Installing a tachometer
Senior User
Joined: Dec 2004
Posts: 233
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From: centeral Ohio
The red line is max rpm's most engines shouldn't red line because, your engines power band drops off before it hits your red line. Like i said though i don't rev mine to 4'500. Although if your saying you can't you are sorely mistaken or my slow *** truck actually has a hundred or 2 hundred extra ponies that someone forgot to tell me got left out of the barn. After my about 16 sec 0-60 i'm fairly positive that it doesn't lol.
Logistics Pro
Joined: Aug 2003
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He he, I hear that. Mine is pretty good, but it's no 351w, and it sure won't rev like an import. I installed my tach on the A pillar just above the dash. As far as wires, I got lights from right at the switch, and switched power from the ignition. I grounded it to a factory harness ground under the dash, and the only one I had to run out was the tach wire from the coil. I will only use autometer now, because I once had a cheap one, and when I got an aftermarket ignition, it just bounced and jiggled.I called Jacobs and they said it had to do with the way the tach was made, but even the cheapest autometer was compatable.
Posting Guru
Joined: Jul 2003
Posts: 2,454
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From: Adams TN
My truck pulls hard.Better than a v8. I pulled a 7000lb LS160 NH skid steer at 65mph up hills down hills plenty of power left. (65 is top speed empty) on the 3 mi. of interstate than the 10 mi of back roads a 50mph. it did pull down to 45 on one hill by my house. It just pulls hard. as far as i know it has 3.55 ls that's what the tag says. It used to pull hay bales on a g/n. pretty good.
I never rev mine past 3k the only time it ever sees 3k is on the highway @65mph.
I usually shift before 2k
I never rev mine past 3k the only time it ever sees 3k is on the highway @65mph.
I usually shift before 2k
Thread Starter
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Junior User
Joined: May 2005
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ive been driving around all last night and today with the new tach and i can tell right away that ive never really gone above 3000rpm. It just sounds like the poor engine wants to kill itself whenever i get close to 3500rpm. I have a mr2 turbo track car that revs to 8000rpm in a heart beat and its a night and day difference between the 2 engines.
Senior User
Joined: Jun 2004
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Tach on a '78 Custom 300-inline
I installed my 2 1/16" diameter, 5,000 rpm Autometer tachometer in the left side of my dash, where there is a vent in those trucks with AC (Mine is a 1978 Custom non-AC). I usually shift 2000-2500 rpm, and rarely go beyond 3000 rpm. Truck has the stock, original 117K miles 300 engine. See my gallery to check the tachometer (great addition). I am also installing a set of triple 1.5" dia electric gauges in the next few weeks; it will be on the A-pillar (up, at eye level, close to the roof). I'll show pics when I am done.
Raul
Raul
Last edited by superbepro; May 19, 2005 at 06:12 PM.
Post Fiend
Joined: Jan 2000
Posts: 5,860
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From: Metro Detroit (Redford)
Originally Posted by javi2001
I had installed a Datcon one, 0 - 4000 RPM more accurated than 0 - 6000 for slow engines like 300's
I tapped the signal off one of the coil primary wires (which one is the question). When I discovered weird tach readings (would vary a couple hundred rpm with the dashboard dimmer, I called Datcon and told them, they said "radio frequency interference." I had grounded the tach to teh dash and when I followed their instructions and ran the ground directly to the battery negative terminal, the weirdness was gone.
Posting Guru
Joined: Apr 2003
Posts: 1,153
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From: Venezuela
I like use the signal comming from the Distributor stator, the purple wire on carby engines, BUT the Datcon ones can be connected to PIP signal coming from TFI-IV module to ECM computer or Even to the Spout connector
Junior User
Joined: Apr 2012
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This is a old threat I see, but I have a question of my own about the tach :)
I have a 85 Inline 6. It originally did not have a tach, but I bought a gauge cluster out of a 80s F-350 that had one. Anyhow, because my truck never had a hook up for a tach would I be able to install one? And if so how would I go about doing this?
I included some pictures of my new dash.
Thanks!
I included some pictures of my new dash.
Thanks!
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Moderator
Joined: Dec 2007
Posts: 7,987
Likes: 104
From: Boise, Idaho
If you swap in the whole gauge cluster it should work just fine. If you want, you can reuse all your old gauges, but the printed circuit board on the back of the cluster is what's needed to get the tachometer working. After that, it should pop right to life.
Moderator
Joined: Dec 2007
Posts: 7,987
Likes: 104
From: Boise, Idaho
What's your question?
As said, a gauge cluster with a tachometer is all that's needed to get one working. The printed circuit board on the back gets all the necessary signals that are already wired into every truck.
As said, a gauge cluster with a tachometer is all that's needed to get one working. The printed circuit board on the back gets all the necessary signals that are already wired into every truck.
Moderator
Joined: Dec 2007
Posts: 7,987
Likes: 104
From: Boise, Idaho
A couple ideas.
First, is that the tachometer simply doesn't work / is broken. This happened to me when I got one for my '84. I put it in and it just sat there. Every once in a while, it would come to life for a few minutes, and then die again. I left the gauge cluster in, but swapped in a different tach, and it worked great.
Second. Looking at the tachometer in the picture, I've only seen that tachometer in diesel trucks. I'm guessing the F-350 you got it from was diesel? If so, they may have a completely different wiring and ignition than a gas engine. (I don't know much about diesels.)
Maybe I need to renege on my previous comment and say that all you need is a gauge cluster with a tachometer from a gas truck?
Third could be that your wiring is screwed up, but I don't think that'd be the case, since it's the basic signals that your truck needs to run, such as the coil, ICM, etc.
First, is that the tachometer simply doesn't work / is broken. This happened to me when I got one for my '84. I put it in and it just sat there. Every once in a while, it would come to life for a few minutes, and then die again. I left the gauge cluster in, but swapped in a different tach, and it worked great.
Second. Looking at the tachometer in the picture, I've only seen that tachometer in diesel trucks. I'm guessing the F-350 you got it from was diesel? If so, they may have a completely different wiring and ignition than a gas engine. (I don't know much about diesels.)
Maybe I need to renege on my previous comment and say that all you need is a gauge cluster with a tachometer from a gas truck?
Third could be that your wiring is screwed up, but I don't think that'd be the case, since it's the basic signals that your truck needs to run, such as the coil, ICM, etc.
Moderator
Joined: Dec 2007
Posts: 7,987
Likes: 104
From: Boise, Idaho
It's interesting it came up because the first time I saw that tachometer was Saturday when I was out in the junk yard. I almost grabbed it but wasn't sure if the diesel/gas signals were compatible. Kinda wish I had just to see if it'd work. Plus, a 4500 RPM gauge would be cool for a 300.