Blown ignition fuse

Tiny
JSNMCGHEE
  • MEMBER
  • 1994 PONTIAC GRAND AM
  • 6 CYL
  • FWD
  • AUTOMATIC
Why would the ignition fuse on a 1994 Pontiac Grandam blow when you put the car into drive?
I have changed the fuse it blows every time.
Do you
have the same problem?
Yes
No
Saturday, July 30th, 2011 AT 8:56 PM

5 Replies

Tiny
JDL
  • EXPERT
How long since a tune-up? Any applicable mil codes? You can check those yourself.

Are you saying it idles just fine, in park or neutral, doesn't blow the fuse? Could be electrical wiring circuit that shorts? Don't know why it wouldn't short in park or neutral? I'd have to unplug everything on that fuse circuit, one at a time.
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Saturday, July 30th, 2011 AT 9:10 PM
Tiny
JSNMCGHEE
  • MEMBER
Yes it idles just fine in park, nuetral and in reverse, but a soon as you put the car in drive it blows the ignition fuse.
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Saturday, July 30th, 2011 AT 9:46 PM
Tiny
JDL
  • EXPERT
I'd have to separate the circuits that the fuse controls. Then I would use a jumper wire with inline fuse, see if I could get an individual circuit to blow the individual fuse. Then I would know which circuit the problem was on. Not a conclusive test.

Circuits controlled by that one fuse, crank sensor--cam sensor--primary voltage to ignition module--- computer. You can check wiring and connectors, see if anything looks like it has been getting hot?
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Sunday, July 31st, 2011 AT 4:19 PM
Tiny
JDL
  • EXPERT
Were there any applicable codes. You can check codes yourself. At the data link connector, you use a jumper wire between terminals A & B. Turn the key just till the dash lites come on, no further, no crank. Then the mil starts flashing, you count the flashes to get the codes. Your looking for two digit codes, the first code would be code 12, one flash, a slight pause then two quick flashes. The code will repeat three times, then move on to the next code, if there are any.
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Monday, August 1st, 2011 AT 3:18 PM
Tiny
JDL
  • EXPERT
I forgot this below, just shows location of A & B terminals.
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Monday, August 1st, 2011 AT 3:19 PM

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