Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/)
-   Porsche 911 Technical Forum (http://forums.pelicanparts.com/porsche-911-technical-forum/)
-   -   Engine swap and now Tach doesnt work?! (http://forums.pelicanparts.com/porsche-911-technical-forum/756328-engine-swap-now-tach-doesnt-work.html)

pyite20v 06-16-2013 01:28 PM

Engine swap and now Tach doesnt work?!
 
I have been reading threads for hours but cannot seem to find my exact issue.

I have a 72 that had an 83 SC 3.0 in it. I did an engine swap last weekend for a ROW 3.0 from 1980. Everything works great except for the tach, which doesnt work at all. Turn signal lights and high beams seem to work, and it worked fine before, so I am not sure which step I am missing.

I tried two CD boxes and both seem to work fine. I was told the new engine has an alternator with an external voltage regulator, but everything else is the same. I have checked for loose wires on the back of the tach but all seems to be fine.

Any ideas?

Anyone in the mill valley or SF area have a spare tach I can put in to make sure the tach hasnt gone bad? (although it worked fine last week).

http://forums.pelicanparts.com/uploa...1371418115.jpg

timmy2 06-16-2013 01:37 PM

Check tach pin out on the new versus old 14 pin connector. I believe it is pin 12 on the connector for the '80, may be different on the '83 to match the '72 chassis.

pyite20v 06-16-2013 01:44 PM

Okay timmy2, what am I looking for?

timmy2 06-16-2013 01:50 PM

Check the continuity from 6 pin CDI harness connector (middle black wire) on the new wiring harness goes to the same pin as the old one did on the 14 pin connector.
I'm out for Father's Day with my boy right now. I'll check back later.

pyite20v 06-16-2013 01:59 PM

Okay I took the covers off of each connector and I defintely see some differences.

Here is the old connector
http://forums.pelicanparts.com/uploa...1371419924.jpg

Here is the new connector
http://forums.pelicanparts.com/uploa...1371419944.jpg

Here is the pin box

http://forums.pelicanparts.com/uploa...1371419965.jpg

The wires are definitely in different spots for the old vs new harness. How can I tell what goes where?

Thanks!
Happy Fathers day!

pyite20v 06-16-2013 02:30 PM

Yes thanks for the lead timmy! I rearranged the wires so they mimicked the old wires and now my tach is back!

This is great because now I can really wind the new engine out and actually know where redline is!

timmy2 06-16-2013 02:52 PM

There ya go!
It's drive it like ya stole it time:)


All times are GMT -8. The time now is 08:30 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.