Tachometer wiring

horse · Post by **horse** » Sat Mar 25, 2023 10:38 am

How would you wire up a Tacometer to the M38?
I have the full waterproof 24v system.
I notice the Plug part number 73748888 on the Auto-Lite Distributor cover assembly could be removed and gives access to the coil I think?
I would like to set the tick over a bit more accuratly, I have been using a inexpensive Laser type gun on the Crankshaft nut which works okay but fluctuates a lot.
It will not be a permanent fixture just used for tuning up.
Any ideas would be appreciated.
Horse.

RonD2 · Post by **RonD2** » Sat Mar 25, 2023 10:54 am

Hi Horse,
I think having one of these 24V military adapter kits would solve your question.

http://willysmjeeps.com/v2/modules.php? ... dapter+kit

http://willysmjeeps.com/v2/modules.php? ... ht=adapter

Good luck!

horse · Post by **horse** » Sat Mar 25, 2023 11:06 am

Thanks Ron, that would be a nice kit to have.
Any other way around the problem until one pops up at a reasonable price?
Horse.

Post by **wesk** » Sat Mar 25, 2023 11:06 am

Same way the Army did.

These adapters can be used easily with both military test sets and civvy test sets. Just follow the directions for test connections of the Dwell/Tach you are using and employ the appropriate military harness adapter. Same with timing lights and coil test sets.

Post by **wesk** » Sat Mar 25, 2023 11:11 am

Horse said:

Any other way around the problem until one pops up at a reasonable price?
Horse.

Just use old harness parts and plugs and build your own adapters.

horse · Post by **horse** » Sat Mar 25, 2023 11:13 am

Thanks Wes, will keep an eye out a good bit of kit to have.
Horse

Post by **wesk** » Sat Mar 25, 2023 4:06 pm

What brand model dwell tach are you using?

Here's another helpful Publication from PS magazine: chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/http://willysmjeeps.com/downloads/24%20 ... esting.pdf

horse · Post by **horse** » Sat Mar 25, 2023 4:13 pm

I have not bought one yet as I did not know how to wire it.
Open to advice on that as well.
Horse

Post by **wesk** » Sun Mar 26, 2023 12:35 am

I have used a Military Simpson for many years and got used to it. I also have civvy Dwell/Tachs from Craftsman and Sun.

You can download and review test set handbooks here:
http://www.willysmjeeps.com/v2/modules. ... oad&cid=57

horse · Post by **horse** » Sun Mar 26, 2023 1:15 am

Thanks for the information.
I will check out the suggested units and see what is available over this side.
Horse.

horse · Post by **horse** » Sun Mar 26, 2023 5:30 am

Bit of a result.
One of my old timing lights has a switch to show RPM which I had forgotten about, so all is well again.
I will still look out for the military kit.
Horse.