1994 E-350 7.5L 460
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 159
Likes: 2
From: Maryland
Thanks again guys,
Frozen_Joker, I have replaced the fan speed switch that is in the dash, that was the last thing I replaced. It looked a little cooked...hmm I wonder if the wiring was damaged? But then why would it work intermittently? I will check the grounds to see if any rust might be causing this.
Thanks for all the responses. I will check it out again today.
Semper Fi
1994 E350 460 Callista Cove 28' RV
Frozen_Joker, I have replaced the fan speed switch that is in the dash, that was the last thing I replaced. It looked a little cooked...hmm I wonder if the wiring was damaged? But then why would it work intermittently? I will check the grounds to see if any rust might be causing this.
Thanks for all the responses. I will check it out again today.
Semper Fi
1994 E350 460 Callista Cove 28' RV
Tuned
Joined: Sep 2010
Posts: 473
Likes: 0
From: Farmington, MO
The diagram is accurate. All of the Fords I have worked on for 40 years have work the way the diagram says.
I was unaware if you had or not. And you are positive its good? There is a possibility of a nasty wire behind the dash somewhere. Never can fully rule that out. Lol.
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 159
Likes: 2
From: Maryland
Thanks guys I will start the task of checking everything for continuity, etc. I just have to get me a good multimeter, my old one died. Thanks for your time and suggestions!
Semper Fi
Semper Fi
Fleet Owner
Joined: Aug 2010
Posts: 21,253
Likes: 1,656
From: Reynoldsburg, Ohio
PM me.
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 159
Likes: 2
From: Maryland
Ok, so I finally had time to mess with this again. I pulled out the Blower motor resistor. How do I check it to see if it actually is bad? The thermal limiter is pretty black but do not know how to properly test it.
Thanks!
Semper Fi
Thanks!
Semper Fi
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 159
Likes: 2
From: Maryland
Thanks JWA, I did see that but am not 100% certain how to translate it into actual hands on testing. I wanted to test the resistor while it is out of the truck if possible. Thanks again
Semper Fi
Semper Fi
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 159
Likes: 2
From: Maryland
Ok, so I tested the items discussed in this thread by following this tutorial Part 2 -How to Test the Blower Control Switch (Ford 4.9L, 5.0L, 5.8L).
When I took the blower motor switch out to test I found another harness in there as well (the one on the left). What is this one for? Anyway, it looks like from my testing that the switch is bad, there was no continuity on some of the settings. The resistor tested fine. But what still perplexes me is that sometimes it would work just fine, then quit. Could the harness/pigtail be going bad? The original switch had some burn marks on it.
<iframe src="https://www.flickr.com/photos/25801635@N00/13092502344/player/b4159bcc0d" height="500" width="375" frameborder="0" allowfullscreen webkitallowfullscreen mozallowfullscreen oallowfullscreen msallowfullscreen></iframe>
When I took the blower motor switch out to test I found another harness in there as well (the one on the left). What is this one for? Anyway, it looks like from my testing that the switch is bad, there was no continuity on some of the settings. The resistor tested fine. But what still perplexes me is that sometimes it would work just fine, then quit. Could the harness/pigtail be going bad? The original switch had some burn marks on it.
<iframe src="https://www.flickr.com/photos/25801635@N00/13092502344/player/b4159bcc0d" height="500" width="375" frameborder="0" allowfullscreen webkitallowfullscreen mozallowfullscreen oallowfullscreen msallowfullscreen></iframe>
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Fleet Owner
Joined: Aug 2010
Posts: 21,253
Likes: 1,656
From: Reynoldsburg, Ohio
At this point I'm not 100% clear on your skill level to follow a schematic and interpret the findings as to which component or circuit is giving you the problems. Please know that's not meant to be an insult at all!
The intermittent operation suggests the switch----its not an uncommon problem.
IF the connector for the front only blower looks melted or discolored replace it. Along with the switch these seem to be subjected to high amp loads and tend to fail at some point. NAPA etc have replacement pigtails specifically for that need---give them the application and they'll have or order the right part. Other parts sellers no doubt have these too but I use NAPA quite frequently.
The switch is also available aftermarket too.
The second connector you show in above photo is an unused connector for a rear blower. Without the appropriate dash control pod there's no place for the second connector to attach but it doesn't have any live power in it anyway, not really a concern.
HTH
The intermittent operation suggests the switch----its not an uncommon problem.
IF the connector for the front only blower looks melted or discolored replace it. Along with the switch these seem to be subjected to high amp loads and tend to fail at some point. NAPA etc have replacement pigtails specifically for that need---give them the application and they'll have or order the right part. Other parts sellers no doubt have these too but I use NAPA quite frequently.
The switch is also available aftermarket too.
The second connector you show in above photo is an unused connector for a rear blower. Without the appropriate dash control pod there's no place for the second connector to attach but it doesn't have any live power in it anyway, not really a concern.
HTH
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 159
Likes: 2
From: Maryland
No Worries JWA I am not insulted. I am a novice at this hence me asking these types of questions on forums like this. I would rather try to figure something out myself (with a lot of help from kind folks like you, Sub_Ford, Frozen_Joker, etc) and learn from it than to automatically take my vehicle to a dealer to get it fixed. Being that my E350 is also a 28' motorhome helps in that department for not all dealers can service these things. Like in the Marine Corps, I had to know my equipment but that knowledge did not just happen.
When I first replaced the switch it was burned but the pigtail/harness was fine. I also got a new battery for the beast, crazy cold winter killed the 5yr old one. I think I read somewhere on this site someone experienced something similar after replacing a battery. Anyway I will replace the switch again and see what happens. This WILL get fixed!! haha
Thanks again for your candor and helpful suggestions.
Semper Fi
When I first replaced the switch it was burned but the pigtail/harness was fine. I also got a new battery for the beast, crazy cold winter killed the 5yr old one. I think I read somewhere on this site someone experienced something similar after replacing a battery. Anyway I will replace the switch again and see what happens. This WILL get fixed!! haha
Thanks again for your candor and helpful suggestions.
Semper Fi
Thread Starter
|
Senior User
Joined: Oct 2002
Posts: 159
Likes: 2
From: Maryland
Success!!!! So after double checking all the parts I still had this nagging feeling that everything was good and that a loose wire/connection was the culprit (as subford and others suggested early on). To me, this would explain the intermittent working perfectly fine and then quitting. So I decided to go high tech, I popped the hood turned the ignition to on, turned the blower to vent/med and started wiggling wires under the hood. Well wouldn't you know it the harness/connection to the Relay was loose; Wiggle it and the blower turns on, tap it and it goes off. A quick tightening/re-seating and now the thing is a go all the time!! I guess I felt I did not need to check that area since the part was relatively new. Thanks for all your help and patience guys!! Lesson learned :-)
Semper Fi
Semper Fi
Fleet Owner
Joined: Aug 2010
Posts: 21,253
Likes: 1,656
From: Reynoldsburg, Ohio
That too! 
Good gravy the number of times I've wanted to take a hammer or other tool of destruction to aspects of my work---and I'm in the glass biz!
Good gravy the number of times I've wanted to take a hammer or other tool of destruction to aspects of my work---and I'm in the glass biz!
New User
Joined: Jan 2006
Posts: 2
Likes: 0
HI I can't help you with your ac problem, but maybe you can help me. I just drove one I picked up in Va. and drove to Cocoa Fl and it ran like a top some thing you have. But I can not find the fuse box. It is not under the dash like the manual says. Not under the hood the power box is there but not the fuse box. Can anyone HELP? Thanks Jake
