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Discussion Starter #1
I have an 88 with no tach. I have an old tach from my other truck, it has four wires, i need to kno where to hook these wires up to. pics from someone that has an aftermarket one hooked up would be great.
 

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Typically, the 4 wires would be:

12V switched power

Ground

Instrument Light circuit

(-) Terminal of coil


Since you didn't mention what the brand of tach is, I couldn't tell ya which wires are which. The old Sun tach I had in my old truck was:

Red-12V
Black-Ground
White-Instrument lites
Blue-Tach (I think it was blue anyway)
 

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84broncorig said:
I have an 88 with no tach. I have an old tach from my other truck, it has four wires, i need to kno where to hook these wires up to. pics from someone that has an aftermarket one hooked up would be great.
If you have a Bronco tac, you can either wire it directly OR if your dash had one previously mounted it will plug right in. If you dash didn't have one you can get the printed circuit and replace the one on the back of the instyrument panel. A picture of one attached.

I have one of those in my garage if you want it. The wiring harness in your truck should already have the wires necessary to run it. A printed circuit for an non tac truck doesn't have the part you see on the back of the TAC position.

There is no light connection on this tac. It has a switched 12V, a connection to the (-) side of the coil and, a connection to ground at the distributor, plus another ground at the ignition module.
 

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Here is the circuit diagrams for the TAC. As you can see you get the 12V from fuse 18.
 

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Discussion Starter #5
i can't tell ya what the brand of this tach is cuz i have no clue. it doesn't have it on there newhere. it came with a truck i bought from a farmer about 6 years ago. my truck didn't have a tach, but i was lookin at the wiring diagram in my book and it shows the wires. i just need to know exactly where to hook this up at under the hood. the ford it came from was a 300 carb, its goin on a 302 EFI. the wires are black, green, red and white. Black is obviously the ground, i am think white for light, red for switch, green to the ignition mod??
 

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OOPS should have been page 18
 

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84broncorig said:
i can't tell ya what the brand of this tach is cuz i have no clue. it doesn't have it on there newhere. it came with a truck i bought from a farmer about 6 years ago. my truck didn't have a tach, but i was lookin at the wiring diagram in my book and it shows the wires. i just need to know exactly where to hook this up at under the hood. the ford it came from was a 300 carb, its goin on a 302 EFI. the wires are black, green, red and white. Black is obviously the ground, i am think white for light, red for switch, green to the ignition mod??

If it has 4 studs on the back and will fit into the instrument panel it is the TAC that would normally be there. The connections are as shown on the diagrams.
 

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Discussion Starter #8
i was just lookin on my coil, i couldn't find the tach test
 

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84broncorig said:
i was just lookin on my coil, i couldn't find the tach test
It just goes on the (-) terminal.
 

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Discussion Starter #10
the plug comin from the bottom of the coil, there are two wires, where do they go, would one of them be the tach test??
 

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the TAC connects to pins 1, 11, 12, and 13 as follows: Pin 1 black with light green stripe, Pin 11 dark green with yellow stripe, pin 12 black with light green dash, and pin13 red with yellow stripe.
 

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84broncorig said:
the plug comin from the bottom of the coil, there are two wires, where do they go, would one of them be the tach test??
Yes, like I told you earlier, your harness should already have the wires all the way back to the connector at the instrument panel.
 

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Seabronc said:
If you have a Bronco tac, you can either wire it directly OR if your dash had one previously mounted it will plug right in. If you dash didn't have one you can get the printed circuit and replace the one on the back of the instyrument panel. A picture of one attached.

I have one of those in my garage if you want it. The wiring harness in your truck should already have the wires necessary to run it. A printed circuit for an non tac truck doesn't have the part you see on the back of the TAC position.

There is no light connection on this tac. It has a switched 12V, a connection to the (-) side of the coil and, a connection to ground at the distributor, plus another ground at the ignition module.
i put a used bronco tach in mine. come to find out i had to do a little cutting with a dremel to keep my original speedo/odo. sucked at the time but i like the results... :chili:
 

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Answer one question so I don't take you down the wrong path. Does it fit into your instrument panel as is? In other words, can you take out the blank section and insert the TAC thru some existing holes?

Here is the post arrangement as looking at it in the picture above:

Top left post goes to pin 11 dark green with yellow stripe on the plug connector.
top right post goes to pin 1 black with light green wire via the instrument voltage regulator.
botton left post goes to pin 12 black with light green dash
bottom right post goes to pin 13 red with yellow (switched 12V)
 

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Discussion Starter #15
no, there is no space for a tach on the inst. cluster. the speedo is right in the middle where the tach would be and it has the oil, gas, batt, and temp off to the sides.
 

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84broncorig said:
no, there is no space for a tach on the inst. cluster. the speedo is right in the middle where the tach would be and it has the oil, gas, batt, and temp off to the sides.
What year truck is this?
 

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Discussion Starter #17
88
 

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84broncorig said:
OK! You did say that right in the beginning didn't you. I ignored that and went by your user ID. OOPS, Ignore all I have said so far, I think. What year truck did the Tac come from?
 

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Discussion Starter #19
its a cheap aftermarket that was mounted in my 80 F150, its small but would do the trick.
 

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84broncorig said:
its a cheap aftermarket that was mounted in my 80 F150, its small but would do the trick.
OK sorry about all the Ford BS. Nothing I said about the TAC has any bearing on this.

Jimsbronc is most likely the answer for you

"Typically, the 4 wires would be:

12V switched power

Ground

Instrument Light circuit

(-) Terminal of coil


Since you didn't mention what the brand of tach is, I couldn't tell ya which wires are which. The old Sun tach I had in my old truck was:

Red-12V
Black-Ground
White-Instrument lites
Blue-Tach (I think it was blue anyway"

Sorry about that :banghead

:thumbup
 
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