Additional Tach Under The Hood Ok Or Harmful ?

[SCOTTY]

Greetings !
My Ranger has the factory tach but for awhile I've been thinking about installing a tach under the hood. What I'd like to know is if it could potentially harm the eec or tfi module or anything else for that matter. Just want to play it safe guys. Thanks !

 

[SenorNoob]

I'd be concerned with the longevity of any tach left under the hood all the time... Outside that, how much draw does a tach have on whatever circuit generates the signal? Pretty sure people have used and aftermarket tach along with the factory before. So maybe not a problem?

 

[SCOTTY]

I'd be concerned with the longevity of any tach left under the hood all the time... Outside that, how much draw does a tach have on whatever circuit generates the signal? Pretty sure people have used and aftermarket tach along with the factory before. So maybe not a problem?

Not worried about longevity if your referring to it being under the hood w/the elements.
I have a cheapo in mind & I can use some silicone where the harness enters the back of the tach @ least.
& that's what I'm wondering if you mean current draw & if anything else could be effected.
The signal would be feeding 2 tachs.
This is what I'm looking @：
2" 52mm 12V Car Tachometer Gauge Meter 0-8000 RPM w. LED Shift Light Universal | eBay

 

[SenorNoob]

I say go for it. Just make it easy to disconnect if there are problems.

 

[SCOTTY]

I say go for it. Just make it easy to disconnect if there are problems.

Pretty close to pullin the trigger on it but still somewhat concerned. I'd hate for it to put a strain on the TFI or whatever else that could be affected.
Thanks for your input SN !

 

[Snoranger]

There would be no reason to have a tach under the hood 99% of the time. The only thing it would do is add another point of failure that could take out a TFI module and leave you stranded. I would wire it up with a weatherpack connector and make a blank dummy plug. I would remove the dummy plug and only plug in the tach when needed… but I like to make it home.

 

[85_Ranger4x4]

Dunno if they are available elsewhere (I assume something similar should be) but this is what I use for checking engine RPM when I am under the hood. Connects pretty easily when needed and works well enough for dialing in timing and setting the carb.

Amazon.com: Actron CP7605 Dwell/Tachometer/Voltmeter Analyzer : Automotive

 

[SenorNoob]

I like it. Keepin' it old school right down to the tools.

 

[scotts90ranger]

You could just put a switch on the signal wire leading to the underhood tach and only turn it on when you wanted to look at it, that would be pretty safe... the tach signal is like a 5-50V square wave so a higher voltage rated switch would be fine...

 

[Uncle Gump]

My timing light has a digital tach... simple.

 

[scotts90ranger]

I think I own a timing (don't ask me where it is... and it isn't digital) light but the only vehicle that I have that needs one is my boat...

But yeah, at work we have those and that is a definite reasonable option, would be a good way to set the base idle screw...

 

[SCOTTY]

Lots o' good input guys ! Thank you !
Overnite I thought of putting a switch on the signal wire like scotts90ranger suggested.
I'll get the tach in the link I posted & use a mini toggle switch I picked out. The body looks deep enough on
the tach & thread depth seems pretty good on the switch so if I can get inside the tach maybe I can drill two 1/4" holes, 1 on the back of the tach body & 1 on the black housing to mount the switch. Just depends if the body butts up to the housing in the back & how thick the plastic is. We shall see ! If not I'll come up w/something.
I can seal things up w/some silicone. (I'll make sure it works 1st !)
Thinking of mounting the tach somewhere on the left side but not to close to the coil.
The way I see it, another neat useful toy !