1985 F-250 Auto, reverse lights intermittent

classic Classic list List threaded Threaded
7 messages Options
Reply | Threaded
Open this post in threaded view
|

1985 F-250 Auto, reverse lights intermittent

6.9-250
When in reverse the lights flicker, or stay on, or sometimes off.  I have to move the shifter just to where it engages reverse for the lights to stay on (which almost takes it out of reverse).  

I checked my service manual and it says to refer to group 16 (not sure what "group" is).  I went to section 16 and it references manual transmission.  I checked the evtm and they show exactly where it is on the manual, not auto.  They say the location of the switch is either on the trans or neutral safety switch.

If its in the neutral safety switch..is it adjustable or the switch requires replacement?
1985 Ford F-250, 6.9L, Auto C6, 4x4 208F, Extended Cab
Reply | Threaded
Open this post in threaded view
|

Re: 1985 F-250 Auto, reverse lights intermittent

Gary Lewis
Administrator
You may have a bad switch or a bad connection to the switch.  The switch is on the side of the transmission, and you can find it by following the two wires that go to it - Pk/O and Bk/Pk.  If the connector is plugged in well then I think the switch is bad.  I had to replace one recently.
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Reply | Threaded
Open this post in threaded view
|

Re: 1985 F-250 Auto, reverse lights intermittent

85lebaront2
Administrator
In reply to this post by 6.9-250
It is adjustable, but chances are the switch may be bad, There are 4 wires going to it and on my 1986 the plug was at the transmission crossmember to frame attachment on the driver's side. The switch is a curved plastic assembly and requires removal of the downshift linkage.

Don't mind the backwards switch position or strange linkage, I was in the process of switching to a 1996 interior and had to adapt the cable shifter to the existing C6. Hole circled is for setting the switch, the new one will come with a pin in that hole to hold the switch in the neutral position. It is installed and the pin removed after tightening it down.
Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

Reply | Threaded
Open this post in threaded view
|

Re: 1985 F-250 Auto, reverse lights intermittent

6.9-250
Thanks for the advice.  It put me on the right track.  The reason I could not find it in the shop manual is because I needed to look under the neutral safety switch. While they don't reference the backup switch being part of the neutral safety switch, they do mention after setting the neutral safety switch to check if the reverse lights come on.  The manual transmissions have an actual dedicated switch in the transmission.  The setup instructions are in the shop manual.  

I am not going to bother trying to set the current neutral safety switch as it may be worn out. They are not expensive and if that's the original one on the truck, it has served its time, lol.  
1985 Ford F-250, 6.9L, Auto C6, 4x4 208F, Extended Cab
Reply | Threaded
Open this post in threaded view
|

Re: 1985 F-250 Auto, reverse lights intermittent

6.9-250
Installed a new STANDARD MOTOR PRODUCTS NS26 and the reverse lights are working perfectly now.  The shop manual refers to setting the switch while installed.  This was not going well.  I ended up taking it back off and setting it on the bench (inserting a small drill bit and turning it until all the holes line up).  Done while in neutral position.  
1985 Ford F-250, 6.9L, Auto C6, 4x4 208F, Extended Cab
Reply | Threaded
Open this post in threaded view
|

Re: 1985 F-250 Auto, reverse lights intermittent

Gary Lewis
Administrator
That's an interesting trick!  I've not adjusted one of those switches, but hope to remember that if I do.  

Glad you got it working!
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Reply | Threaded
Open this post in threaded view
|

Re: 1985 F-250 Auto, reverse lights intermittent

85lebaront2
Administrator
In reply to this post by 6.9-250
The drill is exactly the preferred method on these. The Motorcraft one I installed on Darth years ago came with a plastic pin to hold it in the neutral position. The MLP (manual lever position sensor) on the E4OD adjusts in a similar fashion.
Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413