electrical

[Bronco Fanatic]

I have a 1996 Ford Bronco Eddie Bauer 5.8l Windsor.

Last night I was driving down the road and my oil pressure gauge since the day i bought it was always reading high it jumped first twice to nothing then high and back and later driving home at 35mph and the speedometer dropped to zero and then jumped to 50 and then back to zero while my rpm's went to 2500 and styed there and in my pedal the power was gone and then when the speedo dropped in my speed range the trans would shift it seemed like it couldnt decide what gear it should be in and then it would be fine for a minute or two and it did this about 4 times. everything else in the truck was ok the lights stayed on and etc. Please help what could the problem be??

 

[miesk5]

yo,

Overview in 92-96; "The oil pressure system uses a switch and a fixed resistor; the resistor is attached to the engine wiring harness. A primary magnet, to which a shaft and pointer are attached, rotates to align this primary field, resulting in pointer position. The bobbin/coil assembly is pressed into a metal housing which has two holes for dial mounting. There are no adjustment calibrations or maintenance required for this gauge; Oil Pressure Sender - The oil pressure sender controls the magnetic oil pressure gauge's pointer position. The oil pressure sender (switch) closes under normal engine operating conditions. The oil pressure sender opens with the engine off and no oil pressure..." read moreSource: by Steve83

This shows how to UNDO this on vehicles originally built with the 6psi switch, up to ~1996.

Later vehicle have the resistor built into the gauge head, so the gauge would have to be swapped out for an older one to make this work.

Oil Pressure Sender

This is the NAPA number for the old-style oil pressure sender that is needed to convert a fake gauge into a real working one. The BWD number is S334. For V8 engines, it's also necessary to space it out from the block using common 1/4" plumbing: a 4" ****** & a 45� elbow. I6 engines don't need the spacer.

Then the 20-Ohm resistor that goes to the pressure gauge must have a jumper wire installed across it. The cluster shown is for a '94 Crown Vic, but the location of the resistor varies, and it's in the wiring harness for some applications. Don't mess with the 350-Ohm resistor for the ALT lamp, or any others. I used a Wh/R jumper wire to remind me that it's for the oil pressure circuit, which is Wh/R on most Fords. This process is the exact opposite of this TSB: READ MORE for more links and pics, etc.



4.9L I6 engines have plenty of room to simply install the larger sender. But on V8s, there's not enough room at the block for the sender, so a spacer is required, just like the factory used. But common plumbing pipes are cheaper (~$2) than the machined part Ford used (~$25) which is #15 in this diagram.

Afterward, a wire must be installed across the oil pressure resistor. I'm not sure where the '87-91 resistor is, so it may be necessary to overlay a wire onto the harness from the switch connector at the engine all the way to the instrument cluster. On '92-96, the resistor is on the instrument cluster film circuit. I normally make the jumper wire long enough to hang down below the cluster so it can be cut if a future owner chooses to convert back to the original switch & have an idiot-gauge again.

Sender Failure; "Corrosion or faulty electrical connections; If the oil pressure gauge is pegged low after the engine is running, or is pegged high after the engine is running, or if there is intermittent illumination of an oil pressure indicator light, the sender could be faulty. Related Components to Check; All appropriate electrical connections to and from the sender The oil pressure gauge or indicator light; Appropriate fuses (see Shop or Owner’s Manual for fuse layout)..." miesk5 Note; enter applicable info for year, etc.

Source: by MOTORCRAFT

Test & Installation Tips in a 90; "...My oil pressure gauge was reading on the "N" of the NORMAL range. After doing some research it seemed like it could be the oil pressure switch, also known as a sensor or sending unit. Disconnect the wire from the switch, ground it to the truck and turn the key on. If your gauge quickly moves to the left, the problem is most likely the switch. The switch on my 5.8 is located near the oil filter. It is in a difficult spot to work on so I advise that you go to NAPA and get an Oil Pressure Switch socket to do the job. The cost is about $7-$8, this will save you time and will help you reinstall the new switch. Make sure that it is in tight, I don't know about torque specs, I just put mine in quite snug. Hook the wire back on and start your engine. For me it was the cure. My oil pressure now reads over near the "M" on NORMAL..."

Source: by Canoeboy146

more info in my site @ http://www.broncolinks.com/index.php?index=949

GL!

 

[Bronco Fanatic]

Could the problem have been an overheated engine? i had a very small leak in my water pump and i went to look at it today and there was a bunch of antifreeze frozen on the side and then down the lower return hose.

 

[miesk5]

yo,

I'm sorry, I messed-up and when I was editing my reply I must have over-wrote a lot. When I edit a word for spelling for example, the screen jumps up or down about 8 lines and I could have replaced a lot with the edit.

Yes, check coolant level and find the cause of that leak; ck obvious places first such as hoses, radiator 9esp the sides where most radiators have plastic panels) and water pump/Weep Hole Underneath Pulley Shaft; It's a weep hole to let you know when the seal around the impeller fails. If it's leaking from there, you'll have to replace the water pump; thermostat housing

On the tranny, other than internal damage, This problem could be caused by a # of thangs;

bad vehicle speed sensor (VSS) (also called ABS,, DSS sensor) sensor on da 8.8 (rear differential)

connector/corroded wires inside connector; or cruddy/damaged tone ring in the 8.8 (Any slight dents, chips, etc., in either the exciter ring or VSS will create needle waver. Measure air gap between the VSS and exciter ring. It should be 0.38-0.51mm (0.015-0.020"). see TSB below)

bad wiring/shorts /connectors from VSS at firewall, at 4WABS Module and /or at PSOM and then onto the PCM and then to tranny

bad 4WABS Module - It is located below ws wiper fluid/coolant recovery tank. So, the connector can be corroded by leaking fluid

bad PSOM (Speedo)

Usually, it is the VSS sensor.

Is the Amber ABS Light on?

Is the PSOM needle jumpin' around wildly at times?

My 96's same symptoms (ABS light On and PSOM needle jumpin') were erratic until the 4WABS Module's microprocessors finally burnt-out. 4WABS Module, also called da ABS computer; 2 yard Modules were also bad; so I jumpered the Module out as Turbo Ghost

describes below.

To bypass the 4WABS module @it's harness's connector & feed the ABS signal directly to the PSOM,

Disconnect module (under coolant recovery /ws washer tank) & in connector

...jumper 14 (CKT 530, LG/Y) to 21 (CKT 519 (LG/BK) & 39 (CKT 491 (O/LB) to 22 (CKT 523, R/PK)...";

Source: by Turbo Ghost

http://img.photobucket.com/albums/v252/turboghost/ABSConnectorw-jumpers.jpg

Speed Input Signal Test @ PSOM in 93-96 Bronco; "...NOTE: Only wiring harness end of connector is to be probed. * Connect Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent to Pin 4 (speed in ) and Pin 5 (speed in -). * Does the voltage increase smoothly and continuously from 0 to approximately 3.5 volts as vehicle speed increases from 0 to 48 km/h (0 to 30 mph)? OR: If available, a frequency counter may be connected to Pin 4 (Speed in ) and Pin 5 (Speed in -). Does the displayed frequency of the signal increase smoothly and continuously from 0 to approximately 667 Hz at approximately 48 km/h (30 mph)? OR: * If neither a voltmeter nor frequency counter is available, vehicle speed control may be used as a good indicator. If it works normally, then the speedometer module is at least receiving a speed input signal and the wiring and sensor & tone ring can be assumed to be good.

This is tuff to do; suggest using str8 pins to back probe the connector

Any slight dents, chips, etc., in either the exciter ring or VSS will create needle waver. Measure air gap between the VSS and exciter ring. It should be 0.38-0.51mm (0.015-0.020"). Check exciter ring runout per the same ring gear backface runout procedure of the appropriate model 1996 Powertrain/Drivetrain Service Manual, Section 05-00. Make sure the exciter ring is mounted correctly to the ring gear. If runout is more than 0.1mm (0.004"), perform the differential runout check per the procedure in the appropriate model 1996 Powertrain/Drivetrain Service Manual, Section 05-02A or 05-02D, to find cause and repair as needed

Tone Ring Inspection; "Take off the rear diff cover. Check the Ring Tone gear. It is located on the left hand side of the ring gear. Look to see if any of the teeth have been notched (from debris floating around in the diff.) Usually a spider gear. If the ring tone gear has been notched, it will need to be replaced to fix your speedo reading. Jack it up and rotate the tires to look for the teeth to be notched/broken/bent..."

Source: by Bighibbi

more VSS info in my site @ http://www.broncolin...x.php?index=139

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More 4WABS Info, Connector Location and pin out diagrams etc in my site @ http://www.broncolinks.com/index.php?index=139

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Last;

a long shot..

PSOM Inoperative, Short Circuits, Common Locations TSB 95-02-11 for 92-95 Bronco & F Series; SEE C, E4OD Harsh Shifts & D, Code 452 - see Poss. Short Locations: 1. Driver's side A pillar trim screws may have been installed thru da 17K745 Sun Visor wire assy & .. bullet connector; 3. Scuff plate screws (driver's side) may pinch the 14A504 wire assy; 4 14401 wire assy may be trapped/pinched between Half car beam & instrument panel attachment (repeated as #7. the wire harness may be pinched/shorted behind the dash where the 14401 wire assy may come in contact w/a sharp edge on dash panel wall 5. shift cable assy near tranny may chaf the wire harness; the wire harness ; 7. repeated above..brake pedal-to-dash panel wall weld

Source: by Ford via Steve83 (Steve, That dirty old truck) at http://www.supermoto...ry/media/646262

Do this Last;

Speedometer Inoperative in TSB 95-5-21 for 92-95 Bronco & F Series; "...the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may become chafed and the vehicle could exhibit any one of the following conditions....ISSUE: On some vehicles the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may become chafed and the vehicle could exhibit any one of the following conditions:

ABS light on

Speedometer inoperative

Back-up lamps inoperative

Daytime running lamps inoperative

Trailer battery charge relay inoperative

MIL on, displaying Codes: 172, 173 or 41 for HO2S failure

Inadvertent PCM Self-Test

Perform self test KOEO and KOER, service any codes. : ..." READ MORE

Source: by Ford via Chilton @ http://content.chiltonsonline.com/TSB/displayTSBHandler.ashx?assetID=37000&key=6kAUBD5BruOJf%2f3tgozUqjXM3RdbjcQqW4sVWiE%2fp2IojfpfKqM07dr61%2bQAWHtT%2bshJrOWtEbHwvhgsAZPzfPNEDgviKncqfc3mHkrzcEoEdL99Ph3Gujftuw%2f3sDBIxZEqFQle7s1xdai2HmgR%2bA%3d%3d

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Also get the Codes scanned for Free

The engine temperature must be greater than 50°F (10°C) to pass the KOEO and greater than 180°F (82°C) to pass the KOER.

Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.

Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.

Do Key On Engine Off (KOEO) portion first.

GL!

 

[Rons beast]

Check your battery to engine ground. These can get a corroded connection at the block and have an effect on all the electrical components on the engine.

The lights, horn,ect. would not be effected, if they get their ground from the "pigtail" mounted on the fender.