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 Power source for electronic tach and/or speedo

 Created by: tmsmith
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 Posted: Jun 20, 2017 10:16AM
Total posts: 7213
Last post: Aug 18, 2017
Member since:Aug 14, 2002
CA
Quote:
Originally Posted by tmsmith
I love the hockey lace idea. I had already used the other style.

It seems my order of misc. small parts from British Wiring is stranded in Houston for the last few days. It was due to be delivered yesterday. Progress is slow. And of course I cannot find parts I ordered a while back...

Sounds like a Canadian solution ( we invented hockey!) Now... which colour? (See image!)

.

"Hang on a minute lads....I've got a great idea."

 Posted: Jun 20, 2017 08:57AM
Total posts: 3620
Last post: Jul 25, 2017
Member since:Jun 23, 2000
US
I love the hockey lace idea. I had already used the other style.

It seems my order of misc. small parts from British Wiring is stranded in Houston for the last few days. It was due to be delivered yesterday. Progress is slow. And of course I cannot find parts I ordered a while back...

 Posted: Jun 20, 2017 02:58AM
Total posts: 8465
Last post: Aug 18, 2017
Member since:Jun 5, 2000
US
Yep, John G. has the square prototype for the oval aux gauge pod I have now.  I still cannot believe he wanted it.  I got the better end of the deal.  He sent me some of his homemade preserves.

Since the car is not original but you have a new loom and want to keep it looking fairly original I have a couple of suggestions.  You can route your new wires inside a couple of different covers.  There is braided wire wrap that looks very much like the original cloth harness cover.  The link below is for some of the small material available through Amazon.  Other sizes and colors are available.
Amazon Link
Apply a little heat shrink tubing to the ends and it looks very good.

However, if you are looking for something more "organic" and that might match your car's harness even better, buy "hockey laces".  You can cut the ends off, run a fair number of wires through, then apply heat shrink over the cut ends to dress the wiring up a bit.  The laces typically have color strips like the original cloth covered looms so you may find a lace that matches the appearance of other wiring in/on the car.  

Hockey Laces Link

Doug L.
 Posted: Jun 19, 2017 04:58PM
 Edited:  Jun 19, 2017 04:59PM
Total posts: 3620
Last post: Jul 25, 2017
Member since:Jun 23, 2000
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Image Gallery
Thanks for the responses, Doug and Murray.

I am actually installing my version of your instrument pod Doug. You sent a photo of yours many years ago and I think John G. ended up with a similar one.

Nick Upton did the fabrication and this is version two. The original version is in our tin wagon and this is close to being installed in the woodie wagon.

The car uses distributorless ignition, so the trigger feed for the tach comes from the ECU.

The picture shows the test fitting before the dash cards go in.

 Posted: Jun 19, 2017 07:20AM
Total posts: 8465
Last post: Aug 18, 2017
Member since:Jun 5, 2000
US
Terry, you said the loom is new.  Look at its end near the distributor.  There should be at least one white/black wire. There may be more.  If there is only one white/black wire it will be short and go between coil (-) and the distributor.  If there is a second white/black wire it will be for a tachometer sense wire.  You can connect that wire at coil (-) and in the cabin connect the other end to your tach's sense input.  This will prevent having to run an extra wire under the bonnet.  However, you will still have to tap into a "dark green wire" circuit for switched, fused power for the tach.  The earth ground should be straightforward leaving only the illumination which you need to splice into a red or red/white wire circuit behind the dash.

Doug L.
 Posted: Jun 18, 2017 01:21PM
Total posts: 3620
Last post: Jul 25, 2017
Member since:Jun 23, 2000
US
Murray:
That is somewhat my concern, I am not a fan of random wires in the engine bay. I am not exactly happy with my relay install for the headlights and horn.

I had been holding off installing the instruments as I had ordered an electronic speedo, but it is not going to make it here in time for MMW, so I am putting the old one back in.

Terry

 Posted: Jun 18, 2017 01:05PM
mur
Total posts: 5639
Last post: Aug 17, 2017
Member since:Nov 12, 1999
The DC motors are stable loads, and the tach draws very little power, I would expect it to be fine; however if you can be tidy about it, that circuit would be ideal to trigger a relay that would then power anything else you add. The real challenge is running any wire alongside the main harness and not having it look out of place.

 Posted: Jun 18, 2017 12:35PM
Total posts: 3620
Last post: Jul 25, 2017
Member since:Jun 23, 2000
US
I am adding an electronic Smiths tach to our 65 Traveller. I have replaced the loom with one from British Wiring.

The fused ignition-on power feed to the voltage stabilizer, windshield wipers, and heater fan looks like it could work for this. Would using this power source cause an issue for the tach with it also supplying two electrical motors?