Author Topic: 1973 8k tach and 160 mph speedo  (Read 523 times)

Bottom Feeder

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1973 8k tach and 160 mph speedo
« on: April 19, 2025, 07:23:20 AM »
Greetings.  I just picked up a set of 1973 Trans Am gauges: 8k tach, 160 speedo and earlier fuel and voltage gauges. I read that if the tach needle "swings" with movement that's a good sign. The speedo works; I tested it.  Here's my question.  Can I use a multi-tester to create a simulated current to test the tach, fuel, and voltage gauges? I'm pretty sure the voltage gauge would be easy. Thanks 
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b_hill_86

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Re: 1973 8k tach and 160 mph speedo
« Reply #1 on: April 19, 2025, 05:38:58 PM »
Not knowing what kind of tool you have I’ll just say, the tach runs off 12v and a pulsed signal from the distributor and the fuel, oil and water read a given value based on a certain level of resistance. You could test for functionality by applying 12v to the given gauges (not tach) which should cause them to peg if I remember right. To test for accuracy though you’d need to know and simulate those values which are listed in the service manuals. When I tested a tach I used my car to provide the signal.
-Brian-

1977 Trans Am 400 4 speed

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Re: 1973 8k tach and 160 mph speedo
« Reply #2 on: April 20, 2025, 08:47:44 AM »
Thanks Brian!!
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b_hill_86

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Re: 1973 8k tach and 160 mph speedo
« Reply #3 on: April 20, 2025, 04:51:19 PM »
Hope it helps !
-Brian-

1977 Trans Am 400 4 speed

Re: 1973 8k tach and 160 mph speedo
« Reply #3 on: April 20, 2025, 04:51:19 PM »
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