jft69z Posted July 13, 2021 Share Posted July 13, 2021 Just now, Dtret said: O shut up. Eh, .... maybe she's right, lol Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 13, 2021 Share Posted July 13, 2021 Just now, jft69z said: Eh, .... maybe she's right, lol She’s definitely right. My mix of sarcastic humor usually wins out. I have to be careful because some don’t get it. Lol. Quote Link to comment Share on other sites More sharing options...
jft69z Posted July 13, 2021 Share Posted July 13, 2021 7 minutes ago, Dtret said: O shut up. If I had feelings, maybe they would have been hurt by your unkind words 🤣 Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 13, 2021 Share Posted July 13, 2021 9 minutes ago, jft69z said: If I had feelings, maybe they would have been hurt by your unkind words 🤣 Ok tinman. I know ‘heart’ but it still applies. 1 Quote Link to comment Share on other sites More sharing options...
Rob Peters Posted July 13, 2021 Share Posted July 13, 2021 2 hours ago, jft69z said: High resistance causes heat. Could also be a poor connection at the plug, and also a bad blower motor that's drawing excess current. Again, measuring actual current is the best place to start troubleshooting. Then you know what you're dealing with. Joe is right. High resistance causes heat. If the connections in the plug are compromised or if the blades on the switch are not clean, or if the metal pieces connected to the wires inside the plug do not have enough tension to compress onto the switch blades (blades meaning the pieces of metal the plug connectors slip over) it will cause high resistance and the heat to melt the plastic on the plug. I have never seen the plug that attaches to the blower melt like that so it may just be a design flaw in the plug at the switch. Incompatibility of metals in the switch blades and plug can cause early corrosion, thus creating the high resistance,. rob 1 Quote Link to comment Share on other sites More sharing options...
Brew Posted July 14, 2021 Author Share Posted July 14, 2021 This is second plug like that to melt. the first was on the original ac controller. I got a refurbished one & replaced both the plug & the blower motor. So I’m leaning towards resistor. I will try out the testing suggested first. To be continued... Quote Link to comment Share on other sites More sharing options...
jft69z Posted July 14, 2021 Share Posted July 14, 2021 7 hours ago, Rob Peters said: If the connections in the plug are compromised or if the blades on the switch are not clean, or if the metal pieces connected to the wires inside the plug do not have enough tension to compress onto the switch blades (blades meaning the pieces of metal the plug connectors slip over) it will cause high resistance and the heat to melt the plastic on the plug. I have never seen the plug that attaches to the blower melt like that so it may just be a design flaw in the plug at the switch. Incompatibility of metals in the switch blades and plug can cause early corrosion, thus creating the high resistance,. rob To show what can happen, this is a fairly common problem with C6 corvette cooling fans. Doesn't happen to all, and the common cause appears to be poor contact connection tension/resistance as Rob listed. That, plus the high current loads, (maybe close to the connector design limit) will cause failure. There are actually specs and tools to measure contact tension. I've run into it occasionally on newer cars, where everything is electronic. Using a small pic, you can usually bend the inner contact to get some of the tension in the connection back. Have around a 2000+ GM with intermittent ABS troubles? Scan & scope the wheel speed sensors on a test drive, then check/tweak the contact connections at the wheel bearing assemblies & harness. May save you a lot of money before replacing the wheel bearing assembly that was actually good. (pictures courtesy of the corvette forum, other people that had a bad day) Quote Link to comment Share on other sites More sharing options...
Canuck Posted July 14, 2021 Share Posted July 14, 2021 That same connector is melted on my 71. I have unplugged it for now but I will need to look into the issue at some point. Quote Link to comment Share on other sites More sharing options...
alex's72fgmc Posted July 26, 2021 Share Posted July 26, 2021 An amp meter I would not recommend but an amp clamp that is hooked up to a scope would be best. Odds are the blower motor is going bad causing a high amp draw to spin it. As for the blower motor resistor use a ohm meter and check resistance on each leg of the circuits. Low speed should have the most resistance and high speed should have the lowest. As for the melting of the connector that is a result of high current (amps) flow. And before anyone wishes to flame me yes resistance can melt stuff as well but with a new connector and resistor makes it doubtful. The blower motors on most cars are on a 30 amp circuit but typically see no more than 20 amps when blower is running but spikes to 28 +amps on start up on high speed. 1 Quote Link to comment Share on other sites More sharing options...
NicAtNight2262 Posted August 10, 2021 Share Posted August 10, 2021 Brew. I hope you do not mind me asking but I’m having the same issue. Where did you find the connector? Is there a part number? Quote Link to comment Share on other sites More sharing options...
Brew Posted August 10, 2021 Author Share Posted August 10, 2021 1 hour ago, NicAtNight2262 said: Brew. I hope you do not mind me asking but I’m having the same issue. Where did you find the connector? Is there a part number? I found it on another Monte. but I am going to replace this one with individual, insulated connectors Quote Link to comment Share on other sites More sharing options...
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