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Now that the weather is getting colder, heat would be nice,lol
Orginal problem is no high speed fan. I've replaced the blower motor, blower resister and harness. I have 14 volts to blower motor itself. It works but not at any real speed. I've swapped relays around and still no change. I feel like I'm missing something? any ideas of where I go from here?
The dash mounted switches and connectors have been known failures---they melt and loose contact. Here's an example:
If you replace the switch replace the wiring harness connector too---use top quality parts as you don't want this failing again due cheap parts. One word of advice is pay attention to the chassis wiring locations on the switch connector---those in the aftermarket and even Motorcraft don't follow the factory wiring color scheme. Replace one wire at a time according to the location of each wire on the connector.
Ford uses the blower switch to select which point in the blower resister array to ground (there is 12v fed through the fan motor first then onto the resistor array) So, while you are in that area use a multimeter with the plug pulled from the switch or better yet the battery disconnected, check the connector's ground socket for ANY resistance. It needs to look like a dead short for the motor to run at full speed.
Had the same issue myself until I replaced the switch.
Originally Posted by JWA
The dash mounted switches and connectors have been known failures---they melt and loose contact. Here's an example:
If you replace the switch replace the wiring harness connector too---use top quality parts as you don't want this failing again due cheap parts. One word of advice is pay attention to the chassis wiring locations on the switch connector---those in the aftermarket and even Motorcraft don't follow the factory wiring color scheme. Replace one wire at a time according to the location of each wire on the connector.
HTH
+1:
I replaced the four-blade switch & harness on my '94 E-150 with this and this, respectively. If your model has a five-blade switch, you'll want this and this, respectively.
Tags: HC319, EC70, HS300, EC192
Last edited by TimothyOnline; 11-17-2018 at 09:53 PM.
Reason: Specified parts used and added picture of failed harness.
Had the same issue myself until I replaced the switch.
I replaced the four-blade switch & harness on my '94 E-150 with this and this, respectively. If your model has a five-blade switch, you'll want this and this, respectively.
Tags: HC319, EC70, HS300, EC192
Great links---others will find that VERY useful---reps sent!
Having only owned '97 and later E-Series I've not seen the five blade switches or replacement connectors. NAPA's parts at great quality, a bit less than OEM/Motorcraft---those I've replaced haven't failed again in 8+ years.
11-14-2018, 11:57 AM
