tach problems on S2 and update to previous post

PostPost by: tvacc » Sat Jan 03, 2015 8:17 pm

Hi guys

Trying to figure out why tach is not working on the pos ground S2 I am working on. And I want to update you guys on the "motor rocking" post. First, it is the vacuum headlight system that is causing the issues. I blocked it off and motor runs fine. Don't know what the issue is yet, but will let you know.

My issue at the moment is that the tach is not working. I will post a picture right after i write this in the next post from my mobile phone. There is one connector that has no connector on it. I think it is power but not sure. Can someone look at it that is familiar with lucas tachs and let me know. My other Elan is in storage about 45 min from where I am so I cannot look at that car. Let me know what the wiring should be on the back of this.

Thanks in advance
Tony Vaccaro
LOONY (Lotus Owners of New York)
http://www.lotusowners.com
Drive Fast Take Chances
ElanGTS, 93 Caterham, 05 Elise,
99 Elise190, 05 Elise, 2005 MiataSpeed Turbo
User avatar
tvacc
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1161
Joined: 24 Dec 2003

PostPost by: tvacc » Sat Jan 03, 2015 8:24 pm

Here is the rear of the tach
Attachments
WP_20150103_004.jpg and
Tony Vaccaro
LOONY (Lotus Owners of New York)
http://www.lotusowners.com
Drive Fast Take Chances
ElanGTS, 93 Caterham, 05 Elise,
99 Elise190, 05 Elise, 2005 MiataSpeed Turbo
User avatar
tvacc
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1161
Joined: 24 Dec 2003

PostPost by: Ang10l » Sat Jan 03, 2015 8:49 pm

Hi,

There are two connections missing.

Depends on whether your car is Positive or Negative Earth.
My car is Positive earth and has a negative connection connected to the flat spade connector. The mounting nut has the Positive connected to it. (Reverse if you have converted to negative earth)
Ang10l
New-tral
 
Posts: 4
Joined: 26 Dec 2012

PostPost by: billwill » Sat Jan 03, 2015 11:37 pm

Yes that spade connector carries the power for the electronics and the case is the other connector and goes to ground.

When converting from original +ve earth to -Ve earth car the connections inside the tacho need to be swapped over. Presumably if your car has always been +ve Earth, the wires are in their original state inside.

The power to the spade connector should come from a circuit after the ignition switch, but NOT via the voltage regulator (which is often fastened to the holding nuts of either the tacho or the speedo for convenience.)
Bill Williams

36/6725 S3 Coupe OGU108E Yellow over Black.
billwill
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 5060
Joined: 19 Apr 2008

PostPost by: tvacc » Sun Jan 04, 2015 1:05 am

Thanks guys. I had to leave the car before I got a chance to look for an answer here. It is what I guessed it would be. I will take another crack at this next weekend. Let you know what I find.
Tony Vaccaro
LOONY (Lotus Owners of New York)
http://www.lotusowners.com
Drive Fast Take Chances
ElanGTS, 93 Caterham, 05 Elise,
99 Elise190, 05 Elise, 2005 MiataSpeed Turbo
User avatar
tvacc
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1161
Joined: 24 Dec 2003

PostPost by: tvacc » Sun Jan 04, 2015 1:16 am

I would like to say one quick thing. You guys are great. What a bunch of nice, knowledgeable, helpful people are part of this group. I have been messing around with Lotus cars for most of my life. I am in my 60's and I have had dealings with other car marque people. Hardly anyone is like Lotus folk. I have met some that are but don't want to get into particulars.Thanks again.
Tony Vaccaro
LOONY (Lotus Owners of New York)
http://www.lotusowners.com
Drive Fast Take Chances
ElanGTS, 93 Caterham, 05 Elise,
99 Elise190, 05 Elise, 2005 MiataSpeed Turbo
User avatar
tvacc
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1161
Joined: 24 Dec 2003

PostPost by: twincamman » Sun Jan 04, 2015 6:53 am

Tony just a thought but to get rid of the vacuum operated head light system Fiero headlight motors should fit and are at the wreckers cheap. Snap the covers up and downright smartly.......Ed
dont close your eyes --you will miss the crash

Editor: On June 12, 2020, Edward Law, AKA TwinCamMan, passed away; his obituary can be read at https://www.friscolanti.com/obituary/edward-law. He will be missed.
User avatar
twincamman
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3175
Joined: 02 Oct 2003

PostPost by: tesprit » Sun Jan 04, 2015 6:38 pm

I agree with the others that the power and ground (earth) wires are not connected so hopefully you can find them dangling loose in the area around the tach. When you find them, be sure to check them for proper power and ground before you reconnect them. The missing tach wires should not fall off by themselves (especially the ground wire with its ring connector) so make sure that there isn't some reason that they are presently disconnected. I see some light green wires in the lower right of the photo that do not appear to be OEM and for sure their connectors are not so someone has already been messing with the wiring. I would hate to see you burn up your tach or worse yet start an electrical fire under the dash.

Dan
'66 Elan S2
'05 Lotus Elise
'96 Ferrari F355 GTS
tesprit
Second Gear
Second Gear
 
Posts: 71
Joined: 13 Sep 2007

Total Online:

Users browsing this forum: No registered users and 40 guests