Inline fuse for A C blower fails after30 minutes or so.
The inline fuse for the air conditioning blower fails after driving a while. It is extra hot when feeling the fuse holder almost from start up and will melt the plastic fuse holder before it fails. Blower seems to have good speed and no unusual noise during operation. Anyone had this problem and solved it? I noticed a capacitator in the motor circuit - could it be faulty? The motor runs on low and medium with no problems - it seems the speeds run through the resistor are protected by a 30 amp agc fuse in the fuse panel below the gauge cluster and the inline fuse under the hood provides power for high speed only. Any ideas or solutions you have will be welcomed, and thank you in advance.
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Re: Inline fuse for A C blower fails after30 minutes or so.
What amp fuse are you using in the in-line fuse holder?? This fuse should be a 30 amp.
Larry -
Re: Inline fuse for A C blower fails after30 minutes or so.
Larry , the fuse is an AGC 30. The fuse holder becomes hot long before the fuse pops. The fuse in the cabin is also an AGC 30 as per the AIM instructs when AC is installed and has never exhibited any heating.Comment
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Re: Inline fuse for A C blower fails after30 minutes or so.
John
If the fuse does not make good, clean and solid contact within the fuse holder, the metal ends of the fuse will heat to the point of melting the fuse holder. The spring inside the fuse holder that presses against the fuse when the holder is closed has to be strong enough to make solid contact. It should take some effort to close and latch the fuse holder. Be sure you are using a quality fuse holder.
It is possible for the fan at high speed to draw right up to 30a. It is difficult, but not impossible to lubricate where the fan rotates in its housing. I have done it on vehicles other than Corvettes, but I am not sure how accessible the fan motor is on a C2. I suspect I know the answer (not very) but lest I run afoul of St Michael I will leave that to others.
As an easier route, if you have or can borrow a clamp-on ammeter, you can measure the current draw on that wire and see if the issue is a poor quality fuse, fuse holder or if the current draw is excessive. Those of us who love the opportunity to buy a new tool will follow the last path.TerryComment
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Re: Inline fuse for A C blower fails after30 minutes or so.
John
If your AC blower motor is operated ONLY at low/medium speeds, does this blower high speed in-line fuse get hot anyway?
If your AC is switched off, does this blower high speed in-line fuse get hot anyway?
DaveJudging Chairman Mid-Way USA (Kansas) ChapterComment
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Re: Inline fuse for A C blower fails after30 minutes or so.
Dave, when operated at low or medium speed the inline fuse does not get hot. When AC is switched off the fuse holder does not get hot. Terry, I am working on testing the current draw as you suggested. Will report the findings later as I have to be away for the afternoon. Larry, the expansion valve replacement cured the pressure problems and now have cool air at the outlet. Still not sure about the Schrader valve "by-pass"in the STV and as you suggested, that seems like it would be robbing capacity from the compressor. PM me with a convenient time to call you this evening so I can bring you up to date on pressure readings and get your thoughts.Comment
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Re: Inline fuse for A C blower fails after30 minutes or so.
John
Have you checked the AC Relay for operation? Link below to CF, with several wiring diagrams.
Dave
https://www.corvetteforum.com/forums...in-66-a-c.htmlACRelay_Resistor67.jpgJudging Chairman Mid-Way USA (Kansas) ChapterComment
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Re: Inline fuse for A C blower fails after30 minutes or so.
Cannot determine amp draw of AC fan motor yet. No DC amp meter in my stash of tools to measure that small amount of current. Will continue to look for one to borrow and post the results. BUT since the in line fuse holder was toasted beyond use I removed it and inserted an ATO fuse holder and a 40 amp fuse (blade type fuse) with positive connections and the blower ran for 1 1/2 hours on high with no heat at the fuse holder so Terry gets the gold star for figuring out the problems. I am pretty sure the inline fuse holder with the spring contact was the spot with all of the resistance and heat. hated to cut into a new "LL" harness to splice a modern component but had no choice and unless you really look hard the fuse is up and under the right front fender and out of sight. Will run the system with a 30 amp fuse next - picked up one this evening and let you all know the results but am confidant that all will be well. Thanks for all of the help and suggestions pointing in the right direction.Comment
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Re: Inline fuse for A C blower fails after30 minutes or so.
John
No gold star necessary. Happy to put my 48 years of electric utility work to good use, finally. Even if my experience there is with voltage about 1000 times that of our cars. The basic principles still apply. Excellent solution by the way. Two thumbs up to you.TerryComment
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Re: Inline fuse for A C blower fails after30 minutes or so.
John
40 amp fuse when 30 amp is specified? Fuses are supposed to fail - supposed to protect your circuit. Good idea to replace that damaged fuse holder, but that fuse holder got damaged for some reason. 40 amp fuse may just be masking real issue.
DaveJudging Chairman Mid-Way USA (Kansas) ChapterComment
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Re: Inline fuse for A C blower fails after30 minutes or so.
John,
I would remove the 40 amp fuse and replace it with a 30 amp ATC fuse to protect your wiring harness from burning up. If the original inline fuse holder was made in China ( junk ) I would replace it with a Buse fuse holder as they made them for GM for many years.
MikeComment
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Re: Inline fuse for A C blower fails after30 minutes or so.
ATO 30 is in place now and will use the car this weekend. Will let you all know the results. Circuit is now protected by specified fuse.Comment
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