Fan keeps quitting

[Blacktank]

some options to check out
https://www.ebay.com/itm/1988-Ford-Econo...1171576705

https://manuals.co/workshop/ford/econoline

https://www.amazon.com/REPAIR-MANUAL-INC...B00H5TBEZO


i dont know about ford but gm will use the same controls in trucks and vans

[MN C Van]

Library's may have subscriptions.

I'd just go to a junkyard and pull it- and any other little things you need while you're there

[RoamingKat]

The alldatadiy has no search ...

The form to ask for help requires I be a member of alldata.

Still don’t even know if they have it. Looked thru the tab items, but once I get to diagrams, etc...it isn’t a clickable item. Cannot see how anyone got any info from them without giving alldata money and/or personal data first. I give up on that website.

[Motrukdriver]

Go here, find the appropriate forum and ask your questions:

https://www.ford-trucks.com/

[RoamingKat]

I found the part...on vanderhaggs.
But, it turns out that the fan switch is actually a completely separate part, held together with the whole panel with just a screw. So, once swapped out, all is well.

[sternwake]

The HVAC fan speed selector Switch on my Dodge had serious issues, the fuse powering it was melted out when I got the van.

It was often blowing the 25 amp fuse, and I went through many fuse holders and fuses before taking the dash apart and opening up the switch itself. it one point i had defeated the top fan speed as the metal lever would get so hot it could burn my fingers.

The speed selector switch itself has a little copper plate which would slide and bridge certain contacts for different fan speeds, and all the mating surfaces were covered with a crusty black goo. Once cleaned and the spring expanded to exert more pressure all problems disappeared, for a few years.

But I knew what the problem was when it cropped back up and another cleaning solved it again, temporarily, meaning a few years.

Eventually my blower motor itself started making all sorts of ugly noises when cold, and it was time to service the whole circuit.

The new Blower motor got fed with 8awg, as I had no 10AWG available. Original was 14 SAE gauge. the connector at the fan switch was in very bad condition, melted wire insulation. The connection at the resistor pack, one tang had rusted off.

The inside of the switch itself was not bad but still got its contacts polished.

I cut off the original connector and ran individual wires to each spade connector, but later saw rockAuto had a new connector pigtail and a new switch itself was also very reasonably priced, but I was not waiting a week for delivery, the dash was open.

Long story slightly shorter the new blower motor gets significantly more voltage, and spins much faster than before. Higher voltage is less stressful on connectors, which were now less resistive to electron flow.

the blower motor now moves as much air on medium high as it did previously on High, and high speed is a bit nutty and reveals restriction in the ducting itself

While I kept the original speed control switch and circuitry, if I were to do it over, I would use a 21KHZ+ PWM motor speed controller rated for at least 20 amps, and bypass most all of that problem stock wiring, and instead of 4 set speds there would be infinite speeds avalable between minimum and max.

The 21KHZ frequency of the PWM signal makes the motor not humm audibly to human ears, though Fido might be annoyed by it. many PWm motor speed controllers are 13KHZ and will irritate the Shite out of anybody with OK hearing, at reduced speeds.

The blower motors themselves can draw 15 to 18 amps when new, and Very few DC switches are rated to carry more than 15 amps. When the circuit feeding the motor gets old the voltage drops but the motor is still desiring the 12 volts it was designed for, as a result the amperage increases on a circuit that was basically maxed out when it was new. and healthy, not with ancient wire and oxidized connectors overheated dozens of times.

Add to this the blower motors do not use ball bearings, but have bushings, with a felt sleeve designed to keep any originally sparsely applied lubricant in place. This works as well as expected(very badly) and without drilling a hole on each end of the motor to be able to regularly inject lubricant, there is no way to improve the blower motors. it is not a traditional sleeve bushing which might have a ball bearing option, even if the motor could be reassmebled with brushes in place without the curse fest to end the mother of all curse fests.

So once that Lube is dried out, the blower motor will start pulling more and more amperage until the bushings start making hideous noises indicating replacement can no longer be put off.

It is the max speed settings of the blower motors which are most stressful on the circuitry, so keeping it off of maximum can prevent having to deal with possibly complicated replacements, but who does not just slam that switch to max when heat or cold or just maximum breeze, is asked for?

[RoamingKat]

I looked at doing that too. But, once I had it out...I could see what people were saying....it is encased in plastic. I kept the old one. I am going to carefully crack into it and see if I can clean/fix it. I know I can’t break it, it is already broken.