mmccammon Posted August 11, 2019 Share Posted August 11, 2019 Having hard time finding this. the ac part referenced at local parts store pulls a substitute that’s too small. saw another option on eBay help! i replaced switch.. runs fine plugged into old melted connector but want to replace connector. ( why do these melt?... I have seen this mentioned in a few places) thanks mike Quote Link to comment Share on other sites More sharing options...
72Ragtop Posted January 16, 2020 Share Posted January 16, 2020 I've had this on most of my GM's w/ AC that have 4-speeds for the fan. Hard to nail down the specific issue which is the Fan or the switch itself. As the fan ages, it can be harder to get it turning, requiring more amps which can stress the wiring and the fan switch internal contacts. I've normally had the switch fail in the 3rd highest speed, (the one I seem to want to use the most!), while the lower two speeds continue to work. Also look for high heat build up at the "Max speed" in-line fuse and wiring that are in the engine bay...I've seen that get so hot that the factory in-line fuse holder "melts" slitely and makes max speed function intermittently. In 2007 during my MC Convertible build, I installed new fan, new switch AND 4 relays with it's own 10 ga. wire and Circuit Braker, so the fan load is no longer on the switch contacts. No law says you have to use that plastic connectour body...crimp and solder on a good female terminal and cover with heat shrink. Example: New aftermarket electronic cooling fans normally require a 30 or 40 Amp Circuit Braker....this is for the high amps normally required to get the turning....Amp requirements drop while the fan(s) are running....it is that first start-up that is "arcing" at the GM fan switch and slowly destroying the contacts and causing heat build-up. I'm installing a complete Vintage Air AC system as I write this, so I pulling the old system from 2007 and was "redlining" my custom wiring diagrams, so I was checking the site and saw your posting. The fotos I attached are of the "Relay System" I installed in 2007. 1 Quote Link to comment Share on other sites More sharing options...
72Ragtop Posted January 21, 2020 Share Posted January 21, 2020 I've tried to reply to what may have been a private E-mail about this subject, but with all things computer...the simple things, that I have done before will not work as "something" has been changed. I did get an E-mail from "somewhere" about it not going thru, but it was written in "un-understandable computer gibberish". (I have a flip-phone) I am now retired and no longer have the ability to print or scan. If any one wants a copy of my custom wiring diagram of this relay/heater control system, send a standard business-size SASE to: Dave Winters, 112 35th street SW, Loveland, Colo. 80537 Quote Link to comment Share on other sites More sharing options...
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