1995 Grand Marquis luke warm heat
 

New to me 95 GM and on first cold day I just discovered has Luke warm heat. I flushed radiator and changed tstat (with stock 195) but no help. Temp gauge reads normal, coolant full and EATC seems to be working ok. Diag mode only pulls an intermittent 025 code but I can hear doors moving so thinking its not blend door. Car only has 69k miles could it be clogged heater core or what else? Also anyone know if EATC in 1995 had replaceable bulbs vs soldered behind l the face plate? Thanks!

Anyone have thoughts on this? I recently put in a rebuilt eatc and it works great except we still have luke warm heat which is a problem when it's 15 degrees out. Am I faced with a blend door replacement?

Check both heater hoses, they should get very warm. If they do, look for a blend door issue. Sorry, I am not familiar with your bulb style but would be very surprised if they were soldered in.

Thanks for suggestion. Top heater hose is hot bottom one not as much but I flushed out heater core last year and found no obstruction. Looks like I'll be pulling the airbag out and checking the blend door functionality. AC isn't the coldest either so maybe the blend door is only moving part of the way without ever fully opening or closing

If that other heater hose is more than slightly cooler than the other, I would be flushing the heater core first.

I flushed heater core last year and it had great flow. I don't think the coolant line coming out of the intake manifold has as much pressure as a garden hose though. If I didn't know better I would think there was an air pocket somewhere but the coolant level is full and the thermostat was replaced with a stock unit. Because I get heat increase when adjusting eatc between 60 and 75 and hardly any change between 75 and 90 I'm thinking the blend door may not be working properly however there are no codes stored in the eatc currently. Oh and eatc was also replaced with a rebuilt unit.