electical help needed
Thread Starter
|
New User
Joined: Feb 2015
Posts: 5
Likes: 0
electical help needed
i have a 1988 F150 with a 351w. one day my running lights quit working excluding the headlights, brake lights and turn signals still worked. listened to my dad and grand dad changed the switch and a relay also made a jumper from the headlights to the running lights so they would work and it did until i went to start it woud not start has spark and you can hear the fuel pump come on and smell it a little bit when trying to start. then the headlights are now on with the switch off and its not touchin any other wires and i unplugged the switch to see if that would help and it didnt. what did they screw up on it.
Fleet Owner
Joined: Aug 2005
Posts: 23,668
Likes: 301
From: Easton,Ks
You do not have a relay for lighting so I do not know what you changed unless it was an add on for fog lights, or something that Canada requires.
Remove the wire you added and then find out why the lights do not work.
When you say running lights I am not sure what you are talking about. Do you mean marker lights or some running light in the grill that says the ignition is on?
Remove the wire you added and then find out why the lights do not work.
When you say running lights I am not sure what you are talking about. Do you mean marker lights or some running light in the grill that says the ignition is on?
Postmaster
Joined: May 2003
Posts: 3,310
Likes: 9
From: E.Lincoln County, NC
Remove the jumper!
LIGHTING DIAGNOSIS FROM FSM
Symptom:
All tail lights and marker lights out-headlamps OK
Possible causes:
1.Loose wiring connections
2.Open wiring or poor ground
3.Blown Fuse (fuse #4, 15A opposite corner from flasher)
4.Damaged headlamp switch
LIGHTING DIAGNOSIS FROM FSM
Symptom:
All tail lights and marker lights out-headlamps OK
Possible causes:
1.Loose wiring connections
2.Open wiring or poor ground
3.Blown Fuse (fuse #4, 15A opposite corner from flasher)
4.Damaged headlamp switch
Fleet Owner
Joined: Aug 2005
Posts: 23,668
Likes: 301
From: Easton,Ks
Think Canada on this thread.
Postmaster
Joined: May 2003
Posts: 3,310
Likes: 9
From: E.Lincoln County, NC
Nobody had replied and I see you did as I was also checking out the wiring so I'm guessing/assuming at this point also.
No DRL listed in the 'Merican manual. The headlamps are on a separate circuit, not fused but with a fusible link.
A primary failure of this tail/parking/marker light circuit is faulty add-on trailer wiring.
Thread Starter
|
New User
Joined: Feb 2015
Posts: 5
Likes: 0
There were two relays behind the air cleaner and they thought one them was bad so we replaced it and with running lights yes I do mean the side marker lights instrument cluster and tail lights I clipeed the jumper wire they and now with the switch off and hooked up batter lights come on
Thread Starter
|
New User
Joined: Feb 2015
Posts: 5
Likes: 0
Trending Topics
Fleet Owner
Joined: Aug 2005
Posts: 23,668
Likes: 301
From: Easton,Ks
The two relays are the power relay and the fuel pump relay.
Neither relay has anything to do with the lighting./
Neither relay has anything to do with the lighting./
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Post Fiend
Joined: Nov 2005
Posts: 7,437
Likes: 4
From: Charles Town, W bygod Va
These trucks have too small wiring for the headlights. They are known to melt tbe wiring at the plug for the headlight switch. Check there for wires melted together. After you fix the short you can install headlight relays to reduce the load on the circuit so it wont happen again.
Thread Starter
|
New User
Joined: Feb 2015
Posts: 5
Likes: 0
It looks like it's brand new and no melted wires the truck had been sitting for awhile and with its age maybe the wires going to the fire could have a short I lookied inside the cap and there's no signs of a short or bad wires
Thread Starter
|
New User
Joined: Feb 2015
Posts: 5
Likes: 0
Update
Lights work now but fuel pump stays on when battery is hooked up. When switch is on the front tank the pump behind fuel filter stays on and when on the rear tank the pump inside of it stays on. The fuel pressure regulator holds vaccine and still have spark just won't start is this possibly the pcm
Thread
Thread Starter
Forum
Replies
Last Post
facets
Electrical Systems/Wiring
2
Feb 15, 2014 04:46 PM
J-W
1994.5 - 1997 7.3L Power Stroke Diesel
1
Mar 6, 2011 04:52 PM