 914 Tachometer not working |
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| vin man |
 Feb 7 2017, 03:20 PM
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#1
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Member  Group: Members Posts: 178 Joined: 19-February 10 From: Gilbert, Arizona USA Member No.: 11,380 Region Association: Southwest Region  |
I've done some searching and have not yet found a thread that I'm sure has been covered at some point.
The tach in my 72 does not work. The car was converted from fuel injection to carbs long ago. I believe the reason the tach does not work is because it is no longer getting a signal from the computer (no longer have an ECU in the car). How does one use the factory tach when I no longer have FI? In other car projects, I just ran a line from negative side of the coil to the back of the tach. But I don't think that will work here, will it? |
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| vin man |
Feb 7 2017, 07:06 PM
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#2
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Member Group: Members Posts: 178 Joined: 19-February 10 From: Gilbert, Arizona USA Member No.: 11,380 Region Association: Southwest Region |
According the repair manual I have, the wire from the back of the tach (black with purple) goes to a "ballast resistor". I've read in other threads that in later models, the resistor is internal to the tach. Or maybe the ballast resistor only used on the 914 /6.
Anyways, when I tracked the black/purple wire back, it went to the relay board in the engine compartment. There was not a black with purple wire coming off the negative side of the coil, but instead a green with red. I disconnected the green with red and spliced a wire right into the black with purple wire. Tach is now working! Thanks everyone. |
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Posts in this topic
vin man 914 Tachometer not working Feb 7 2017, 03:20 PM
timothy_nd28 There is already a black with purple stripe wire t... Feb 7 2017, 04:19 PM The Cabinetmaker The djet cars have a large black power wire, a sma... Feb 7 2017, 04:28 PM vin man Thanks. On my way over to test as you suggest. Feb 7 2017, 04:28 PM The Cabinetmaker Green with red is the oil pressure sender. Feb 7 2017, 07:52 PM vin man That's right. Maybe the wire for the tech was ... Feb 7 2017, 08:02 PM timothy_nd28 I'm just curious, where was the black and purp... Feb 7 2017, 08:39 PM rdauenhauer Tim is there a way to simulate the signals to ... Feb 7 2017, 10:02 PM vin man The black with purple stripe wire came to this plu... Feb 7 2017, 10:09 PM timothy_nd28 20 bucks in Radio Shack parts and a Iphone (or sim... Feb 7 2017, 10:18 PM timothy_nd28 The black/purple stripe wire should enter on the 1... Feb 7 2017, 10:24 PM
vin man
The black/purple stripe wire should enter on the ... Feb 8 2017, 09:32 AM timothy_nd28 12 pin connector is not the one by the firewall Feb 8 2017, 10:01 AM vin man
12 pin connector is not the one by the firewall
... Feb 8 2017, 10:15 AM vin man
12 pin connector is not the one by the firewall
... Feb 8 2017, 10:18 AM |
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