I would like to install an after market tach on my 2000 F-150, 4.2L, 5 speed. I previously owned a similar '97, and after inquiring at my dealership, I was told it could not be installed. I still have the tach, and I've been thinking about it again. Does any know how to do this? thanks!

 

I would check with the manufacturer of the tach. Which brand is it anyway?

With a distributorless ignition like yours it can be tricky. Well, trickier than with older single coil systems.

I checked [link:http://www.autometer.com/hp/index.html|Auto Meter's site] and found this in the [link:www.autometer.com/hp/index.html|FAQ]. It is for '96-'98. I would guess it's possible to do it on a '00 truck. But, the wire may be in a different location and/or be a different color. Or maybe it's the same, and the FAQ hasn't been updated since '98.

[font color=green]Ford 4.2L and 4.6L F-SERIES Trucks ('96 - '98 only)
Tach output is obtained from the PCM (powertrain control module) which is 104 wire connector, and is typically located in the engine bay, on the passenger side firewall. Look for pin number 48, which is usually a white wire with a pink or red stripe.[/font]

 

thanks for the info. I was unable to find #48, mine only went up to 42. I did try the two wires that were white with red or pink stripes, no luck. The tach is a Sunpro mini-tach.

 

Be careful about hooking up your tach, if your not absolutely sure you have the right wire. You can damage your tach, or worse, your truck.

Go to the [link:www.actron.com/cgi-bin/web_store.cgi?page=suntach.htm&cart_id=3317260_158 68|Sunpro Products, Tachometer Page] to find your user's manual.

I looked, and it says check with your truck's service manual for DIS systems not shown. And guess what, your system is not shown.

I would stop by the Ford service dept. where you bought your truck and ask them which wire is correct. Ask nicely, and you will probably get an answer. Talk to the service manager, if you have to. If they still won't help you, go to your salesman. Tell him you're not likely to buy another truck from him, if his service dept. is going to treat you like that.

The service guys will see it as an inconvenience, with no reward for their time. Don't let them fool you, though. They can find the wire if they want to. Your salesman will see dollar signs on your forehead, and doesn't want you walking away pissed.

Even if you bought the truck used, from a private party, you should be able to get some help from the Ford dealer. Just be subtle and nice, when you mention the letter you will write to the dealerships owner/manager, if you don't get any help. Of course, use that as a last resort.

If after you have tried those options, you still aren't getting anywhere, post back. I will see if I can find someone to help. I have a '97 F-150 4.2L, and have thought about putting a tach on, too.

 

Try searching the archives for the discussion list. I remember getting a good explanation of this, down to what color wire and where to find it, from the guy with the best answers and the best manners, "JMC".

I have a VDO tach in my 97 F150 XL, but I paid a speedo shop to put it in. Cost me two hundred and some bucks.

 

I have a 97 F1504.6V8. I just bought a 2-5/8" mini tach from Autometer. I need help on locating the wire to hook one the green tach wire to. I have Autometers instructions. Has anyone done this or have any guidance for me? Do you have to remove the battery to get at the PCM?

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Ford 4.2L and 4.6L F-SERIES Trucks ('96 - '98 only)
Tach output is obtained from the PCM (powertrain control module) which is 104 wire connector, and is typically located in the engine bay, on the passenger side firewall. Look for pin number 48, which is usually a white wire with a pink or red stripe. This also holds true for most Super Duty and van applications, up through '98. If the motor is a Triton V-10, it will need to be calibrated specially for a 5 ppr to read the correct RPM.
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I haven't done this, personally. I did look my harness over, though. Because, I plan on putting a tach in it, someday (no cash at the moment).

The PCM is located in the cab, above where your right foot would be, if you were sitting in the passenger seat. The 104 pin connector (wiring harness) plugs into it, thru the firewall. I have a 4.2L, and could do it without removing the battery. But, it would be pretty tight, trying to get at the harness with the battery in the truck. So, I say just remove it. The connector looks like it is held to the PCM by one bolt (10mm, I think).

I am unsure if there are actually numbers on the connector. I haven't taken my connector off,yet. But, I only see one white/pink wire in my harness.

I would push a nail thru the grommet in the firewall (that seals around the 104 pin connector), to make a hole for your tach lead. Push the green tach lead thru. Then solder it to the white/pink wire from that 104 pin connector. Tape it, or shrink wrap it up. Bolt the wiring harness back onto the PCM and re-install the battery.

Finish the rest of your connections to the tach, and mount it.

Seems like a pretty simple operation. Good luck. Let me know how it works out

 

It works! The XL has no wire at #48, so I had to punch it out and insert a wire. this is the tach lead. wire in the rest and it's good to go. There is also an interesting message in there about the built in digital tach. It's part of the odometer. Push the trip button and turn the key to "run", keep holding it and eventually it will print "test", keep pushing as it goes through various tests and a tach will eventually appear. Start the truck and push the button again and you have an in-dash tach.

Here are the instructions for the tach:
"Connect the light wire to the light fuse in the fuse box. Connect the power wire for the gauge to the radio circuit so that it would be powered when the switch is on. Connect the ground wire to a bolt near the fuse box. Run the tach pickup wire through the firewall. I went out through the hood latch cable boot. Now the tricky part is connecting to the computer. I had to remove the battery to get to it. It should be located on the passenger side firewall(it will be a big plug with 104 wires coming out of it, or so). If you DON'T have an XL model you look for pin number 48, which should have a white wire with a pink or red stripe. (If you need to unplug it from the computer there is a bolt in the middle of the connector.)Just splice the tach wire into this wire at pin 48. For those of us that have the XL model there will not be a wire at the 48 location on the connector so what I did was disconnect from the computer. Removed the cover on the side of the connector that plugs into the computer and using a stiff wire punched through the rubber at the pin 48 location and installed a socket on the wire and then pushed the socket back up into the connector and reinstalled the cover. Plug back up to the computer(be very sure that you undertsand the numbering on the connector and that you are really on the pin 48 location)." Thanks to everyone for thier help.

 

Cool, but how did you know for sure you had #48? Is there a picture that comes with the tach? Are there numbers on the connector?

BTW, my '97 has a regular old trip odometer (not digital). :-(

 

The pins are numbered on the ends, just count forward or back. You will probably have to unbolt the 104 connector, just one bolt to see it all clearly.

 

What size pin connector did you use for the end of the green tach wire? Did you use special gizmos to tap into the fuse, and if so where did you get them

 

OK, I got my Autometer 2-5/8 mini tach mounted no problem. It looks awesome on the A-pillar. The wiring is another issue. I pulled out my battery and battery tray to get at the 104 connector. I was able to locate the pin 48 and the associated "WIRE" (white w/pink stripe). NOTE that my truck is an XL and it did have the "WIRE" in place, and no my truck does not have the factory tach. I tried to trace the wire to another place on the truck which would be an easier place to solder. I gave up and just soldered it right by the 104 connector. I just took an exacto knife and carefully shaved about a 1/4" inch of insulation off the "WIRE" mid wire (I was able to get about a 1" loop away from the main wire loom) and then soldered it and put on some RTV silcone on the joint. I have tested the tach with long wires direct to the battery and the tach works fine!

My big issue is connecting the tach hot lead to something that is only hot while the ignition is on, and tach light wire to something that is only hot while the lights are on? I have the mini fuses in the cab (which meet the above criteria), but I can't find any gizmos that will allow me to jump the required wires on a fuse. The fuses under the hood are maxi fuses and in addition to not being able to find gixmos for them, they appear to all be hot when the ignition is off (can't use them). It appears the gizmos are made for fuses which are a size right between the mini and maxi fuses. How were you able to do this and/or where did you find the gizmos????

Riding with a show tach....
1997 F150 XL
4.6 V8