Looking into an aftermarket temp gauge.

i was just curious on the best place to tap into the system to add the coolant temp sensor....

I would like to keep stock sensors and gauges as well...

More or less im tired of not having a clue where my temp actually is besides being between C and H LOL.

 

You are really limited on space to put a temp sender for a temp gauge on a Magnum engine. You can do one of two things: 1) Take out the current temp sender for your factory temp gauge, put it there, and turn your factory temp gauge into a trans temp gauge like I did https://dodgeforum.com/forum/1st-gen...ory-gauge.html (only my factory temp gauge can switch between engine and trans temp). Or 2) Extend your heater core feed hose like I did to install a temp switch to turn on my electric fan. Coolant always flows through you heater core so you'll have accurate temperature readings there https://dodgeforum.com/forum/1st-gen...n-install.html.

 

I dont have a magnum motor... I have the LA 318. the truck is a 91 dakota sport. I would love to keep my stock gauge hooked up (i think it would drive me insane to have a non functioning gauge on the dash) Im also looking to add a temperature switch to run the controller im going to make for my electric fans. (ive been having issues with the cheap store bought controllers only lasting a few months)

Any ideas?

 

There is another option if you are handy, Get some aluminum pipe maybe 3 inches long the same inner diameter as your upper rad hose, drill a hole in the middle of it and tap it the same size as your sensors starting thread, usually they are brass so they are a progressive thread. Cut into your upper rad hose and remove maybe an inch of it, insert the pipe (should be really tight) into the two halves and make sure your tapped hole is to the side or bottom-ish orientation. That way your sensor is able to pick up even if it isn't very long. Use some hose clamps to tighten your aluminum pipe. If you are super handy or have some awesome friends you can add a flange to your pipe or mill it a bit to make it extra tight seal for the clamps. I've seen this done a few times for guys that were installing M1 manifolds. it looks pretty clean if you do it right and usually only costs a few bucks and maybe an hour. If you look around, I think hughes make a piece for this for like 30 or 40 bucks

 

I think i figured out what i want to do for one of them anyway (if not both i need to check on space first) I just seen a heater core hose adapter with a threaded hole for a sensor, thats meant to just splice a 5/8 heater hose. gonna just get a brass 3 way with 2 barb fittings and a bushing to reduce it down to the correct threads for the sender. And i think ill do that for the fan controller, and i may say screw it and part with the factory gauge when i decide to install the aftermarket temp gauge

 

How wide is the gauge? The instrument panel opens up fairly easily and the factory gauge is held in with little more than happy thoughts after you unplug it. You may be able to just reuse the space with little to no modification.

 

The gauges are just the standard 52mm round. I want to leave the stock cluster as it is, and like i said id prefer to keep the stock gauge working.. I will sacrifice the sending unit for the stock gauge but the only way im tearing into the cluster is if im doing all aftermarket gauges. LOL I sure dont have the funds for that one atm.

 

I made my electric fan controller for under $20: https://dodgeforum.com/forum/1st-gen...n-install.html


That's not a good place to put it because it won't read accurate engine temp until after the thermostat opens.


Just make sure it's flow to the heater core and it's not flow from the heater core.

 

Just make sure it's flow to the heater core and it's not flow from the heater core.[/QUOTE]

How do i know which one is the feed line? I have one of those prestone flush things in one of the heater core hoses already (was there when i bought it)

What size is the heater core lines on these trucks?


Im going to get a relay and just wire it with a temperature switch. I also want to wire a full on feature (for off road and such) Do i need a special relay for this? (my fans pull just under 40amps at startup)

I think i may do the junkyard volvo relay as you did, but id hate to have to buy a 50 dollar relay after that too (if it fails) i suppose i could snag a couple at the jy as well.

 

Take off both heater core hoses and start your engine to see which one blows coolant all over your engine making a mess. Just kidding. It's usually the one closest to the thermostat.

Usually 5/8".

You shouldn't need a separate relay. Use the ground to turn it on. You can have the same terminal ground the relay or have a manual switch ground the relay.