BullnoseLuvr Posted August 7, 2020 Share Posted August 7, 2020 As a step in rebuilding my A/C I pulled the evaporator out today and a considerable amount of vegetable matter poured out of the blower box and the resistors were completely encased in debris. The evaporator didn't look especially dirty but I couldn't see much light through it. I installed the new evaporator and buttoned everything back up and whoa nelly! That thing blows like a... well, it blows really hard. Like amazingly hard. I don't know if it was the debris, a dirty evaporator, or both but it's a dramatic improvement -- enough that I'm not going to bother doing the relay mod. If you pull the blower and clean the box and don't get good results it might not be a bad idea to pull the evaporator out and wash hell out of it with a strong nozzle. Fortunately it's possible to pull the evaporator and swing it out without discharging the system. I'm going to measure airflow at each of the vents with my anemometer (pictured below) and report back. Mark Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 7, 2020 Share Posted August 7, 2020 Now, if you'd just go measure Scott's or Jim's air flow with their relay mod's we'd know how much improvement they make. Of course, that's assuming their evap's aren't clogged. Link to comment Share on other sites More sharing options...
1986F150Six Posted August 7, 2020 Share Posted August 7, 2020 Now, if you'd just go measure Scott's or Jim's air flow with their relay mod's we'd know how much improvement they make. Of course, that's assuming their evap's aren't clogged. Too bad you did not measure the air flow before the work you have done, for a true comparison. Good work! Link to comment Share on other sites More sharing options...
kramttocs Posted August 7, 2020 Share Posted August 7, 2020 Now, if you'd just go measure Scott's or Jim's air flow with their relay mod's we'd know how much improvement they make. Of course, that's assuming their evap's aren't clogged. In the name of science I just ordered one of these. I replaced my evap and have only had the fan on for at most 6 hours of highway driving. Otherwise it has been windows down since the un-modded vent setting is hot. Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 7, 2020 Share Posted August 7, 2020 In the name of science I just ordered one of these. I replaced my evap and have only had the fan on for at most 6 hours of highway driving. Otherwise it has been windows down since the un-modded vent setting is hot. That's a really neat tool! I'm jealous. Link to comment Share on other sites More sharing options...
BullnoseLuvr Posted August 7, 2020 Author Share Posted August 7, 2020 Too bad you did not measure the air flow before the work you have done, for a true comparison. Good work! I would have had I known replacing the evap would make such a change. Mark Link to comment Share on other sites More sharing options...
FuzzFace2 Posted August 7, 2020 Share Posted August 7, 2020 I would have had I known replacing the evap would make such a change. Mark In a regular cab I don't see the need to have the fan blow more than it does. I turn the fan on high when I first get in after work because it is hot, 90*+ OAT but once the cab is cooled down I cut the fan speed back. Dave ---- Link to comment Share on other sites More sharing options...
BullnoseLuvr Posted August 7, 2020 Author Share Posted August 7, 2020 In the name of science I just ordered one of these. I replaced my evap and have only had the fan on for at most 6 hours of highway driving. Otherwise it has been windows down since the un-modded vent setting is hot. Welcome to the rabbit hole... Mark Link to comment Share on other sites More sharing options...
kramttocs Posted August 7, 2020 Share Posted August 7, 2020 In the name of science I just ordered one of these. I replaced my evap and have only had the fan on for at most 6 hours of highway driving. Otherwise it has been windows down since the un-modded vent setting is hot. Welcome to the rabbit hole... Mark I don't know if we ever full crawl out of the rabbit hole but I was meaning that my system is the same as new so the test should be comparible. I can also test without the relay for comparison on the same truck. Then throw in the ground relay and we can compare all of it. Honestly never knew such a device existed. Glad you showed it. Link to comment Share on other sites More sharing options...
BullnoseLuvr Posted August 7, 2020 Author Share Posted August 7, 2020 In the name of science I just ordered one of these. I replaced my evap and have only had the fan on for at most 6 hours of highway driving. Otherwise it has been windows down since the un-modded vent setting is hot. Welcome to the rabbit hole... Mark So I measured my airflow with the engine at 1500 rpm, all accessories off and controls on MAX A/C with no compressor since the system isn't finished yet. These numbers are meaningless since I didn't take "before" measurments but they might be of interest to the next person who measures his truck vent airflow with an anemometer. The pics are the vents left to right in two passes, 8 pics total. I apologize for the sidewaysness but I'm just not up to rotating the pics. Mark Link to comment Share on other sites More sharing options...
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