924/931/944/951/968 Forum
Sponsored by:
Sponsored by:

No, car is not going 180mph (speedo problem)

Old 07-04-2019, 10:34 PM
Christopher Zach
Rennlist Member
Thread Starter
Join Date: Mar 2003
Location: Washington DC
Posts: 627
Likes: 0
Received 6 Likes on 4 Posts
Default No, car is not going 180mph (speedo problem)

Weird problem that has cropped up: The speedometer goes from zero to pegged when you turn on the key. Doesn't come back, but isn't stuck.

How is the speedometer connected to the speed sensor, and which sensor is feeding it? Looking at the wiring diagrams is not helping too much, they're a bit of a mess.Is it fed from the DME?

I'm thinking a wire may be shorting to +12v and throwing the speedo to max. Thoughts?

Christopher Zach is offline  
Old 07-07-2019, 02:04 PM
Join Date: May 2019
Location: Nor Cal
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts

I think I got a similar problem on my 944 except mine is mostly the temperature gauge and sometimes the RPM gauage will be stuck all the way at the bottom. Sometimes a bit of percussive maintenance (slap the dash with my hand) will fix the RPM gauge but doesn't always get the Temp Gauge back from stuck at full. If I turn the key off the needle will fall back to the bottom, once I turn the key back on it spikes immediately to the top. Even cold.

I've replaced the entire cooling system, all new switches and it still does this.

I haven't fixed mine yet but I know what is causing mine. Not sure if this is what is happening to yours but this is how I know mine is being caused by the instrument panel connections; reach under the dash with the key on and try to gently wiggle one of the gauge cluster electrical connectors, when I do this to the left side electrical connection my temp gauge drops back down from all they way high to perfectly in the middle, most of the time it will work itself back to being stuck at high but this tells me where the problem lies.
JackHB is offline  

Thread Tools
Search this Thread

Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: