A couple weeks ago I posted about a D15B2 I had put into a Civic Si that was "overheating" (gauge pointed to the H)
So after a lot of troubleshooting I figured out it was the coolant temp sensor.

Here's the deal this time:
1989 CRX SI
D15B1 on MPFI
Car is reading Hot
-Checked Coolant Temp Sensor wiring, it sends signal just fine
-Replaced Coolant Temp Sensor with 3 for-sure working sensors

As soon as I turn the ignition to the 2nd spot, the temp gauge goes halfway up. So I know its not a problem with the fan or anything, it just automatically thinks it's hot.

Could the thermostat have anyhting to do with this?

thanks guys

 

Did you replace the one under the dizzy?

If you did, I do believe there is a couple on the backside of the block that control the actual gauge in your dash...

I did a search a few weeks ago on this and came up with some pics...I'm sure you could do the same and find them if you didn't replace the ones on the back of the block...

Hope this helps...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimmyM86 &raquo;</TD></TR><TR><TD CLASS="quote">Did you replace the one under the dizzy?

If you did, I do believe there is a couple on the backside of the block that control the actual gauge in your dash...</TD></TR></TABLE>
the one under the dizzy is the Coolant Temp Sensor, and I replaced it 3 times

The one on the back is the Thermo Sensor, and it controls the fan, and I havent changed it out yet. But I dont think its related to that because the gauge reads funny regardless of whether its hooked up or not

 

Sounds like a bad ground somewhere. Have you checked the condition of the connector to the sensor? Checked the wiring? What are the condition of all of your grounds?

 

All grounds (neg. cable, thermo housing, and tranny) are freshly ground to bare metal for perfect contact.

The wire for the coolant temp sensor is sending signal perfectly fine, I checked it as told to by the CRX Shop Manual.

To my knowledge all the wring involved is fine, I dont know if anything related to the cluster itself could be causing a problem?

 

bump, i need input here fellas

 

So I put in a new gauge cluster, problem still there.

Even when my Coolant Temp Sensor is unplugged, and I turn it to the 2nd ignitions spot, the gauge starts rising to the middle, and then if I plug it up it jumps to the H.

so im thinking this is bad wiring, can anybody point me in the right direction on what to do here?

 

for the love of god will somebody TRY and help me here?

 

On my b series I have a coolant temp sensor and a coolant temp sending unit. I had a short on mine before so have u checked all your fuses, and secure wiring with no breaks or shorts? Test your sending unit with the ignition on but not running by grounding the wire to see if your gauge deflects full scale, this will tell you your circuit is ok so replace your sending unit.

 

Also u could rebuild the wiring harness, That will give u positive thought because you would probly find a crack in the wires casing or someone elses shitty soldering job who used 5 diff. gauges of wire and 5 halffast connections that looked to be made by a 7yr old (that was my case)