Blinker issues,

[texashawk001]

Having issue with the front blinkers on my 1990 Ford Bronco. Rear blinkers work but my front ones do no on either side. Had some after market headlight assemblies on the vehicle when I purchased it. I changed them out for some better assemblies that are LED. Was having the issue before I changed assemblies.

 

[miesk5]

Yo texashawk001,
Welcome,

●
Here are the 1990 Bronco Pre-Delivery Shop & Electrical & Vacuum Troubleshooting Manuals (EVTM), Partial by member Kingfish999 in Google Drive @ 1990 Ford Truck service manuals - Google Drive
&
1990 Ford Truck Emissions Manual.pdf by Ford via member 90.CaliBronco in Google Drive @ 1990 Ford Truck Emissions Manual.pdf

Suggest you download both for faster scrolling and to use the table of contents index.

1990 Ford Bronco Brochure by Ford via Dezo's Garage @ https://www.xr793.com/wp-content/uploads/2020/07/1990-Ford-Bronco.pdf

Haynes Red Manual for 80-95 Bronco & F Series @ Hanes guide 80-96 bko f series.pdf found by Mrs BroncMom!
Al

 

[miesk5]

Yo, part 2
My download file is messed up today,so some may be duplicates

 

[miesk5]

3rd

 

[texashawk001]

Thank you for the diagrams. I hope this will shed some light on my issues. Not only are my blinkers not working on the front of the vehicle but my turn signal indicator lamps no longer are working on the instrument panel. Also my voltage gauge is jumping around and the oil sending unit is showing low oil pressure. None of this except the front turn signal lamps were an issue until I replaced the circuit board on the instrument cluster.

 

[miesk5]

Yo texashawk001,
Suggest you consider doing this Installation, Sunpro,w/T for stock oil pressure gauge in an 86
Source: by Sixlitre (Malcolm H, Eddie Bauer) at SuperMotors.net
Oul Pressure Gauuge 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)..." 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. Wrap some teflon tape around the threads and install. 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..." miesk5 Note; The stock gauge & Sender will drop off after pressure reaches a certain level. You might actually have 5 psi, but the gauge will read 0 PSI & "...Technically all you need is 10 psi of oil pressure per 1,000 rpms . I still would not feel comfortable with less then 20 psi at idle. If it is lower then that, you can also get a thicker oil." by 420nitro
Source: by Canoeboy146 at FSB

"The voltmeter is a gauge which measures the electrical flow from the battery to indicate whether the battery output is within tolerances. The voltmeter reading can range from 13.5-14.0 volts under normal operating conditions. If an undercharge or overcharge condition is indicated for an extended period, the battery and charging system should be checked."


"ISSUE: The Low Oil Pressure/High Coolant Temperature Warning Module that operates the "ENGINE" warning light was deleted on trucks built after March 15, 1990. Service information for affected trucks has changed in the 1990 Bronco/F15O-F350/F Super Duty EVTM page 60-1A and the 1990 Econoline/F-Series/Bronco Truck Shop Manual page 33-51-7."

 

[texashawk001]

Thank you for the information you sent me. I am learning that this bronco is actually not a 1990. It is in fact a 1988 with a 1990 front end on it. It seems that the vehicle was wrecked and the front clip had to be replaced and they used a 1990 to replace it with. I can tell you that before I change the printed circuit board on back of the instrument cluster the oil pressure gauge was working correctly and the volts gauge was not bouncing back and fourth. And the turn signal lights for the blinkers worked as well. So I don't know if the printed circuit board (new) is the issue or something else is going on here. Any insight you can send my way is much appreciated.

 

[Tiha]

Just for curiosity sake, do they work if you turn the hazards on?

If you can follow the wire diagram the front and rear are separate circuits in the turn signal switch. That is because the brake light circuit passes through the turn signal switch.

I would probably start with pulling the covers off the column and testing for front and rear blinker voltage at the switch. It could very well be a bad turn signal switch.

 

[texashawk001]

To answer your question, no the front's do not work with the hazards on,

 

[johnnyreb]

Check the bulbs. If they are SILVER TIP-instead of BRASS. They are made in CHINA. They are junk. I went trough that deal on my 78. Some of the fillament was also broken. Try and get AMERICAN MADE or GO AND GET SOME OFF OF A OLD JUNK VEHICLE. Good luck. Alos check the light sockets. Same thing to look for. China junk if they are silver lined.

 

[Shaggy]

Having issue with the front blinkers on my 1990 Ford Bronco. Rear blinkers work but my front ones do no on either side. Had some after market headlight assemblies on the vehicle when I purchased it. I changed them out for some better assemblies that are LED. Was having the issue before I changed assemblies.

How do you like the new LED assemblies?

 

[George Coleman]

This may be a long shot but I had this happen about 4 months ago, I bought a good quality turn signal switch and plugged it in and no more problems? do not by the cheap ones!

 

[Rons beast]

You did not say if your front turn signals were LEDs. If so that may be the problem. They do not provide enough resistence for a normal flasher to work.
Another thought is the ground is not good. If the front clip was replaced it's a good chance that the ground strap was left off. I would provide a new ground wire to the light harness, terminated at a quality ground direct to the battery.
The wonky issues with the guages sound like a "search for ground" issue.
Good Luck