I've been planning on putting a new gauge in for weeks now and finally took the first steps yesterday. Went to O'Reilly's and told them I wanted an electric gauge with the sender, he grabbed an electric one and then was having trouble explaining how it hooks up. That one had the gauge and the sender but no wire in between, you had to get your own. The sender side just had a little clip where you attach a wire I suppose, he didn't really know either so he came back with another gauge w/ sender, not realizing it's a manual gauge.

I could install this manual gauge but it requires a 7/8" hole be drilled in the firewall, I don't have a drill bit that large or think that my drill could even handle it.

So I can either keep this one and find a drill and bit, exchange it for the electric gauge that he apparently has no idea how to install and neither do I (it had a couple wires coming off the gauge but that's it), or look for something else.

Already drained some of my coolant and got the sensor loose so I really want to get this done ASAP. Thanks,

Zac

 

sharp hole saw cuts the firewall like butter. that is what i used to drill the hole for my firewall boot that i showed in your other thread.

 

I'd go with electric. I wouldn't want any mechanical gauges inside my cab for the simple reason that if the hose burst, I get hot oil or coolant pissing everywhere in the cab.


Electric gauges are just as reliable as mechanical ones anyways.



One wire goes to the sender unit that screws into the block. The other is for power for the light in the gauge.

 

I actually have one of those somewhere but I'm almost positive it's larger than 7/8", more like 2" I'm thinking. Would one of those even work on a little $20 corded Black and Decker drill? That's all I've got right now.

Thinking I might just go exchange this for an electric. As far as the gauge having short wires coming off, and the sensors having no wires (hook it up yourself apparently), does this sound right?

 

Thanks John, you just answered my question. Basically I just need to attach a longer wire to the extension wire coming off the gauge, hook that one up to the sensor that comes with it, and then hook the other side up to switched 12v power?

 

Not to sound like an ***, but did either you our the guy at the O'Reilly's look at the install directions for the electric gauge? It would have explained to run a single wire from the sender back to the gauge. On the back of the gauge should be a place for the sender to hook up, and likely a 12V+ and GND. The lighting for the gauge most likely would be a separate 12V+ and GND (unless it is an LED the connections shouldn't matter).

An electric is easier to deal with if you have to remove the engine, or a component nearby. It only takes a second to pop off the wire and move it out of the way (useful on either the engine side or gauge side actually). Which is a major reason why I prefer the electric gauges. And any electric worth anything should be as accurate as a mechanical one. One advantage to mechanical gauges is that they will still read when the engine is off.

 

Yep, you got it!

 

tecgod, both my electric gauges on both my 6.9's always read when the engine is off as well.

 

John, I meant when the ignition is off.... oops!

 

if his mechanical gauge is anything like mine, it does not run fluid into the cab.

 

Even that. Ignition on or off. My electric gauges always read what ever is the temp of the coolant.


I sure like that for in my van with manual glow plugs, just need to glance at my temp gauge, and know if I have to hit the glow plugs or not.

 

tecgod, I would have looked at the directions but I had gotten a ride to the shop from my girlfriend and didn't have a lot of time. Also it really seems like the younger guys that work here really try to rush things, don't take a lot of time to talk to you about anything. Could just be my experience.

Either way, I'm taking this thing back in a few minutes and getting an electric gauge to put in. If anything else comes up I'll be asking on here about it, LOL.

 

Ok so I got the electric gauge, it's got the two wires for the lights, and then three spots where you're supposed to hook up the sensor, ground, and 12v switched power.

Can I just hook up the ground and 12v somewhere in the cab? Also what about the power for the light? I'm just wondering what all needs to go through the firewall, if I can get all those inside the cab then that'd just leave one wire that needs to be run through.

I looked and there doesn't appear to be anywhere I can run a wire through on the firewall without making another hole. There is one boot with a group of wires going through but I'm not sure if another would fit and don't want to mess up the ones that are there.

Also all I have on hand is 14 gauge wire, sounds like I'll need to pick up some more. What gauge would be recommended for hooking all of these connections up?

 

14 gauge wire is fine. Probably overkill, but it doesn't matter and will work just fine.

If you can't find a spot to stick the wire through, just drill a new one where ever you want, just make sure you don't drill into something on the other side. Make sure to use a grommet, or some tape around the wire to protect where its passing through the firewall.

Tap into any circuit that is hot when the ignition is on for the 12V+ to the gauge. The ground can connect to any metal piece under the dash, there should be a spot near the fuse panel where other grounds are connected.

For the light, it can share the ground to the gauge (splice near the gauge to save some wiring. You have two options for the light. If you want it to be on whenever the ignition is on, tie into the same wire for the 12V to the gauge. Generally people tie the light into the headlight/parking light circuit, so the gauge only lights up when the rest of the dash does. You can probably splice into that circuit near the headlight switch. Use a multimeter to probe around and find the correct wire.

 

That doesn't seem right. Yes its convenient, but in doing so is always drawing current, so is slowly drawing the battery down 24-7....

You may want to rethink how those are wired. When you turn the ignition on, they should read almost instantly anyways.