General Miata Chat A place to talk about anything Miata

Engine starts but no signal to the dash?

Thread Tools
 
Search this Thread
 
Old 03-11-2009, 11:45 AM
  #1  
Newb
Thread Starter
 
djkompressor's Avatar
 
Join Date: May 2007
Posts: 44
Total Cats: 0
Default Engine starts but no signal to the dash?

Hey guys just swapped in a new motor. Motor fires up but im not getting any RPM's or anything on there. Not even my E brake light. But they do light up when i turn the headlights on. Is there a fuse for that? A buddy of mine said it could be my ECU?
djkompressor is offline  
Old 03-11-2009, 11:47 AM
  #2  
I'm Miserable!
 
johnhanson's Avatar
 
Join Date: Mar 2009
Posts: 56
Total Cats: 0
Default

Hook up the grounds you forgot to hook up.

/thread.
johnhanson is offline  
Old 03-11-2009, 11:54 AM
  #3  
Newb
Thread Starter
 
djkompressor's Avatar
 
Join Date: May 2007
Posts: 44
Total Cats: 0
Default

grounds are hooked up. It doesn't start unless they are...
djkompressor is offline  
Old 05-04-2009, 08:27 AM
  #4  
Newb
 
Skuzzle's Avatar
 
Join Date: Feb 2009
Posts: 40
Total Cats: 0
Default

i need to know this also.
Mine packed up on a track day. Turn signals, dials and reverse lights all packed up together.

Checked all fuses and no issues there.

Beggining to run out of ideas.

Definately sounds identical though.
Skuzzle is offline  
Old 05-04-2009, 08:43 AM
  #5  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,019
Total Cats: 6,587
Default

Depends on year of car.

'90 to '93 there's a yellow/blue wire going from the igniter to the tach and diagnostic box.

'94-'95.5 (cars with four wire coils) the wire is black/white and comes off both coils in parallel.

'95.5-'97 the black/white wire comes from the ECU.

'99-'05 it's a green/orange wire from the ECU.
Joe Perez is offline  
Old 05-04-2009, 08:50 AM
  #6  
Newb
 
Skuzzle's Avatar
 
Join Date: Feb 2009
Posts: 40
Total Cats: 0
Default

does this wire (dependant on year) have anything to do with the turn signals and fuel gauge etc though (and reverse light)
Skuzzle is offline  
Old 05-04-2009, 09:04 AM
  #7  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,019
Total Cats: 6,587
Default

Yes. Those two signal are modulated onto the tach wire using a simple FSK algorithm. At the dash, a low-pass filter strips out the turn signal/fuel gauge signal for the tachometer feed, and a simple DC blocking cap is used to feed the FSK signal into a decoder which then derives the fuel and turn indicator data.
Joe Perez is offline  
Old 05-04-2009, 09:12 AM
  #8  
Newb
 
Skuzzle's Avatar
 
Join Date: Feb 2009
Posts: 40
Total Cats: 0
Default

im not even gunna lie to you that I understand a word of that, but at least I know what wire too look at first.

Thanks
Also oil pressure guage and temp gauge dont work so im assuming this will probably be the same wire too.

Cheers I'll go look later
Skuzzle is offline  
Old 05-05-2009, 12:55 PM
  #9  
Newb
 
Skuzzle's Avatar
 
Join Date: Feb 2009
Posts: 40
Total Cats: 0
Default

could this be a problem with my megasquirt wiring as i remember needing to jump some pins with a resistor for the rev counter to work.. would this stop the other dials working too ??
Skuzzle is offline  
Old 05-05-2009, 05:12 PM
  #10  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,019
Total Cats: 6,587
Default

Originally Posted by Skuzzle
im not even gunna lie to you that I understand a word of that, but at least I know what wire too look at first.
Just so we're clear, every word of my last post was complete BS. The black/white tach wire has absolutely nothing at all to do with anything except the tach. Not the brake lights, not the OPG, not the blinker fluid level. Nothing.
Joe Perez is offline  
Old 05-05-2009, 05:13 PM
  #11  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,019
Total Cats: 6,587
Default

Originally Posted by Skuzzle
could this be a problem with my megasquirt wiring as i remember needing to jump some pins with a resistor for the rev counter to work.. would this stop the other dials working too ??
Until you tell us what year your car is, that question cannot be answered as it's changed over the years. Put it in your damn sig.
Joe Perez is offline  
Old 05-05-2009, 08:28 PM
  #12  
Elite Member
iTrader: (21)
 
rleete's Avatar
 
Join Date: Jun 2007
Location: Rochester, NY
Posts: 6,593
Total Cats: 1,259
Default

Originally Posted by Joe Perez
Just so we're clear, every word of my last post was complete BS.
Joe, you are far too good at pseudo technobabble. I spend a minute or two trying to decipher that post!
rleete is offline  
Old 05-06-2009, 02:57 AM
  #13  
Newb
 
Skuzzle's Avatar
 
Join Date: Feb 2009
Posts: 40
Total Cats: 0
Default

sorry, its a 94 jap import 1.8
Skuzzle is offline  
Old 05-06-2009, 03:15 PM
  #14  
Junior Member
 
gaius49's Avatar
 
Join Date: May 2009
Location: Bay Area, CA and Portland, OR
Posts: 99
Total Cats: 0
Default

I had a similar problem after I changed my clutch. I oopsed the neutral and reverse sensors which caused a fuse in the driver footwell to go out. Just a thought.
gaius49 is offline  
Old 05-07-2009, 04:22 AM
  #15  
Newb
 
Skuzzle's Avatar
 
Join Date: Feb 2009
Posts: 40
Total Cats: 0
Default

unfortunately i've checked all the fuses and all are good
Skuzzle is offline  
Old 10-17-2009, 03:55 PM
  #16  
Newb
 
petrol's Avatar
 
Join Date: Apr 2008
Location: Arlington, TX
Posts: 43
Total Cats: 0
Default

bump?

i have the same problem... only mine wont start either. My Haltech shows an RPM signal but the dash tach doesnt move at all. I'm making a new a post though (hijacks be damned)
petrol is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
shooterschmidty
Engine Performance
8
09-30-2015 10:28 PM
zephyrusaurai
Meet and Greet
2
09-28-2015 10:59 PM
viriiguy
General Miata Chat
5
09-28-2015 07:39 PM



Quick Reply: Engine starts but no signal to the dash?



All times are GMT -4. The time now is 09:11 PM.