue a revision. Thank you!
    Attached Images Attached Images   
    1972 911T Targa
    1985 911 Carrera (with circa 1988 RUF 3.4L 260 hp DIN Engine Kit)
    Reply With Quote Reply With Quote
« Previous Thread | Next Thread »

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Forum Rules


Message Board Disclaimer and Terms of Use
This is a public forum. Messages posted here can be viewed by the public. The Early 911S Registry is not responsible for messages posted in its online forums, and any message will express the views of the author and not the Early 911S Registry. Use of online forums shall constitute the agreement of the user not to post anything of religious or political content, false and defamatory, inaccurate, abusive, vulgar, hateful, harassing, obscene, profane, sexually oriented, threatening, invasive of a person's privacy, or otherwise to violate the law and the further agreement of the user to be solely responsible for and hold the Early 911S Registry harmless in the event of any claim based on their message. Any viewer who finds a message objectionable should contact us immediately by email. The Early 911S Registry has the ability to remove objectionable messages and we will make every effort to do so, within a reasonable time frame, if we determine that removal is necessary.