Installing Aftermarket Gauges — Tachometer, Engine Temp, Tranny Temp, Oil Pressure

[wayoffline]

My 87 5sp 4x4 cargo did not come with a factory tach which seems a bit lame for a manual transmission. I really didn't want a big huge thing that sat on top of the dash or bolted to the drivers side pillar. I found a 2 -1/16" one at harbor freight for $20.

I decided to mount it where the digital clock on LE models lives and where a useless rattling garbage collector resides on lower trim models. I know it is not in the ideal line of sight spot, but this is not a race car and I am sure I will only be using it as an occasional reference.

I removed the stock pocket and used the face of it as a template on the side of a unsalvageable center console in the same color as my interior. I cut the piece out with a combination of hack saw and dremel tool. Cleaned it up and rounded the edges with a file. Scribed the 2-1/16" hole with a compass and cut it out with the dremel. Once I had the gauge secured to to the new piece, I drilled a small hole in each corner, mocked it up in the van and drilled through the holes into the metal framework in the dash. 4 small metal screws installed (I think I will hunt for some black ones) and it doesn't look too bad!

The wiring was simple once I found out that toyota provided a test port for a tachometer on the side of the distributor. How cool is that? I read somewhere that all vans have a black wire that comes through the floor under the dash and is there for a tach (whether the van came with one or not), but I did not feel like hunting for it and wasn't sure if it was "plug and play" or not. I chose to run a wire under the carpet to the shift console. From the shift console I ran it through one of the shift linkage grommets, which puts it inches away from the distributor. A quick connect will make it easy to unplug when the passenger cover needs to come out. For the connection to the distributor I just drilled a hole the size of my wire in the top of the factory dust cap and ran the wire directly into the plug. A dab of silicone around the the hole in the cap to keep out dirt and moisture.

The rest of the wiring came off of the factory stereo wiring harness except for the backlight, which I spliced off of the backlight for the cigarette lighter (green wire in the 5th image). From the stereo harness I used the yellow wire for the direct positive, red for the ignition "on" power, and black for ground. The tach came with something like 6 different backlight colors- changeable by a button on the front.

I did learn one important thing once it was all installed and I went for a night time drive: there is a very good reason why your dash lights reside under a visor on all vehicles- the glare on the windshield is quite distracting. I will post again when I figure out how to shield the light without blocking the gauge's visibility!

[timsrv]

Very Cool! Looks like a green pac-man gobbling up a little white monster . I also used this spot to put some extra gauges. Here's a couple pics of mine:







For my transmission temperature gauge I got a plastic gauge holder at a local auto parts store and used double back foam mounting tape to put it on my dash. I like this location.......I should have put my coolant temp gauge here and put the trans temp gauge over by the clock.

[wayoffline]

I am humbled by the coolness of your setup Tim! Your gauges look like they have a bit of a shield around them- do you have any issue with backlight glare on your windshield? Is the housing for your trans temp gauge a separate unit, or part of the gauge? I think I would ultimately like to put the tack where you have the trans temp and put an oil pressure gauge where I put the tach. My oil pressure light comes on frequently even though the actual pressure checks out fine. I would be more comfortable being able to monitor the situation.

One other thing I have noticed is that the dimmer switch seems to have no affect on the tach, even though I used the power for the cig lighter backlight which will change with the dimmer switch. Anyone have any thoughts?

[timsrv]

The single gauge holder is just a plastic housing for a 2 1/16" gauge. It's open on the back so if you're standing in front of the van you can see the ugly part of the gauge through the windshield. Looks good inside though and it's functional. I never really noticed any glare/reflection issues, but can't say for sure about that as I've never really looked for it.

Thanks for the kudos on my gauges. I had a nice write-up with pics that I put on TVP when I installed these things. I went there tonight to get a link for you, but discovered my posts were edited and pics removed (probably by admin due to my TVT stamps). Oh well, their loss. I guess the more they do that the more visitors we'll get over here . Tim

PS: Due to your choice of location (clock location) your tach isn't as far out from view as my gauges are. I think your location is fine...........and you did a nice job! If I want to know what temp my engine is running I almost need a copilot .

[timsrv]

I recently added a tach to mine too. I put mine on top of the steering column. Here's a picture:



The blue LED light on my dash is tied into my oil pressure switch & a temperature switch I installed on my engine. A piezo buzzer is activated & that blue light will come on if my engine coolant exceeds 220 deg F or if I lose oil pressure . Tim

[technocj]

Thanks, what size is the coolant sensor fitting?

[amcneill]

hey everybody!

so im sure this has been covered somewhere, but searching hasnt found me anything so i figured id start a new thread...

id like to put an aftermarket temp sensor in my van, because ive heard of horror stories about stock gauges being horribly inaccurate. i was going to buy one of the cheap 20-30 dollar digital gauges from amazon and hook it up to the stock sensor, but im wondering if anybody would recommend buying a whole aftermarket sensor and putting it somewhere in the coolant path? is it just the gauges that are unreliable on our vans or is it the sensor as well?

thanks!

[originalkwyjibo]

I don't know that the gauges are inherently unreliable as much as non-specific as to the temperature. Gauges work within a certain range of resistance. In order to use the stock sending unit you would need to know it's operating range and then find a gauge that operates within that specific range. Most aftermarket gauges will come with a sending unit. You could run both an AM gauge and the stock gauge for comparison by utilizing the extra sensor port detailed in post #13 of this thread.

[amcneill]

thank you so much!!!

[Roger]

I recently installed an Engine Guardian gauge/sensor in my van. It came with a traditional coolant temp sensor, and two sensor leads that bolt to the block. I just used one of the bolt-on sensors attached to the coolant inlet, and the setup seems to work great. Gives me a very accurate view of engine temperature, and once I figured out what the average running temp range was, I set alarms to warn me if it goes above that range. It also has a purchase option that comes with relays, for activating fans at set temperatures. Really easy to install. Might cost a bit more than the other options you were looking at though.

http://www.carsensors.com/Engine_Guardian.html

[amcneill]

wow that is a bit more pricey than i was looking at.....when you say its bolt on does that mean it senses the temperature of the outside of the block, or is it a probe that goes into the coolant?

[bushcat]

Just want to post a thank you and share my picture of my tachometer. This tachometer was installed by a previous owner before I bought the van. I thought it would be difficult to get this working but then I found this post. I've had the van for about three years and never had the gauge working. It was hard to get a good connection because the spot were the plug is really hard to access and there's not enough wire to pull it out of the engine bay. It took me about an hour. I ended up jamming a two prong plug into it and superglued it in there. It's working! Pretty stoked to have a tach. Edit: I can't get the photo to show correctly.

[Benjie]

My oil light was intermittently coming on so I installed a oil pressure gauge. my oil pressure is around 60 while driving and goes down to 12 when warm and idling. Just wondering what pressure other people have on their vans especially at idle It's a 4ye. thinking about going with a little thicker oil I think my main bearings might be a little tired. Right now I'm running 10w30 thanks for any input.

[Burntboot]

Benji - the oil gauge on your dash is merely a guide, it was never meant to be as precise as people expect.
Senders are notorious for displaying lower pressure at idle and its not uncommon, as they age, for them to start displaying zero at idle.

If you have 12lbs at idle with a mechanical gauge, all is good.
Thicker oil can bridge a wear gap but it can also cause starvation in other parts that aren't as worn.

[Benjie]

Thanks for the reply. My van has no factory oil gauge just a light. I ran a new wire from light to sender that took care of the light coming on and off. Since I was already running that wire I ran a oil gauge sender wire and installed a electronic gauge. I don't like mechanical gauges oil going into my van one more place for oil to leak. When I was young I had a mechanical gauge blow out on me oil all over the dash and floor. Anyone out there run a little thicker oil to help take care of a little bit of a tired engine. I would pull the motor and rebuild it but my Datsun 510 is getting that treatment right now. My van is my daily to work. Thanks again for reply good to know oil pressure at idle is ok.

[Burntboot]

I hear ya on the oil explosion thing, btdt, what a mess.

On DX vans (those without a Tach) the "oil" light actually serves 2 purposes, the "pressure" sender AND the level sender activate the same light.
If you physically ran a new wire from the PS switch to the instrument pack you may have inadvertently disconnected the level sensor.
If it was the level sensor portion of the circuit that was activating the light, that could explain why it doesn't any more.
Those level sensors can fail, causing a false warning, but might be a good idea to check the level, just the same.

The search function can provide all the answers you seek regarding discussion on oil types and ratings.

[Benjie]

Interesting I didn't know about any vehicles from the 80's or before had a oil level sensor. I tied into the oil light at the consol and the other end to the oil pressure senser. Comes on prestart and goes off ounce started. Before I reworded the light it would come on sometimes even if the oil was topped off. Just out of curiosity where would the oil level senser be located. I do like having a gauge I feel like it is a much more solid way of knowing if there is a problem especially since this old van is a little tired.thanks for the info

[Ace MM]

I had a mechanical gauge blow out on me oil all over the dash and floor. Anyone out there run a little thicker oil to help take care of a little bit of a tired engine. I would pull the motor and rebuild it but my Datsun 510 is getting that treatment right now

Plastic line? I've seen that many times.
I have steel braided lines to the gauge in my 510 .
I use higher viscosity oil on old motors.

[Benjie]

Yeh it was a plastic line the gauge was in it when I bought it. I prefer the electronic.

[Gambit]

Hi All -
I'm installing a new mechanical oil pressure gauge this weekend and want to tap into the correct fuse so it lights up when I turn on the headlights / dash lights - would love some insight on which would be best to use. I was going to do the headlights, but was thinking this may have continuous power and is actually not good choice? Any help would be appreciated! EDIT - it's a 12V gauge light.