I have a 1988 E350, 5.8L, No AC, front heat only (no rear unit).

The blower motor stopped working some time ago. I removed the old blower motor and hot-wired it to the battery - and it would not spin up. I removed the old blower motor and replaced it with a new one but I still can't get the blower motor to spin up.

I tested the NEW blower motor just to make sure I didn't get a defective one - and it works fine when hot-wired to the battery. I checked the leads to the HI/LOW fan switch on the dash with the ignition on/engine on and noticed that NONE of the leads to the switch had 12V! I have checked all the fuses in the fuse box with my ohm meter and all check out OK. I'm not sure what to check next....any ideas would be very much apprecaited. Thanks!!

 

Sounds like maybe your blower motor resistor pack is fried. Try pulling it out (should be mounted into the housing right next to the blower motor) and check to see if any of the wire-wound resistors are touching each other or are disconnected from the connector, etc. The way the circuit goes is like this: there should be a brown/orange wire running to your blower moter. With the ignition on, that wire should have +12V on it. If it doesn't then your fuse is blown or that wire is bad. Then there should be an orange/black wire coming out the blower motor. That wire splits to two places. It goes to the HIGH position on your fan speed switch and it also goes into the blower motor resistor pack. Then there are three wires that come out of the resistor pack and those go to the other fan switch positions - medium, low, etc. Finally there is a black wire that runs into the fan speed switch and that is your common ground wire. Check for continuety (ohm meter should read 0 ohms) between the vehicle frame and that black wire because if there isn't ground on that wire then you aren't going to get any fan. The fan switch connects the black ground wire to one of the other four (+) wires that were mentioned earlier, thus completing the circuit. Hopefully that all made sense. I tried to keep it as simple as possible.

Lloyd

 

WOW..that's for your thorough reply! I passed a Ford dealer today and picked up a new resistor pack as it was only $15 and figured what the heck the one in there is 15 years old. I installed it but still no good.

SO...just on a hunch - I put a hot lead directly from the battery to the orange lead on the blower motor and then put the ignition on...and presto - instant fan and the Hi/Low switch on the dash works just fine. SO...I'm thinking of just putting a lead from the battery to the fan with a 30AMP in-line fuse and calling it a job done.

 

OK...Initial excitement over. Yes - when hot wired to the battery the fan and high/low switch DO work - but the fan will NOT shut off completely. SO...for the immediate future - I don't mind opening the hood and popping in the 30AMP fuse into my hard wiring to engage the circuit so that I can have heat (it's getting cold up here in the NE).

More long-term...I surmize the following; the selector switch (located under the temp selector on dash) must be defective. My dad (whome I share the van with) seems to remember having to jiggle the selector switch to engage the heat/defrost/vent fuctions. Also... the selector switch is in charge of providing power to the blower motor. Even if the hi/low switch is set to high the blower motor will NOT spin if the selector switch is set to "Off". Once you move the selector switch to "Vent" or "Heat" or "Defrost" - then the blower will spin up at whatever speed is selcted on the high/low switch. Does this make sense? Is my thinking correct? Thanks SO much for your reply....it's very much appreciated.

 

Here's how it should work:

When the vent/heater/defrost switch is set to 'off', the fan should not turn at all, reguardless of how it is set (low, medium, high).

When you move the selector to heat or vent or whatever, then the fan should kick on at the speed set by the fan speed switch.

There is no 'off' position on the fan speed selector switch itself. The very bottom setting is 'low' and the very top is 'high' and however many more settings you have inbetween those.

So, if I read your post correctly, it sounds like everything is working properly now to me? I'm confused about what you meant when you say that the fan wont shut off completely though. When you flip the heat/vent/defrost switch to 'off', does the fan stop? That should kill the circuit (yes I forgot to mention about that switch in my previous post). If the fan just keeps going, then it is that 'off' switch on the vent/defrost controls that is bad. As long as all your fan speeds are working on the various switch positions of the fan speed selector switch, then there is nothing wrong with it. That's all that switch does (remember, there is no 'off' position to this switch). Now, if you shut your van off and leave the setting on 'vent' and the fan speed on 'high', then I can see where your fan would keep running. Perhaps this is the problem you were meaning? The reason for that is because you ran your blower motor straight to the battery and its not going through your fuse box any more. Normally, that line would only have power when the ignition was in the 'run' position. However, even with the key out of the ignition, the fan should still stop if you put the vent/defrost control to 'off'. If it doesn't, then that 'off' switch is bad. If you want your fan to die when you turn the key off even if you leave it on vent, then you'll have to run that new wire that is currently going to your battery to the fuse box instead. Just grab a multimeter and look for a nice empty spot where it looks like a fuse should go, yet there isn't one. Ground one side of your multimeter (or test light) and stick the other lead up in there until you find a spot that has 12V only when the key in the ignition is on. Once you find a spot, run your wire there. If there isn't an empty spot, you can also wrap your wire onto one side of an existing fuse. Just make sure you have a fuse that is only on when the ignition is on. You know, something like wipers. Keep that inline 30A fuse that you have on the wire just to be safe since you will then be running two things from one spot on the fuse box. If the fuse you connect your wire to in the fuse box pops when the blower kicks on, then you have to move the wire to the other side of the fuse. That way you're not going through that fuse, just borrowing the power coming into it. Best of luck. Hope you get everything going.

Lloyd