TheSamba.com :: View topic - Thermometers and where to place an ambient temperature probe?

Tue Mar 30, 2021 4:59 am

This recent thread jump started my brain on installing an outside thermometer in the Van.......

https://www.thesamba.com/vw/forum/viewtopic.php?t=752108

I've actually already ordered one that appealed to me.

https://www.amazon.com/gp/product/B01H1RDJOI/ref=ox_sc_act_title_1?smid=ASJH2J1X3O61S&psc=1

It is powered by a 5v USB plug rather than 12v.
It has a hard C° / F° switch on the back
I will be wiring in a bank of USB plugs behind the dash glovebox. This bank of plugs will be powered by 12v ignition.

https://www.amazon.com/gp/product/B08MCZNYZN/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

These plugs will feed my phone charger, my on dash mounted GPS, this thermostat and ?? Who knows.
It is important to me that the thermostat remember its display range, so many digital items seem to default to C° upon restoration from a power loss.

I've been toying with the best temperature probe location.
Many vehicles have them by the hood latch in front of the radiator.
I was thinking of behind the headlight assembly?
Somewhere out of the Sun, not in the path of post radiator air flow, easy to access.
The cooling fan resistor is by the left headlight, I wonder if that will affect readings?

Dave

Tue Mar 30, 2021 5:13 am

i know you've bought yours already but i buy a rectangular AA powered therm to eliminate a cord and then tuck it in the left side of the dash/windshield area. run the temp probe out the door hinge area and use some 3M VHB double tape to tape the sensor to the antenna mast or drip rail.

i really like an outside thermometer and have them in every vehicle including my old Mercedes. at the sensor location described above, it'll be inaccurate if parked in the sun but it cools off quick. there is SOME sun influence while driving but generally a 60mph breeze removes solar heat about as quick as it is added. but it nudges up a bit if the sun is on the drivers side.

Tue Mar 30, 2021 5:56 am

I use a unit with remote sensors. I place one in a double zip lock bag and zip tie it to the side of a frame member under the bus. No influence from the sun or radiator or hot bus metal. Battery lasts at least a year.

Tue Mar 30, 2021 6:13 am

I have a wireless indoor/outdoor unit in the high-top area and the remote sensor/sender is in a zip lock bag ( :D ) in a covered spot on the rear RMW swingout.

A second indoor/outdoor thermometer (just for fun) is mounted on the dash with the probe wire running behind the air vent cover, out through the big rubber grommet in the floor and over to the space between the body and the windshield washer bottle. Both areas chosen for dryness, air circulation and away from direct sunlight.

I like the usb outlet you've selected. I'm cleaning up wires, installing a new head unit and adding outlets now too.

Here's the wireless indoor/outdoor thermometer. I like the recorded temps for highs/lows for the past 12, 24, 72, and since last reset. This was a temp from this winter when I needed two electric space heaters to keep my wfh office (the van) warm.

https://www.amazon.com/gp/product/B00WXIR8SO/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1

Here's the $10 indoor/outdoor thermometer bought from Uniwerks design. It's a perfect fit for this place in the van.

https://www.uniwerksdesign.com/product/inside-outside-thermometer/

Tue Mar 30, 2021 6:18 am

My PO put it between the driver side headlight and radiator. (Take off the upper grill, find a grommet to poke the wire through). Works good.

Tue Mar 30, 2021 6:23 am

Thanks for the ideas.

I dislike wires sprouting forth out of the dash!

Steve had replaced the lighter port with two always on USB ports.
My phone and GPS are currently plugged into that.

I will be installing Brickwerks gauge pod in the ashtray hole on the dash.

The GPS is in front of the driver, I place my phone on the dash to the right of the cluster so two short wires out of the gauge pod will keep things neat.

I hope to mount the thermometer in the dash somewhere.
I need to actually see the unit and evaluate its best location.
If it fits in the switch blank above the rear defroster switch, that would be great but night time brightness will be a concern there.

Dave

Tue Mar 30, 2021 6:25 am

Dave--i run my outside temp probe behind the front bumper on the extreme left corner away from the coolant hoses. The bumper is a silver fiberglass one and so picks up only modest gain gain when parked in the sun which soon stabilizes with the breeze of driving. Seems close enough. The readout is right at the instrument cluster and the wire sneaks down somehow behind everything and outside, but can't remember just now. Couldn't have been too hard.

Its a dual temp/probe F item and the inside temp is located above the RV mirror.
https://www.amazon.com/gp/product/B07WS11X45/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

Duncan

Tue Mar 30, 2021 6:36 am

I too have the fiberglass bumpers, that is a really good idea!

Your rearview mirror comment made me remember that when I stripped the 2000 something dodge minivan that I pulled the compass/temperature rear view mirror and all of its sensors!
Hmmmm....... I may be returning a thermometer!
Temperature AND direction!

Dave

Tue Mar 30, 2021 7:26 am

My probe is behind the grill near the driver's side headlight. Wire runs to receiver which is located in the ashtray. Battery lasts a couple years. I use those Acu-Rite meters to check the fridge temp as well as the temps of my garage freezers.

Tue Mar 30, 2021 7:57 am

djkeev wrote: Thanks for the ideas.

I dislike wires sprouting forth out of the dash!

So, like those holes in the firewall with grommets for wiring in front by the headlights? Or, in the cabin?

Tue Mar 30, 2021 8:30 am

I'd like it in the intake. Might as well know what the air temp is going into the engine. The outside temp is what it is. Not sure why that knowledge is so important. Its either "Too Hot", "Too Cold" or "Perfect".

Tue Mar 30, 2021 8:31 am

My wife wants to see outdoor temps too.

If you had one INKBIRD tem controller you could A/B/C switch between several temp sensors for "trans / outdoor / fridge."
Probably better just to buy 3 INKBIRDs then you have spares.
But if you are using the INKBIRD relays the unit will 'take actions' when you switch A/B/C.
Also note that using it for fridge temp is easier said than done.
See this thread: Truck Fridge Digital Thermostat
Refrigeration techs have a better understanding how the compressor delays etc work with a controller.

Look at the INKBIRD store on Amazon, they offer all kinds of crazy units, some with phone apps, datalogging, and some with four displays.
Some with wireless sensors that don't need a wire.

Mark Inkbird has stainless steel temperature probes.
You could drill a small, tight hole in a rubber intake part and poke the probe in, it would seal tight.

I'd like to monitor EJ25 engine sump oil temperature next.
I suspect high oil temp is why my EJ25 "seems" to start gulping oil after 3 or 4,000 miles.
There's only one way to find out.
For oilpan, you could drill a little hole and epoxy the sensor directly into a hole.
Then later you can enlarge & thread the hole for a proper screw-in sensor etc.

Tue Mar 30, 2021 9:01 am

I put my probe just behind the passenger side headlamp. This is a cheap button-cell powered in/out thermometer, $7 from Pep boys. Industrial Velcro'd to just under the radio.

Tue Mar 30, 2021 2:02 pm

Multiman MV installed the same unit in his van on the steering column. Maybe see where he ran his probe. I know the wire isn't too long. I have the same one too and bought two units so I could splice the probe wire and get twice the length.

Tue Mar 30, 2021 2:10 pm

MarkWard wrote: I'd like it in the intake. Might as well know what the air temp is going into the engine. The outside temp is what it is. Not sure why that knowledge is so important. Its either "Too Hot", "Too Cold" or "Perfect".

I freely admit that I'm a weather nerd.

I have a full weather station at my house.

Have an outside temperature reading is just a small luxury.

Dave

Tue Mar 30, 2021 2:20 pm

we can have 90F temp swings in 36 hours in MN. there's a threshold, each car is different, where you know it will start and where it won't. in the north, it's useful info partly because it relates to life or death and partly a point of pride. yes, ya already know the weather before you go to start the cars. however, on the Mercedes, at 14F i know it will pop right off. 7F, it's gonna struggle.

but i MOSTLY like a thermometer to see the temp differences as one is driving... low spots, high passes, going thru towns. "LOOK! It dropped TWO degrees right here!" ayup, it is truly exciting conversation in our travels.

Tue Mar 30, 2021 3:10 pm

Where I live an outside temp gauge can be useful to know if there is a risk of ice on the road.

Tue Mar 30, 2021 3:31 pm

harvgwen wrote: Where I live an outside temp gauge can be useful to know if there is a risk of ice on the road.

That's part of it, most of my cross country travel is in the Fall and late Fall.
One time I left NJ in shorts and sandals and arrived in Great Falls Montana at -09° F a few days later!

Should I put slippers on to get gas or go barefoot?
I drive barefoot 365 when I can.

Dave

Tue Mar 30, 2021 4:50 pm

Here's my ambient temp gauge in it's little home. The sensor is behind the front bumper.

Tue Mar 30, 2021 6:43 pm

Headlamps put out a lot of heat when they are on. I nixed that location. YMMV.