Vintage Mustang Forums banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Ride of the Month Challenge!

1 - 7 of 7 Posts

·
Registered
Joined
·
4,193 Posts
Discussion Starter #1
Stats: new Classic Auto Air "Perfect Fit" system.

Problem: When sitting still, everything is fine. The A/C blows steady and ice-cold. But when I accelerate, the strength of the blowing increases – almost as much as if I clicked the fan to the next highest speed. It seems to level back off once I reach cruising speed (at least I think it does). It may wait until I come to a stop – kinda hard to distinguish over the glasspacks! :p The problem this creates is if the unit is already on "high" it blows the heater fuse. (This type of system runs off the original heater wiring, and therefore uses a 14A fuse.) Not much of a warning either... It just surges from "High" to "Really High" and then shuts down before I can react. Apparently at the highest setting it's pulling a full 14 amps; but these surges push it over the limit.

Question: What the heck is causing this? :p I pulled out the fusebox and cleaned the fuse holders really well (per a suggestion from an earlier post); but it hasn't done the trick yet. Could it be a grounding issue?

If I keep the blower set no higher than "Medium" I'm okay. But sometimes I need that "High" setting, man! :: Any ideas what's causing these surges?
 

·
Registered
Joined
·
2,288 Posts
Hello.It could be a faulty voltage regulator.I think that I'd check with a volt meter while the A.C. is running with the motor at various R.P.M.s to see what it is actually getting,then back-track the problem to it's point of origin.Hope that helps. :)
 

·
Registered
Joined
·
3,102 Posts
Check with CAA about the actual full load current at the higher voltage available above idle. You may need to increase the wire size and fuse (or circuit breaker) feeding the heater/AC system. The wire feeding the heater fuse from behind the fuse block is also a limiting factor. A completely new wire from the ACC terminal of the IGN switch might be necessary. Not sure what to recommend about the heater fan switch as I am not familiar with the wiring and operation of the "perfect fit" system. Good Luck.
 

·
Registered
Joined
·
6,340 Posts
Does it blow harder when you rev it out of gear ?
I remember someone saying you might need to install a relay in your system and power the unit directly from the battery with a inline fuse in the circuit .
Id give the manufacturer a call and ask them . If it's happened before they will know exactly what your car is doing and how to fix it.
 

·
Registered
Joined
·
4,193 Posts
Discussion Starter #6
That's a good question, Lemondrop – I'll have to see tomorrow. I did already call CAA and ask why it kept blowing fuses; but at the time I hadn't noticed the blower surge (so they didn't factor it into their solution). They suspected it was a poor ground.

I've been using the courtesy light attaching screw under the metal dash. So I unhooked it and sanded down to bear metal. I know it's making good contact now.

Thanks for the input so far everybody! ;)
 

·
Registered
Joined
·
2,127 Posts
So, you have checked the ground end of the circuit....how about the 12 Volt supply? How about temporarily running a fused 10-gauge wire from the battery to that connection of your heater circuit you mentioned that is now supplying your A/C? Disconnect your heater and the dash heater supply wire and run the new A/C off of this 10 gauge fused wire off the battery and see how it acts. Just as a temporary test you could route it through a door window vent or something like that. John
 
1 - 7 of 7 Posts
Top