Howdy from sunny Northern Alabama. I tried a search, incl. in the FAQ section but could not find this topic, I have a Chiltons manual but it's no help in this area. Several months ago I noticed the coolant temperature gage in my 1995 Accord EX was a bit slower to reach normal operating range after start up. A few weeks later I noticed it would no longer climb up to the normal range, but consistently fell short (e.g., reading cooler than normal). So I changed the thermostat. No change in the gage's behavior. Hmm. Another few weeks go by and it barely rose off the peg regardless of how long I drove the car, and indicated even lower (cooler) than before. Finally it stopped moving completely. Dead. Stuck on the totally cold peg. So I replaced the coolant temp sending unit. No change in the gage behavior. Hmm. So I replaced the gage in the pod with an new one ($ouch, plus a real risky pain in the petut to pull everything apart). Durned if that expensive new needle is as dead as the original one. I went to the local Honda dealer once a few years ago for something else and will never make that mistake again. Anyone got any ideas? Bad printed circuit board in the gage pod? Is there more than one sending unit feeding the temp gage? It's about to be summer in Alabama and I don't wish to drive with an inoperative coolant temp gage.
Thanks,
Jim

 

That is interesting... you already took the steps I would've suggested. Did you use a Honda sending unit? I got an aftermarket BWD after I sheared the plug off of it and now my gauge consistently reads 3/4 for operating temp and loves to fluctuate.

If it doesn't get fixed by summer, I think you'll be fine knowing you have a new thermostat and fresh coolant in there.

 

Did you change the right sender? The sender for the gauge is in the head & it only has ONE wire. The 2-wire senders are for the ECU & fan switches.

 

Right - as JimBlake mentioned - there is a gauge temp sending unit, and then there will be an engine coolant temp sensor... two different parts. You should be able to bench test the gauge sending unit, as well as check for voltage at the harness at the back of the cluster... if you have correct voltage at the cluster then you have a bad instrument cluster.

 

first off chk fuse # 1 10 amps under dash fuse box,, if ok, go to the coolant temp sending unit , as mentioned ,it has 1 wire, i believe it is yellow/green , unplug it from the sensor , turn the key to on position and ground the wire,, do not let it go all the way to the H ,, It is easier to have someone look at the gauge while another grounds the wire

if needle on the temp gauge does not move, you got bad wiring ( most likely an open ) from sensor to gauge or a bad gauge
if gauge moves slowly and creeps up to H you got a bad sending unit

Hope this helps solve your issue

 

Thank you all so much- upon reading your replies I went out and sure enough, I had replaced a two wire sending unit. I grounded the single wire as deserthonda suggested and got an immediate climb on the gage needle when I switched on. I'll be ordering a replacement now for what we like to call the correct sending unit. Appreciate all the help!
Jim

 

Just to follow up, problem solved. It's a small single post sending unit and took about five minutes to replace. Thanks to all!

 

Good deal. Thanks for telling us the final result. Lots of people just disappear & we never know if our advice was any help.