Aug 252016

1986 Ford F-350Can’t get power past fuel pump relay?


Looking at the wiring diagram for the Fuel Pump Relay. Black wire should be grounded. The Red/Yellow wire should be battery positive when activated and will connect power from the Yellow wire and flow through the Pink/Black wire to feed the fuel pump. If you are not seeing battery positive on the yellow wire, check the Inertia Switch.

fuel pump relay wiring fiagram 1986 Ford F-350

Two electric pumps are used on fuel injected models; a low pressure boost pump mounted in the fuel tank and a high pressure pump mounted on the vehicle frame. Some models equipped with the 8-460 (7.5L) carbureted engines use a single low pressure pump mounted in the fuel tank.

On injected models the low pressure pump is used to provide pressurized fuel to the inlet of the high pressure pump and helps prevent noise and heating problems. The externally mounted high pressure pump is capable of supplying 15.9 gallons of fuel an hour. System pressure is controlled by a pressure regulator mounted on the engine.

With internal fuel tank mounted pumps tank removal is required when servicing the pump. Frame mounted models can be accessed from under the vehicle. Prior to servicing release system pressure (see Fuel Supply Manifold details). Disconnect the negative battery cable prior to pump removal.

Aug 242016

2003 Ford WindstarEngine lopes and rpm drops down to 3-400, warning lights sometimes flash. If I turn off A/C the engine will go to approx. 700 rpm and run fine.
As soon as I turn on A/C, it does it again. Runs great on highway.


I see a couple of different possibilities why the AC Lowers Engine RPM.

  1. Could be an engine misfire. This means the engine isn’t running quite right on all cylinders. And when the added stress of running the Air Conditioning comes into play it causes the engines rpms to drop. This would also explain the check engine light flashing. Have the check engine light trouble codes pulled and post the codes below for further information.
  2. The Air Conditioning system have been overcharged and the engine is having trouble turning the compressor.
Aug 232016

1990 Ford RangerWhere is the oil pressure switch, I cannot find it on my 1990 Ford Ranger 2.9L engine?


NOTE: Oil pressure senders are used for oil pressure gauges, whereas the oil pressure switches are used for vehicles equipped only with a low oil pressure warning lamp.

The oil pressure senders/switches are located as follows:

  • 2.3L engine — left, rear side of the engine, in the cylinder head
  • 2.9L and 4.0L engines — front left side of the engine, below the cylinder head in the engine block

Oil Pressure Switch Testing

1990 Ford Ranger oil pressure switch location diagram

  1. To test the oil pressure switch, open the hood and locate the switch.
  2. Disconnect the wire from the switch. Attach one end of a jumper wire to the terminal on the end of the wire, then touch the other end of the jumper wire to a good engine ground (any bare metal engine surface). Have an assistant observe the instrument gauge cluster while you do this and tell you if the low oil warning lamp illuminates or not; the low oil warning lamp should illuminate.
    1. If the lamp does not illuminate, skip to Step 3.
    2. If the lamp does illuminate, replace the switch with a new one.
  3. Before jumping to any bad conclusions, try a different area for grounding the jumper wire on the engine. If the lamp still does not illuminate, touch the jumper wire end to the negative (-) battery post.
    1. If the lamp illuminates, the problem lies with the engine not being properly grounded.
    2. If the lamp does not illuminate, skip to Step 4.
  4. Connect the original wire to the oil pressure switch. While sitting in the vehicle, turn the ignition switch to the  ON position without actually starting the engine. Observe the other lights on the instrument cluster.
    1. If all of the other lights illuminate when turning the ignition switch  ON, the oil pressure switch is defective and must be replaced.
    2. If none of the other lights illuminate, there is a problem with power supply to the instrument cluster and gauges.

Oil Pressure Switch Removal

1.Disconnect the negative battery cable.
2.Disconnect the wiring at the sender/switch.
3.Remove the oil pressure sender/switch from the engine.
To install:

4.Coat the threads with electrically conductive sealer and thread the unit into place. Tighten the sender/switch to 10–18 ft. lbs. (13–24 Nm).
5.Attach the wiring to the sender/switch and connect the negative battery cable.

Aug 192016



Start with pulling any check engine light codes and then post them below in the comments for further information. Could be a failing engine sensor or ignition component accompanied with a sticking IAC valve. These will cause the engine to idle rough.

Aug 172016

2004 Ford EscapeMy battery light was coming on. My alternator went bad alright so I replaced it. I bought a new battery. When I was changing it I messed up the voltage regulator and didn’t know it. Eventually I took it and had it rebuilt, the alternator that is and put a new plug on it. It still wouldn’t run right so I took the battery to get checked because I jumped it quite a few times when alternator was still messed up and now the battery is bad. These model cars have chronic electrical issues and I noticed that my ignition is a little loose. When I pull the key out it makes noise like the keys in it. I know once I get this new battery it’s still not going to charge probably. I took alternator off myself under the computer and vacuum hoses and pulled it out the top what you’re not supposed to do but it worked. I’m wondering if I damaged a wire in the wiring harness. How do I check that? I know how to do the voltmeter but where my harness goes into the ECM, can that be taken apart to test? This is the real question I need, can my ignition switch or coil packs keep my charging system from charging? Because I’m almost positive I need new coil packs because of the missing and how crappy the car runs. And could the battery not charging make it miss and run crappie like it would if the coil packs are out? I can’t afford to take it to the mechanic and I have to get it running. Sorry this isn’t written better. If you can make sense of it, if not just say so and I will revise and write better thank you.


  1. Can my ignition switch or coil packs keep my charging system from charging?

No. The ignition switch nor the coil pack have anything to do with the charging system.

2. Could the battery not charging make it miss and run crappie like it would if the coil packs are out?

Yes. A weak battery and a failed alternator can cause the engine to function improperly due to a lack of proper voltage to the PCM.

Make sure to check your fuses after replacing the battery and alternator.

2004 Ford Escape Charging System Wiring Diagram

Aug 112016

2000 Ford RangerWhen I accelerate to driving speed and take my foot off the accelerator the engine will not idle down. And when the engine does idle down it smells like gas.


In most cases when an engine idles high it is caused by a vacuum leak. This would also cause the engine to add  more fuel. The engine adds more fuel to try and compensate for the extra air it is taking in. Most common place for a vacuum leak is on the PCV hose. You may need to remove the left front inner fenderwell splash shield to gain access.

PCV 2000 Ford Ranger

Engine Emission Control

CAUTION: Do not remove any part of the engine emission control system. Operating the engine without the engine emission control system intact will reduce fuel economy and engine ventilation. This will weaken engine performance and shorten engine life.

The engine emission control system consists of the:
•positive crankcase ventilation (PCV) system.
•exhaust gas recirculation (EGR) system (2.3L and 4.0L engines only).

Exhaust Gas Recirculation

The EGR system returns a small amount of exhaust gas into the intake manifold. This reduces the overall combustion temperature. Cooler combustion temperatures provide a significant reduction of the oxides of nitrogen (NOx) in the exhaust emissions.

2.3L Engine

The 2.3L engine incorporates a stepper motor-controlled EGR valve which receives its signal from the PCM. Engine coolant is used to cool the EGR valve. The EGR valve and stepper motor are serviced as an assembly.

4.0L Engine

The powertrain control module (PCM) controls the EGR vacuum regulator solenoid. The EGR vacuum regulator solenoid controls the vacuum to the EGR valve. When the EGR valve opens, exhaust gas flows to the intake manifold to be returned to the combustion cycle. The differential pressure feedback EGR system monitors the flow and returns a signal to the powertrain control module (PCM).

The amount of recirculated exhaust gas depends upon:
•engine rpm.
•intake manifold vacuum.
•exhaust backpressure.
•engine coolant temperature.
•throttle position.

Exhaust Emission Control System

The vehicle emission control information (VECI) decal is located on the upper radiator support and shows:
•components of the emission control system.
•the correct vacuum hose routing.
•the color stripe of the vacuum hoses.

Positive Crankcase Ventilation (PCV) System

The PCV system uses intake manifold vacuum to ventilate blow-by fumes from the crankcase and return the fumes to the intake manifold for combustion. The 2.3L engine does this through a water-heated fitting. The PCV valve varies the amount of blow-by gasses returned to the intake manifold based on available engine vacuum. The PCV valve also prevents the entry of combustion backfiring into the crankcase.


Aug 102016

1993 Ford Explorer SportDoes it need shims for starter ? If so , what size shim ??


NO. There are no shims needed or used during a starter replacement on a 1993 ford explorer sport.

Starter Replacement 1993 Ford Explorer


1.Disconnect the negative battery cable.
2.Raise the front of the vehicle and install jack stands beneath the frame. Firmly apply the parking brake and place blocks in back of the rear wheels. Disconnect all wires connected to the starter, including this ground wire on the starter mounting bolt stud
3.Tag and disconnect the wiring harness at the starter.
When detaching the hard shell connector at the S-terminal, grasp the plastic shell to pull it off. Do not pull on the wire itself. Ensure to pull the connector straight off to prevent damage to the connector and S-terminal. If any part of the connector is damaged, replace the damaged component.
Remove the starter motor (arrow) mounting bolts . . .
starter replacement
4.Remove the starter mounting bolts and remove the starter. . . . then remove the starter — be careful, the starter motor can be quite heavy

Starter Replacement 1993 Ford Explorer

To install:

5.Position the starter motor against the engine and install the mounting bolts. Tighten the mounting bolts to 15–19 ft. lbs. (21–27 Nm).
6.Install the starter solenoid connector by pushing it straight on. Ensure that the connector locks in position with a notable click.
Install the starter cable nut to the starter solenoid B-terminal. Tighten the nut to 80–123 inch lbs. (9–14 Nm).

7.Connect any remaining wiring to the starter motor.
8.Lower the front of the vehicle and remove the wheel blocks.
9.Connect the negative battery cable.

Aug 102016

2003 Ford TarusWhere are the fusible links located on this vehicle.


Fusible Links are generally located along the battery cables. The cables that connect between the battery and the alternator are widely used on many vehicles. When the links fail the entire section needs to be replaced. The 2003 Ford Taurus does not have any. Instead it utilizes a large 174 amp fuse that is located in the Battery Junction Box.

fusible links


Fusible Links – Power Distribution 2003 Ford Taurus


What is a Fusible Link?

A fusible link is a short piece of insulated low-voltage cable within an automotive wiring harness. It is there to protect the harness where a fuse is unsuitable. In an extreme current overload situation, the conductor within the link is melted while the excessive heat is contained within the link’s insulation.

Aug 082016

1997 Ford EscortI have a 1997 ford escort and was hearing a noise that the mechanic said was the spring or bearings inside one of the pulleys. I’m not sure which was the issue, the spring or bearings.  So I replaced the whole setup pulleys and tensioner. Before I could get to the carport I smelled hot melting rubber. After letting it cool down I could see smoke coming from the belt and it was hot. After getting it put back together, I started it and sounded good for couple minutes then the belt broke. Any idea what made it hot and break the belt?


Most likely reason would be a locked up pulley or accessory. The accessories being the power steering pump, air conditioning compressor or alternator. The Air conditioning compressor or alternator would be the most common. With the belt broke already I would check these accessories before installing a new serpentine belt.

Try to spin them by hand. If they are locked up, the issue is found. Some of the pulleys may sounds off if an internal bearing is going out. These may need to be replaced but unless really worn out would not cause the belt to break. Only a locked up pulley or accessory would cause the belt to break. What happens when the belt slides over the locked up accessory component, it creates friction/heat and burns the belt in two.

Belt Broke – 1997 Ford Escort Serpentine Belt Replacement


belt broke - serpentine belt routing diagram 1997 Ford Escort

Relieve the drive belt tension.

  • Use a (A) ratchet or breaker bar inserted in the square hole in the drive belt tensioner flange.
  • Rotate the (B) drive belt tensioner in a clockwise motion to release belt tension.
  • Remove the drive belt from the accessory drive belt routing pulley (6C348) and slip it off the remaining accessory pulleys.


  1. Position the drive belt over the accessory pulleys. Raise and support the vehicle, if necessary.
    • Use a (A) ratchet or breaker bar inserted in the square hole in the drive belt tensioner flange.
    • Rotate the (B) drive belt tensioner in a clockwise motion.
  2. Slip the drive belt under the accessory drive belt routing pulley and release the tool. Remove the tool from the drive belt tensioner.
  3. Ensure that the (A) drive belt V-grooves are correctly seated in the (B) accessory pulley V-grooves.

Serpentine belt pulley groove