65 barracuda factory tachometer wiring ?

-
stroker402

stroker402

1968 dart GTS convertible
Joined
Jan 30, 2006
Messages
1,096
Reaction score
473
Location
milwaukee wi.
I have a 65 formula S with factory tachometer . when I start the car the tach needle pins all the way to right. when I shut the engine off the needle will fall back to "0" again . I do not see any wire that is suppose to attach to neg side of coil . was told it is suppose to be a grey wire . the sender unit is above the kick panel where it should be with all the wires (4) attached to it.
Can anyone tell me or snap a pic of which terminal block it goes into . upper or lower etc. my 65 formula s tach but has no wire going to the coil.
Question :
Is that coil wire in the wire harness ? or is the wire separate coming directly from the bulk head block to the coil ?
here are 3 pics I found of the 65 barracuda tach and wires.
I can't see where the wires go even by enlarging them . my eyes are bad maybe you guys can make it out. I see two wires that have masking tape on them too , maybe where they go ..
Thanks guys for any info !
john

formulastach 001.jpg


formulastach 002.jpg


formulastach 003.jpg
 
Last edited:
I'm going to throw my "2 cents" in here. I'm not real familiar with this type of tachometer, but if you can figure out where it gets its ground, you will find that is where your problem is. These type of instruments, must have a GOOD ground. Like I said, just my 2 cents.
Let us know what you find out.
Norm
 
I also wanted a console tach for my 64 Sport Fury, but I read that many people had trouble with those old sending units. So I bought the correct tach off eBay and it didn't even include a sending unit. I read that the gauge rebuilders can just put everything into the tach, so I had Redline Gauge do it. That way I would get the tach calibrated with greatly simplified wiring (as shown). With their nice labeling, even I can figure it out. Also, when these tachs are rebuilt, they can handle more modern ignition systems.

I know this does not answer your question, as your sending unit may work just fine. I do know that on the 67 Barracuda I have, a grey wire does go to negative side of the coil. On the 67, there is no sending unit. I tried looking for your wiring diagram online, but I couldn't find it. Good luck.
IMG_1380.JPG
 
g413 said:
I also wanted a console tach for my 64 Sport Fury, but I read that many people had trouble with those old sending units. So I bought the correct tach off eBay and it didn't even include a sending unit. I read that the gauge rebuilders can just put everything into the tach, so I had Redline Gauge do it. That way I would get the tach calibrated with greatly simplified wiring (as shown). With their nice labeling, even I can figure it out. Also, when these tachs are rebuilt, they can handle more modern ignition systems.

I know this does not answer your question, as your sending unit may work just fine. I do know that on the 67 Barracuda I have, a grey wire does go to negative side of the coil. On the 67, there is no sending unit. I tried looking for your wiring diagram online, but I couldn't find it. Good luck.
View attachment 1715015533
Click to expand...
Thanks G413 for additional info.
I just need to find that wire that come thru the bulk head on the firewall that attaches to the coil.
 
Would anyone out there have a Service manual for the 65 barracuda that could trace that wire down and see it's routing thru the harness. I haven't see anything in particular for the formula S car tach wire illustrations yet .
Thanks guys !
 
stroker402 said:
Would anyone out there have a Service manual for the 65 barracuda that could trace that wire down and see it's routing thru the harness. I haven't see anything in particular for the formula S car tach wire illustrations yet .
Thanks guys !
Click to expand...
As far as I know, the wiring for tachometer ( being optional equipment ) never was included to the cars wiring harness, or those service manual schematics. The tach package included a diagram, the wire, a fuse clip that went in a accessory slot of fuse box, and the grommet for where a wire passed through the firewall.
 
65 and 66 wiring sheets from manual attached.

66 shows incomplete Tach wiring and 65 has none. I included the Fury tach drawings in both at the end that may help shed some light.
 

Attachments

  • 65 Valiant wiring.pdf
    438 KB · Views: 336
  • 66 Barracuda wiring.pdf
    449.9 KB · Views: 313
thanks for the replies guys !
Well I have wire diagrams now . but the hundred Dollar question is , if this tach and sender wires are enclosed in a harness ( which they are) which position of the firewall block plug end is the one where the neg lead to the distributor is .
I guess what I really need is for someone that has the 65 factory tach to look and see where his neg wire from the coil leads to. does the coil wire go directly into the interior of car to the tach or does the coil wire go into the harness . if it goes into the harness it has to come out a some point and plug into the block on firewall. That is the info I am seraching for. Thanks guys !
john
 
Look at the 65 drawings, Bulkhead Terminals G and 2 appear to be the only unused on the bulkhead. probe from the D terminal on the Tach sender to either of these bulkhead slots. If it is not there then it must pass through a location other than the bulkhead connectors.
67-69 the Gray Tach wire to negative coil was routed through a separate firewall hole all by itself.
 
Thanks Gerald !:thumbsup:
That is the info I was hoping for. I'll do some more probing this weekend when it warms up here.
john
 
Does anyone have a clear photo of the inside of the sender circuit board ? found out that I have one burned out resistor that I can't find the colors on it because it has turned black . it's on the 12 volt line for that resistor. the white arrow shows where the resistor was . I removed it.

IMG_6124.JPG
 
I had another old sun tach from 1964 laying around , we tried to use its circuit board and run my dash tach with the old sun tachs circuit board together . the result >>> it just pinned the dash tach needle ... going to call theses tach places to ask if they know the size of that resistor that burned out in my sender unit.
 
stroker402 said:
I had another old sun tach from 1964 laying around , we tried to use its circuit board and run my dash tach with the old sun tachs circuit board together . the result >>> it just pinned the dash tach needle ... going to call theses tach places to ask if they know the size of that resistor that burned out in my sender unit.
Click to expand...

They likely do know the value If you plan on running points!

The issue is if you are running stock points or not.

If you have upgraded the ignition like most of us, and you should short of a 100 point restoration!

The factory board will not function correctly. This is why I posted a few examples of aftermarket boards. If you have points or Chrysler upgrade electronic you may want "A". If you use MSD you may want "B". Do your research based on the ignition system you are using or plan to use and get the board that is designed to work with it!
 
By the way the piece that ressembles a transformer on your original looks like toast as well!
 
I use a Pertonix III in the factory distributor with matched coil and ballast that is hidden jumped with 12AWG solid so no harness mods!

I have the RTE board with calibration in my 69 version factory tach and it seems to work and react pretty good!
 
stroker402 said:
Thanks Gerald !:thumbsup:
That is the info I was hoping for. I'll do some more probing this weekend when it warms up here.
john
Click to expand...

Did you ever determine where the coil feed wire passed through the bulkhead? Some other folks here might like to know!
 
1969383S said:
By the way the piece that ressembles a transformer on your original looks like toast as well!
Click to expand...

Yeah Gerald .. one of those coils got so hot it melted the wax coatings , and one other resistor looks bad also. so it is pretty much TOAST ! Persons before me tried to get it to operate and hooked a hot wire where they should not have been hooked. Melt down .
 
1969383S said:
Did you ever determine where the coil feed wire passed through the bulkhead? Some other folks here might like to know!
Click to expand...
Gerald .. The tach wire to (-) coli passed thru the "G" Terminal on firewall bulk head. In the schematics , that's the one that did not have a wire coming out of it. Maybe if mopar made a supplement service repair manual for 65 , it might have showed the tach schematics .
 
Last edited:
You must log in or register to reply here.
-

Back
Top