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Jared D
Jared D, ASE Certified Technician
Category: Pontiac
Satisfied Customers: 1441
Experience:  Shop Supervisor at County Fleet
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A/c bfc fuse keeps blowing so I get crank but no start, I

Customer Question

a/c bfc fuse keeps blowing so I get crank but no start
JA: Tell me a bit more about what's going on so he can help you best.
Customer: I need diagrams to check wiring to a/c compressor and also need to know how many ohms it should be if therte is not a short
JA: Are you hoping to fix this yourself?
Customer: im a mechanic and work for an aamco transmissions
JA: Is there anything else the Pontiac Mechanic should be aware of about your Pontiac?
Customer: nope just that im getting no injector pulse with the a/c bfc fuse blown, once replaced works fine but the fuse blows again and just come back to the same issue so I need to test the wiring going to the a/c clutch coil wiring
JA: I'm sending you to a secure page on JustAnswer so you can place the $5 fully refundable deposit now. While you're filling out that form, I'll tell the Pontiac Mechanic about your situation and connect you two.
Submitted: 10 months ago.
Category: Pontiac
Expert:  Jared D replied 10 months ago.


What year, model, and engine size do you have?

Customer: replied 10 months ago.
2003 Pontiac Grand Am 3.4 L
Expert:  Jared D replied 10 months ago.

On that model it definitely sounds like a shorted AC clutch coil. Yo have a multi-meter I assume?

You should check resistance across the connector of the clutch coil. It should be open or OL on your meter.

Expert:  Jared D replied 10 months ago.

If it's not, let me know what reading you get.

Customer: replied 10 months ago.
Where do I test the wire on the other side from the AC compressor clutch coil
Customer: replied 10 months ago.
what should be the reading my doing ohms or volts
Expert:  Jared D replied 10 months ago.

Ohms, test from pin A to B on the compressor connector.

Customer: replied 10 months ago.
Expert:  Jared D replied 10 months ago.

This diagram is the pigtail side, the compressor side matches it, across the two pins you should see OL. If you see 1, or any reading really, that means the clutch is shorted on.

The easier way to test it would be to unplug the compressor clutch and see if the fuse still blows.

Customer: replied 10 months ago.
If it doesn't it should be the compressor clutch coil right if it does blow again then what
Expert:  Jared D replied 10 months ago.

If it doesn't blow, then the clutch is the problem. If it does blow then you will need to check for resistance (ohms) from ground to pin B on the pigtail side. If you get anything other than OL or more than about 20 ohms of resistance then that wire is shorted to ground (rubbed through) somewhere between the clutch and the relay.

Expert:  Jared D replied 10 months ago.

Let me know how it turns out.

Please don't forget to rate.

Expert:  Jared D replied 9 months ago.

I just wanted to check and see whether you needed any additional help on this one.

Please don't forget to rate if I have been of some assistance.