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#18 fuse in 91 mustang convertible blown

  • Thread starter Thread starter NFLjunkeez
  • Start date Start date Feb 16, 2013
N

NFLjunkeez

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Feb 16, 2013
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Feb 16, 2013
#1
  • Feb 16, 2013
  • #1
For some reason my #18 fuse keeps blowing. None of my dash gages work with exception for the odometer. As soon as I replace the fuse with the required 15 amp fuse it blows the minute I turn the igniton. I decided to place a higher amp fuse just to see what the thresh hold was and I got to a 30 amp without it blowing when I turned the ignition. However, the second i push on the gas it blows.

Any common faults I need to look at? Any ideas would help. Thanks
 

MikeH686

Mine is only two inches though.
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#2
  • Feb 16, 2013
  • #2
Find out what is on that circuit and start from there
 
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NFLjunkeez

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#3
  • Feb 16, 2013
  • #3
MikeH686 said:
Find out what is on that circuit and start from there
Click to expand...

Acording to my chilton book that circuit controls the Warning Indicator Lamps, Throttle Solenoid Positioner, Low Fuel Module, Dual Timer Buzzer, Tachometer, Engine Idle Track Relay, and Fluids Module Display
 

MikeH686

Mine is only two inches though.
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Feb 17, 2013
#4
  • Feb 17, 2013
  • #4
Well you say it blows when you step on the gas check the tps circuit usung a multi meter to make sure the wires are still good and that the sensor is still good
 

HISSIN50

"How long does it take to get help in here?
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#5
  • Feb 17, 2013
  • #5
Never install a higher-rated fuse.

Generally one would disconnect all items on the circuit and plug them back in till the fuse blows. Since you have a feeling it's TPS related, as noted by Mike, you could try starting off by disco'ing the TPS connector and see if the fuse remains intact. If so, look for a short in the TPS wiring.
 

MikeH686

Mine is only two inches though.
10 Year Member
Oct 11, 2011
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Feb 17, 2013
#6
  • Feb 17, 2013
  • #6
Reason i say tps is when he hits the gas its blows so maybe something shorted inside the sensor
 

HISSIN50

"How long does it take to get help in here?
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#7
  • Feb 17, 2013
  • #7
The TPS
MikeH686 said:
Reason i say tps is when he hits the gas its blows so maybe something shorted inside the sensor
Click to expand...
In case my post was opaque, I agree.
Large fuse aside, it held ok [albeit with a 30 amper] till he hit the gas. The TPS sounds like the circuit to start with.
 

jrichker

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Feb 18, 2013
#8
  • Feb 18, 2013
  • #8
Just to keep you from chasing a non existent rabbit...

Neither the TPS (throttle position sensor) nor the IAC/IAB (idle air control solenoid) aka Throttle Solenoid Positioner draw power frmo fuse #18 on the fuse panel. The TPS sensor draws 5 volts from the computer regulated power inside the computer. The IAC/IAB draws power from the same circuit as the computer, the EEC relay circuit.


Diagram courtesy of Tmoss & Stang&2birds



As shown in the diagram, fuse #18 branches off to provide power for other things.


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif

93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif
 

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