Temp gauge reading high. no electric fan(s) operation while engine is running with ac off. both fans do come on when ac is on, but still the gauge reaches the red. No signs of leaks and the the coolant been change within a year. Engine does not make any noise. 40k on the vehicle. This is what i done and replace so far. Replace thermostat and gasket. With engine running temp gauge reading high. 1) jump temp sensor on top radiator hose outlet- no fan action. 2) jump temp sensor at lower radiator thermostat housing - both fans come on. 3) swap power window and electric fan relays - no fan action. With engine off and hot I jump the top radiator hose sensor - radiator fan on the pass side came on. What else can I check. Is there any more relays, sensors or modules that can be tested? thanks for any help you guys can offer.

 

From your description, everything is fine and you have a bad temperature indicator. Either the gauge movement or the sensor is at fault.

Suggest downloading the 91 Accord manual available from Online Manuals links in DIY forum unless you have a shop manual.

If you remove the connector from the temp sensor, short to ground, and turn keyswitch to On, the temp needle should start to swing from cold towards hot. Turn keyswitch Off before the needle reaches full range to avoid damage to the movement. If needle does not move, there is a problem w/ gauge or open in the gauge circuit.

Check coolant temp sensor under and slightly forward of the distributor for resistance. W/ engine fully warmed, the resistance should be 49 ohm(185F) to 32ohm(212F). At cold mark on temp gauge the resistance should be 142 ohms (133F). These are from shop manual. If you get anywhere close, the sensor is good and gauge movement is problem.

good luck