Blower motor fan not working.

[EvanH]

So I have a 90 base 2.2L Beretta I bought recently, I cannot for the life of me figure out how to get the blower to blow at all. The fuse used to pop. I have replaced the blower motor, resistor, resistor plug with about 1 1/2 feet of wire soldered in, looked through the harness in the engine bay (which looked good) Then I went into the cabin where all the switches are found a melted wire that goes to the switch that controls what area it blows, soldered in a new wire all the way up where it melted, (I did bypass a plug but did not seem to be any more than a plug) and the only progress I’ve made after all of that was the Fuse stopped blowing immediately.

Please if someone knows a bit more and can help I would very greatly appreciate it.

[Rettax3]

Hi EvanH, welcome to the site.
Pics might help, particularly of the back of the switch you soldered the fresh wire into, but you've tackled the components already, aside from the relay and the in-dash switch itself... Did you find any components that were definitely bad?

I think you are going to have to find the ground-short that caused the melted wiring. From the little I know from this side of the keyboard, I think it probably toasted the switch in the panel itself with the repeated shorting. I suspect the switch is no longer delivering current, and that may be why it is not popping the fuse anymore. Definitely check for clean signal through the harness from point-to-point to see if you have any open lines, and check each for ground to find that short.

One thing that may help, I would suggest making (or buying, I suppose) a long-reach probe-wire set for your Ohm-meter (or multi-meter). My old Fluke has a regular set of test-probes and an extra Positive probe with a secondary wire-lead attached at the end of the probe that more than doubles the probe length. I have found this invaluable for a great many projects, and you should be able to hook to the relay-pack or the Resistor plug under the hood on one end, and to the dashboard HVAC control harness-connector on the other end. It is kind of a pain to run through each wire, but there honestly aren't that many of them and you can definitively find your answer...

I don't recall on our '90 Rettas if they use a fusible-link for the blower's full-power selection, but I kind of think they do... IIRC they run five wires into the relay, two are power IN and the common is power OUT, the side-of-dash fuse-block runs a 20-Amp fuse to power all of the lesser-speeds through the respective Resistor circuits, and a fusible-link under the hood supplies power for the full-power mode tripped on the relay's alternate (non-common) pole... But don't hold me to that, I don't have a schematic in front of me and I'm going off of 'could be this car and this year' memory... I can dig into it for sure if you don't have access to a wiring schematic, but I think you still have to run continuity tests on the wires...

Good luck, keep us posted!