temperture gauge

[seattlestiva]

Hey All - One constant in the last year has been the temp. gauge. It never goes above maybe a quarter up. Summer, winter doesn't matter. Radiator's fine. Replaced the thermostat with the Mazda one. I get plenty of heat.
So, not a biggy practically speaking, but just curious. Anything obvious?

[Damkid]

The temp gauge works on the amount of resistance the sensor has depending on it's temperature, the less resistance, the higher the needle goes on the gauge

IE, if you took the temp gauge wire and grounded it out, the needle will climb to red hot

So if there's a bit of corrosion at the connector, it would create more resistance not allowing your heat gauge to climb as far as it could potentially, so you could try cleaning it up a bit to help get the needle to climb a bit higher

[walth]

^^ rep points FTW

I didn't know they were resistance designed. cool

[JoDan]

This must be an common problem because every festiva I've ever seen just went above the cold mark. Last weekend I installed a new temp sensor since it was leaking and cleaned the contacts and now the needle is right in the middle.

[walth]

I totally agree. most people probably think they don't have any issues with the cars cooling system, not knowing how it works and how that oil and grime messes with it over time. ignorant negligence...I didn't know either I'll clean up as much as I can before I install my b6 so I know what I want to fix on my b3 for later. that'll be one of the first things I get working right as I'm sure it's not correct either.

awesome thread

[JoDan]

Cool beans... now I just gotta figure out the fuel gauge because when I filled my car up today it only read just above half which is difficult to diagnose since I just put in a tach cluster this week so I'm not sure if it's the sender or the cluster but my old cluster only read about 7/8 when full so I'll swap out the sender and see.

[neanderpaul]

When I bought my first 5 or so festys they were all newish (2 - 5 years old) with original t-stats. They all ran between 1/4 and 1/3 on the temp gauge. Sounds perfect to me. I can never get above 1/5 now even with the murray two stage. But that's still an improvement over just below operating range. I get good heat either way.

[TominMO]

I ditched the stock temp gauge in my tach cluster, to install another speedo, and am using an aftermarket temp gauge. Even with blocking off most of the grill and all of the bumper openings, my temp gauge reads about 165 while the car is moving, and only goes up to 180 - 190 when standing still. New dual-core radiator and the better Stant thermostat in the car.

[Damkid]

^^ rep points FTW

I didn't know they were resistance designed. cool

Thanks, I only learned that from when I wired up my temp gauge for my V6 lol

[Pu241]

Yeah, device is call a thermistor.
I've found that the connector on the wire itself causes issues.
Best solution so far is to cut the connector off, tin the wire itself and solder it directly to the sensor.
Sensitivity and range of the gage are greatly improved.

[walth]

that's a great idea, thanks

[seattlestiva]

Just to reconfirm - The temperture gauge sensor is the one with the single yellow wire. Not the one with the red/green wire (black connnector).
'88 LX