Heater core replacement - now fan is screwed

[terprugr]

Replaced my heater core. Everything went fine, but now the fan only works on high and my alternator just can't take it. Which is another issue because I have a 110 amp alternator. Every bronco I ever owned (this is my third) has had electrical problems though.

Pulled the blower to see if something was stuck in there, but it is the same even with the blower just sitting on the fender. I don't know what I could have done.

 

[Broncobill78]

We need more info Chief. Was everything cool *before* you yanked it all to replace the core ? I can appreciate the sentiment, I've had a buttload of Bronco's and every damn one of them has had one sort of problem or another, but then again I've never had the coin to buy one NEW and more often than not I just wind up buying someone *else's* problems since I'm not one of those guys who shells out $10K for a 15yr old truck. It's going on a dozen years since Ford even BUILT aBronco so the sad fact here is that most of the ones up for sale are being sold for a *reason*.

Electrics are a stone cold bitch, no two ways around it. They're time consuming and just a big hassle in general. They sideline a lot of otherwise solid trucks and get a lot of trucks sold for cheap. Get yourself a factory manual & follow the troubleshooting guide, that's what a Dealer Tech will do.

 

[terprugr]

[Everything worked fine before it started leaking all over the place. That's what I don't get. I guess I can't avoid the fact that I am gonna have to break out the wiring diagram. Who am I kidding, that things gonna stay like that for a while. At least until I pull the engine for rebuild. Thanks for the assist though.

 

[miesk5]

yo

Ck the Blower Motor Resistor

Have some Links on it in my Bronco site

 

[terprugr]

That's probably it. Thanks. Didn't think of it. Why is that thing there? It makes no sense!

 

[oilhorse]

That's probably it. Thanks. Didn't think of it. Why is that thing there? It makes no sense!

the blower motor resistor controls the four fan speeds. IF you lost all but the highest speed then the thermal limiter (fuse) on the resistor grid has probably melted.. This limiter is a little metal device in the main electrical line and is there to keep the resistor block from getting too hot and starting a fire.. something that can happen IF the the blower motor takes a crap and no air is flowing over the resistors! The little limiter can be replaced ( cut out old one solder in new one in the EXACT way the old one was mounted) they cost about 2.00 at radio shack vs installing a new resistor assy which is about 20.00!