1970 Mach 1 Hood tach
#11
Let us know if it works.
Reply
#12
These guys on the site have been amazing in trying to help!

Thanks for the great help.

Let us know how it all works out and what you figure out.

We all love someone else's mystery.
Reply
#13
(03-07-2018, 03:51 AM)Steven Harris Wrote: These guys on the site have been amazing in trying to help!

Thanks for the great help.

Let us know how it all works out and what you figure out.

We all love someone else's mystery.

Well, I have tried everything suggested but still the hood tach does not work. Running out of ideas other than somehow the hood tach is suddenly inoperative or broken.
Reply
#14
If you've tried everything, including a new Tach Adapter, you are probably correct that the tach is inop.

Did you ever determine if the tach is voltage or current triggered?  If you don't know, did you try wiring it to the Tach Adapter for both methods?  These hood mounted tachs were dealer installed options, so who knows if they were current or voltage triggered.  Do you know how was it connected to the original ignition system?  Knowing that, would answer the current or voltage triggered question.  I truly doubt MSD tech support knows.  Most of those people are too young to be familiar with these older cars.
Reply
#15
(03-07-2018, 08:10 AM)1969_Mach1 Wrote: If you've tried everything, including a new Tach Adapter, you are probably correct that the tach is inop.

Did you ever determine if the tach is voltage or current triggered?  If you don't know, did you try wiring it to the Tach Adapter for both methods?  These hood mounted tachs were dealer installed options, so who knows if they were current or voltage triggered.  Do you know how was it connected to the original ignition system?  Knowing that, would answer the current or voltage triggered question.  I truly doubt MSD tech support knows.  Most of those people are too young to be familiar with these older cars.
The tach was originally wired as such: green wire to negative coil side, red wire to positive coil side, black to ground, yellow to lights.
Reply
#16
Wow!  That doesn't sound correct for either a current or voltage triggered tach.  With the green wire to the negative side of the coil I'm guessing it was a voltage triggered tach.  And the red wire to the positive side of the coil was merely a convenient power source.  But that power source only has 12V during cranking.  During run, it would be less than 12V since the power to the original coil went through a resistor wire reducing voltage to the coil and points.

Did you connect it to the MSD Tach Adapter as a voltage triggered tach?
Reply


Possibly Related Threads…
Thread Author Replies Views Last Post
  smooth window operation on 70 Mach CUSTOMMISER 2 1,471 08-15-2022, 12:10 PM
Last Post: CUSTOMMISER
  Is your Mach 1 on Google Earth Street View? Rare Pony 2 1,878 03-05-2022, 07:30 AM
Last Post: Rare Pony
  72 Mach 1 Power Steering Pressure Hose Jelly 1 2,942 11-07-2021, 08:42 AM
Last Post: JTS71 Mach1
  Turn signal electrical issue 1970 Mach 1 flananuts 2 2,549 10-21-2021, 09:01 PM
Last Post: flananuts
  '03 Mach 1 fuel pump skidmarky 1 2,725 04-29-2021, 11:06 PM
Last Post: JTS71 Mach1
  69 Mach 1 rear seat install RostaRob 8 18,613 06-29-2019, 02:44 AM
Last Post: rindel
  trouble with the hood mounted turn signal goldmach1 13 22,851 09-27-2018, 08:12 AM
Last Post: goldmach1
  How much of your Mach 1 have you replaced? Mister 4x4 8 18,287 07-13-2018, 08:45 AM
Last Post: Steven Harris
  69 MACH 1 fuel cap? noroz 6 20,609 06-06-2015, 03:51 AM
Last Post: 1969_Mach1
  04 Mach 1 exhaust rattle Bogie#7 11 31,157 05-30-2015, 05:47 PM
Last Post: 1969_Mach1

Forum Jump:


Users browsing this thread: 1 Guest(s)
[-]
Latest Threads
What's One More Iron In The Fire!
Last Post: fram lee666
03-18-2024 06:21 PM
» Replies: 125
» Views: 238047
"Jacobra"
Last Post: JTS71 Mach1
06-30-2023 11:13 PM
» Replies: 86
» Views: 150737
My old Queensland Ambulance
Last Post: JTS71 Mach1
06-30-2023 11:08 PM
» Replies: 5
» Views: 1682
New member from San Jose, CA
Last Post: JTS71 Mach1
05-09-2023 08:39 AM
» Replies: 12
» Views: 3954
Saving Seatbelts
Last Post: Jim
02-19-2023 10:23 PM
» Replies: 2
» Views: 9109
Sourcing new wheels
Last Post: JTS71 Mach1
01-25-2023 02:34 PM
» Replies: 1
» Views: 1993
Shaker Air Filter
Last Post: JTS71 Mach1
01-08-2023 02:24 AM
» Replies: 3
» Views: 1465
1971 Mach 1 parting out interior parts -...
Last Post: ylwhrse
12-22-2022 01:38 PM
» Replies: 0
» Views: 640
Painting
Last Post: Rare Pony
12-14-2022 06:24 PM
» Replies: 2
» Views: 1964
WELCOME ALL NEW MEMBERS INTRODUCE YOURSE...
Last Post: JTS71 Mach1
08-31-2022 01:36 PM
» Replies: 82
» Views: 157017
1970 mach 1 matching numbers
Last Post: Kstweeter
08-31-2022 10:31 AM
» Replies: 1
» Views: 1086
Brake booster/servo hose length
Last Post: JTS71 Mach1
08-23-2022 09:40 AM
» Replies: 7
» Views: 2992
New Member
Last Post: JTS71 Mach1
08-20-2022 11:18 AM
» Replies: 2
» Views: 1498
smooth window operation on 70 Mach
Last Post: CUSTOMMISER
08-15-2022 12:10 PM
» Replies: 2
» Views: 1471
Blinkers on solid
Last Post: busted21
08-09-2022 03:58 AM
» Replies: 14
» Views: 8692
Blinkers on solid when lights on.
Last Post: JTS71 Mach1
08-08-2022 12:06 PM
» Replies: 1
» Views: 1719
351 cj running hot
Last Post: busted21
08-08-2022 12:13 AM
» Replies: 5
» Views: 3403
Major Winter projects
Last Post: JTS71 Mach1
07-09-2022 05:12 AM
» Replies: 49
» Views: 21140
Happy Fathers Day!!!
Last Post: JTS71 Mach1
06-20-2022 02:34 AM
» Replies: 0
» Views: 1681
1969 Raven Black 390 Looking For
Last Post: mason1958
06-11-2022 09:48 AM
» Replies: 10
» Views: 15079

>