Engine Temp Idiot light..

[Morgonzo]

Where is the sensor located that trips this light? Mine's been on since I bought the truck, and two mechanics have told me not to worry about it, which only makes me worry about it more. The Previous Owner removed the Coolant expansion tank to mount two relays to work the front off-road lights. Is it as simple as this?

 

[crash-harris]

https://www.google.com/search?q=7.3...C&biw=640&bih=335&dpr=3#imgrc=6vuQMmQ7wdneKM:

Missing overflow tank wouldn't trip it. It works off of voltage (or resistance?) and coolant temp. If you're not having overheating problems, then it's probably due to faulty wiring or the switch itself needs replaced.

 

[NJGearhead666]

I would put real gauges in it, I had all these issues when I got my truck and the relief i felt when I saw that I did have good oil pressure and my truck never gets over 180* laid all the worries to rest.

 

[cpdenton]

The light comes on when a heat sensor switch, located near the front of the drivers side cylinder head down by the #2 cylinder exhaust port, grounds out a wire hooked to it.

I will go snap a picture of where the switch is located.

 

[Morgonzo]

Thanks guys, this is one of those things that I was unsure whether it was a stupid question or not. I just went and bought 8 gallons of Fleetcharge 50/50 to flush and fill the radiator, almost 90 bucks I'm so glad the wife expressed her feelings to me that I was spending too much cash on the truck..that made dropping the 80 bucks easier

 

[Morgonzo]

Oh and real gauges are very high on my list..I was trying to explain to the wifey how I needed a Pyrometer even though FMC didn't include one from the factory and she got annoyed because if the maker of the truck didn't spec one, why should I have to spend the dough to buy one now?? (engineers mentality..go figure..) I let the conversation go because I wanted to enjoy the rest of my day but i'm just gonna go and buy one soon.

 

[homelessduck]

Oh and real gauges are very high on my list..I was trying to explain to the wifey how I needed a Pyrometer even though FMC didn't include one from the factory and she got annoyed because if the maker of the truck didn't spec one, why should I have to spend the dough to buy one now?? (engineers mentality..go figure..) I let the conversation go because I wanted to enjoy the rest of my day but i'm just gonna go and buy one soon.

Just tell her it came with one from the factory and it has failed so you need to replace it.

 

[crash-harris]

You've past the telling her you need to replace the pyro. Best way I've found is to lay out the SHTF scenario. Once she understands that if you don't have one you could unknowingly melt a piston and be stuck on the side of the road and have to replace the entire engine No lady enjoys being stuck on the side of the road or being told she needs to submit to months of time and thousands of dollars in repair/replacement.

 

[OLDBULL8]

You can probably find it from this.

 

[Morgonzo]

That was gonna be my plan for the Fleetcharge charge. Think about how little that 80 bucks means when were stuck between Montgomery and Mobile (no-mans-land..) and the kids are crying. If I did have the extra cash for a pyro ($120 ish) I'd be tempted to just go buy that transfer tank instead. Oh, and I just called NAPA and changed my order to the concentrated one for 4 gallons and I'm gonna p/u distilled water. Save a little cash thanks to a post I read by OldBull.

 

[Morgonzo]

Thanks OldBull, I appreciate it. I took some of your advise on the Fleetcharge btw, so thanks for that too!

 

[crash-harris]

Check the link I posted. When I started ID'ing my sensors I used the diagram above and so didn't find it. That's because it's under the A/C compressor, if you have one. It's on the front of the driver's side head. The diagram OldBull posted does show the location of the gauge sender though. It also doesn't show the temp sensor right next to the t-stat housing. That one is only for the cold idle solonoid.

 

[Morgonzo]

Thanks, yeah that picture will Def help because i do have AC. I'm planing a big sunday truck session. Two Injectors need o=rings changed, flush and fill rad and if I can find a long enough drill bit and bolts with out going online..I'm mounting the Hi-Lift Jack to the front bumper. "Sorry honey, i'm gonna be busy all day. Bring back more beer from the store ok?"
Do any of you guys use special o-ring picks with the spoon-like tip? or are you just using the regular pointy tip picks? I'm wondering if this is what keeps cutting my o-rings..or maybe it's just me

 

[icanfixall]

Well it has been pointed out to you the location but here's the way you can test that switch. No mastter what temp the engine coolant is just remove the wire from this sender. Now ground it to any metal. It will cause the dash gauge to peg well past the "L" on the word normal and.. The check engine light comes on. The design of this sender is to tell you the coolant temp has reached 242 degrees and its really too late to cool down the engine. I have not seen many engines that survived coolant tmep excursions past this temp. If you find this sender is failed just leave the wire off it till you replace it. The dash gauge will continue to work fine but you will have no over temp indication.

 

[Morgonzo]

When you say "Check Engine" light, that's different from the "Engine Temp" light right? I'm not trying to be dense, just clarifying it for myself. I'm going to add that sensor check to the master list for sunday. Thanks.