I have a 90 civic with the d16a6, the temp gauge goes up to half as soon as i crank the car and never moves from there. I have replaced the sending unit on the side of the block and still nothing, i just cant figure out the prob.

 

I can go outside on a -10 degree morning and it will go up 2 half...lol

 

Measure the voltage coming out of the sending unit and see what it reads. You'll have to find the spec for it and find out if you're within range.

 

Yeah, that's why I said measure the voltage. You'll need a spec though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dustin_Pierce &raquo;</TD></TR><TR><TD CLASS="quote">According to my Chilton Helms HONDA Civic/Crx/Del sol repair manual 30200, the spec is check with an ohmeter or 12V light. The switch should normally be open (NO CONTINUITY ACROSS SWITCH TERMINALS) when the coolant temperature is below approxiamately 120 F (49 C). If the switch is closed (CONTINUITY ACROSS THE TERMINALS.) Replace the switch and repeat the check. </TD></TR></TABLE>

Um, no.

Unless you have an OEM manual, or have access to ISIS, I doubt you have the proper procedures for most electrical problems.

Straight from ISIS:

Sender test:

1) Disconnect the YEL/GRN wire from the sender.
2) With the engine cold, use an ohmmeter to measure
resistance between the positive terminal and the
engine (ground).
3) Check the temperature of the coolant.
4) Run the engine and measure the change in resistance
with the engine at operating temperature (cooling
fan comes on).

Temperature: 133* F ["C"Mark] |||| 185*-212* F
Resistance: 142 |||| 49-32 (In ohms.)

5) If obtained readings are substantially different from
specifications above, replace the gauge sender.

Gauge test:

1. Make sure the ignition switch is OFF, then disconnect
the YEL/GRN wire from the coolant temperature
gauge sender and ground it with a jumper wire.
2. Turn the ignition switch ON.
Check that the pointer of the coolant temperature
gauge starts moving toward "H" mark.
CAUTION: Turn the ignition switch OFF before the
pointer reaches "H" mark on the gauge dial. Failure
to turn the ignition OFF quickly enough may cause
damage to the gauge.
If the pointer of the gauge does not swing at all,
check for:
— Blown No. 1 (10 A) fuse in the dash fuse
box.
— An open in the YEL or YEL/GRN wire.
Replace the coolant temperature gauge if the
fuse and wiring are normal.
Inspect the gauge sender if the gauge is OK.

If you're even thinking about using a test light on a vehicle made after 1980, you need to not do electrical work.