1986 XLT Misc Questions

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Kauffmanbros

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Hey guys, new to the forum and thanks in advance for any help. I've recently (5/14/16) just picked up a 1986 XLT 351 Automatic with a few known issues. My brother has an 86 he's owned for about a year and we'll be building these as camping and trail rigs. Don't want to get mud up to the floor boards or crawl rocks, just want a reliable rig to take into the woods. It runs like a dream when driving, but a few of the creature comforts and a couple larger issues I need to get my hands on.

1) Seems to have some trouble starting. I have to run the starter longer than what I should. When it runs the carb seems to be tuned well, new plugs and wires, air and fuel filter seem clean, and my brother who knows more than I do says timing is great. Just a matter of getting actually running. I haven't really seen a difference with cold mornings, warm engine etc. I've pulled the inspection plate and the teeth on the flex plate could look a little better but they're not awful. Oh and a big piece of info! After bringing it home I pulled the starter and the spur on the starter had missing teeth (autozone reman starter). I've since replaced with something quality. Has definitely helped, but still requires a little more cranking at times than it should.

2) White reverse lights don't work. All other indicators and bulbs are fine.

3) Driver and passenger windows won't roll down. The rear glass works great from the interior switch or exterior key switch. The guy that I bought it from said they worked a few months ago. Then they worked intermittently, then quit all together. I've checked the 20amp fuse under the steering column. I'm thinking bad ground, but don't know where to look.

4) Fuel gauge reads empty all the time. I know it's likely the sender but want to verify before just throwing parts at common issues. I'll be dropping the tank if I'm able to on Saturday 5/21. Is it usually possible to clean or repair these? I'm trying to watch cost like every other guy.

5) The driver side lock feels like it's binding when you push on the little silver rod. I've got the interior door panel off and have reached back there to see if I can feel anything obvious, but no dice. I think the electric locks would work if that would move like it should (passenger side works fine). How does the locking mechanism work? Any diagrams/pictures?

Any help on any of these would be really awesome. I'm wanting to take it out on a 3 day logging road adventure (live in Oregon) over Memorial Weekend. Thank you guys for any help in the right direction.

1986 Bronco (full size) XLT

Auto Trans

351

 

miesk5

96 Bronco 5.0
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Yo,

Welcome!

Will answer your first issue now. I am using a tablet and it is difficult for me to copy and paste info and we try to limit questions to one per post. And often the responses expand into multiple pages.

So get in the 80-96 Ford Bronco Tech Support and enter each issue or two in separate posts.

1. Has battery been load tested?

Are starter, battery, etc. cable connections, as well as ground cables clean and tight?

Here are some possible carburetor causes for cold/ warm starting issues, although they do not directly address your problem... looking at "Engine cranks but will not start" in both cold and warm conditions.

http://www.recarbco.com/cold-starting-problem

http://www.recarbco.com/warm-starting-problem

Electrical issues:

Slow Cranking or a Grinding Noise; "... Problems with the negative battery cable is a major cause of starting problems in Ford, Lincoln, and Mercury vehicles. Bad battery cables can cause slow cranking or a grinding noise when trying to start an engine. On some late model vehicles dating back to 1994, the wire connection inside the battery terminal connector corrodes easily. This will cause a voltage drop in the cable and result in low voltage being supplied to the starter. You can check for voltage drop in the cable using a digital voltmeter. Connect the negative probe of the voltmeter to the negative battery post (not the battery terminal connector). Then connect the positive probe to the starter case and crank the engine. The voltage reading should be less than .5 volts. A higher reading means there is resistance in the cable or the battery terminal connector. Clean the cable end and the battery terminal connector and test again. If the voltage reading is still higher than .5 volts, replace the cable and the battery terminal connector..." by Gen of

"...Why are the cables and battery so important? The starter circuit pulls a lot of amperage, up to 500 amps depending on the starter, the engine load, and battery condition. This kind of amperage stresses all of the components in the starter circuit, including the battery, battery terminals, the battery disconnect switch, the cables including the ground path, and any remote solenoids. Problems with these components are hard to find because they appear fine at rest or under a light load, but generate high resistance under heavy amperage draws. The result will be low voltage to the starter during cranking, resulting in heavier amperage draw and increased internal heat in the starter. Over time, this will cause starter failure. Voltage measured at the starter during cranking should always be above 9.5VDC..." by powermastermotorsports.com

 

fordblood

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Problem 3:

When you try to follow the windows down, do you hear the power window motor turnin

 
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Kauffmanbros

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No it's completely dead just as if there was no fuse. I've tested the switch and it's good. I've got new motors and regulators ordered but really think I'll need more than just that since they both failed at the same time. I've tried doing some continuity tests like I outlined here. http://broncozone.com/topic/25292-1986-xlt-power-windows/    I really appreciate the help on this.

 

fordblood

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Have you checked for voltage where the harness plugs into the motor? Have you checked for voltage at the power window switch?

 
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Kauffmanbros

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Have you checked for voltage where the harness plugs into the motor? Have you checked for voltage at the power window switch?
I haven't done either. I'll do that tonight, and reply back with findings. Thanks dude!

 

Seabronc

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Fuel gauge.  Be careful with this bomb, You may want to check the connector at the tank first, remove it and check for corrosion on the pins.   It's a little difficult to reach without lowering the tank but possible.  With it off check for voltage.  The diagram shows both the Bronco and pickup dual tank circuits, just ignore the dual tank stuff.  The ground for the tank is all the way back to the instrument ground,sometimes one or the other of these wires get broken.

Sender unit is not repairable, it is a simple resistive strip which wears out over time.

Another possible problem is that the float is bad and stays at the bottom.

Good troubleshooting

:)>-

PG6.jpg

Grounds_2.jpg

PG58.jpg

PG59.jpg

 

Seabronc

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P.S.

Check the ground cable from your battery (-) to the frame and engine.  Remove and clean all connections before reconnecting.  If the cable from the battery shows any corrosion where the lugs connect to the cable, replace it.  Also check the connection from the driver side of the intake manifold to the fire wall, it is a vital ground connection for ground 701 shown in the diagram above.  Read the two posts above.

:)>-

 

fordblood

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With no voltage with key on, still check the fuse with your meter to ensure it is good. Then if it is good check for continuity in the wire from the fuse box to the window motor. Probably wouldn't hurt to see if you have voltage at the fuse box supply side of the fuse also.

 

miesk5

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