Dandxj Posted September 1, 2022 Share Posted September 1, 2022 1990 4.0L Renix - This truck is new to me and I have a few questions about the dash warning lights. First: At what temperature does the temperature light go on? Likewise at what pressure would the oil pressure light go on? And at what voltage would the Battery light go on? Second: I know the temperature and pressure are triggered by switches, but what triggers the voltage (Battery) light? The ECU? Third: When I turn the key to ON the oil pressure and battery lights light up but not the temperature light. If I ground the temperature switch connector the light comes on, so the bulb is OK. I am assuming it should light up like the pressure and voltage lights when the key is first turned or am I missing something. Thanks Link to comment Share on other sites More sharing options...
jdog Posted September 1, 2022 Share Posted September 1, 2022 The oil light comes on when there is little to no oil pressure, the temp light comes on at something like 220 degrees. and the battery light is like 11.5volts. the oil and battery come on as there is no pressure/voltage when key is first turned on. the temp does not come on unless the unit is overheating. Link to comment Share on other sites More sharing options...
eaglescout526 Posted September 1, 2022 Share Posted September 1, 2022 33 minutes ago, jdog said: the temp does not come on unless the unit is overheating. Actually it does come on during the “gauge test” when you crank the engine over. Not sure why it was done like this but when you crank the engine over the temp gauge/light circuit is grounded and serves as a test function for that and that alone. Battery nor oil get such a test. Link to comment Share on other sites More sharing options...
jdog Posted September 1, 2022 Share Posted September 1, 2022 5 minutes ago, eaglescout526 said: Actually it does come on during the “gauge test” when you crank the engine over. Not sure why it was done like this but when you crank the engine over the temp gauge/light circuit is grounded and serves as a test function for that and that alone. Battery nor oil get such a test. it's been a while since i had that cluster, thanks Link to comment Share on other sites More sharing options...
eaglescout526 Posted September 1, 2022 Share Posted September 1, 2022 59 minutes ago, jdog said: it's been a while since i had that cluster, thanks No problem. It does it to the gauges too but oddly enough I remember my idiot light cluster very well. Kinda miss it sometimes. Link to comment Share on other sites More sharing options...
Dandxj Posted September 2, 2022 Author Share Posted September 2, 2022 Thanks for your comments. I will check for the temperature light while cranking after I attend to my starter relay issue. I guess if the temperature switch does not close until 220 F I have no way to easily test it. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now