Hi all,
Appreciate that this topic has been posted many times but unfortunately I was unable to figure it out from them 
I bought my Elan last year and the tacho wasn’t working. I believe this was because they had changed the distributor to an Aldon electronic unit.
I’ve recently got the tacho restored/converted and I’m now trying to refit it (whilst fitting a new dashboard at the same time 
)
However, I’m uncertain about which wires go into which connections.
I’ve attached some photo’s of the old vs new tacho, and the various wires I have.
The old one (first photo) has 2 bullet connections, with the female connection connected to the coil. The male was connected from the ignition. Both of these are blue/white in colour, although I believe they should really be white only.
The new rev counter only has the female one left (second photo).
My thinking is that this should still come from the coil. I’m unsure where the ignition one should go to though?
Some of the posts I’ve read on here discuss that you should loop this one with another white, but there is nothing to loop it to?
I’ve attached some photos of the wiring as well (hopefully they are clear enough). There is one white wire not going anywhere, but this is jus coming from the loom so not sure if I need to do anything with it.
If I’m unable to work this out I will need to get a mechanical electrician in
Obvious question really, what instructions did the person who converted it give you?
regards
Mike DHC Sprint
Hi Chris
According to those instructions you have to make 3 connections:
1 Main body spade connection +ve ignition feed, that will be the same one that came off that connection before. That is a green wire but I can’t see it in your photos.
2 Bullet connection -ve side of coil. It should be a white wire coming from the coil. You said it was white/blue before. If that is shown in your photo it is linked to other white wires and looks like a PO has used the wrong colour wire. White/blue is normally a headlight connection. If it went to the tacho before use it again.
3 Body of gauge - black earth -ve connection. Your photo shows the earth connection roughly in the centre of the back of the tacho has been painted black. This needs to be scraped off if you use a push on spade. Alternatively you appear to have a black earth connection with 3 wires going to a ring connector, that can be trapped under one of the knurled nuts retaining the tacho to the dash.
Hope that helps, do you have a wiring diagram? do you have a multimeter?
Mike
Hi Mike,
-
I have a green wire, this was in a block of spade connections on the back (3 green).
-
There one coming from the coil, the picture is called ‘White from Coil’. It is blue and white so totally the wrong colour but I have traced it back to the coil.
The blue/white wire in the other photo (the photo is called ‘white junction’) was the one in the male connection in the old tacho. I believe I no longer need this going into the tacho so can remove it from the white junction block altogether?
- Yes, the old blacks went to the knurled nuts retaining the dash so I was going to put it there again.
Yes I have a wiring diagram that I have found online. My confusion was around the fact that one of the ‘white’ wires would no longer go into the tacho. If I am correct with regards to point 2, I believe that would resolve that issue?
I also have a multi-meter
Hi Chris
2 You need the one you know comes from the coil and that’s it.
Go for it. Report back.
Mike
Thanks Mike. I’m going to try on the weekend (hopefully), but I will reply back on this post as soon as i do.
Chris
