headlight switch or starter switch

broncobuckinaround · Aug 1, 2015

driving to work and b2 shuts off. smokes starts coming from under the hood. found that an orange fusible link decided to burn up.

i replaced the starter switch cause it was coming apart. didnt see anything wrong with the head light switch.

ive found that when the headlights are on the wire is grounding causing the in line fuse i put in to replace the link. btw that fuse is 30 amps.

being the power wire coming off the starter relay shouldnt have ground going to it.

my apologies if this makes no sense.

burnt fusible link, replaced with 30 amp in-line fuse, pops running or not seems like but not sure. could be starter switch or could be headlight switch i need help diagnosing this

RonD · Aug 1, 2015

Well the head light switch has power all the time, and it is on it's own wire(black with orange stripe in '86) so I would remove that fuse, hook battery up(key off) and see if head lights work.

If they don't then yes that fuse is for the head light switch and either the switch or one of it's wires is shorted out, remove switch and inspect connector, if fusible link melted then you should also see damage to light switch connection where the shorted wire hooks up, but it could just be the switch that shorted out, not uncommon.

You can see wiring diagrams here: http://www.autozone.com/repairguides/Ford-Ranger-Bronco-II-1983-1990-Repair-Guide/WIRING-DIAGRAMS/WIRING-DIAGRAMS/_/P-0900c152800781b2

Only orange fusible link I saw for '86 was for alternator circuit and it does go to ignition switch.

Spott · Aug 1, 2015

Do you have a test meter? In order to troubleshoot this, you'll need one.

broncobuckinaround · Aug 2, 2015

spott. yes i have a multimeter

rond. if i take out the in-line fuse i put in the head lights dont work. alone with everything else. nothing works. i checked the connector, there are no burnt wires there.

but when i take out the fuse, with my test light hooked to positive on the battery there is ground coming from the switch. only when the switch is on. i noticed i just barely have to pull and it shows ground. plus when i put the fuse in it arcs like lil sparks.

and yes they go to the alternator as well. ive got it unwrapped and the blk w/ org wire fuses with yel and white. which fuses with the same colors that go to the alternator.

im thiniking its the switch grounding out too. but im just trying to be certain

RonD · Aug 2, 2015

There should be several fusible links on the starter relay post with the Positive battery cable.

Head light switch should have its own fusible link(fuse) not shared with anything else.

With head light switch unplugged does test light come on?
If it does then that wire has the short or someone has "tapped" into that wire, usually in the cab to add a CB or other device they wanted full time power for.

Testing the head light or parking light wires is harder since they ARE a ground, light bulb is just straight wire that heats up, but high resistance so OHM meter might be better for testing, one meter wire on a good ground other wire on wire to light bulb, should read high ohms, 0 ohms is a short.
If you have a light bulb just test it to see expected OHMs when testing the wires.

broncobuckinaround · Aug 2, 2015

yes blk and orange wire on the headlight swtich unplugged has ground

broncobuckinaround · Aug 2, 2015

ron i need you cell number so i can send pics to you. because you said its not spliced. but what im seeing is a splice. PM you cell so i can show you what im seeing

RonD · Aug 2, 2015

Oops, my mistake

Found this diagram: http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_Headlights_1983to1989.JPG

The headlight switch power wire and fuse also power some of the circuits in the fuse panel

broncobuckinaround · Aug 2, 2015

ok ron i cut the blk orgn wire and ground still came through. so its not those links. ground was still at the connector. but check this out. i trace it further and it goes into the fuse panel. shares a fuse with a small light green with yellow stripe to a mess of wires. any how i pulled the fuse and checked to see if ground was still there and it isnt. but the green wire has ground. so something on that circuit is being grounded.

what a night mare. ill keep you posted

broncobuckinaround · Aug 2, 2015

found another spot where ground should be power. i havent go a clue what this thing is. its a black box drivers side up in the dash against the side. not on the fire wall. what the heck is that.

broncobuckinaround · Aug 2, 2015

fixed fixed fixed :yahoo:

found where the short is. dome light. all the light green with a yellow stripe are lumination wires. all of them had ground when they were power wires. i pulled the cover to it and the housing is cooked. i had to pull to rear light as well because it is part of that circuit. and yup no ground. its back to normal.

txgocartB3000 · Aug 2, 2015

Alright!

Ray

RonD · Aug 3, 2015

Light Green/yellow stripe(LG/Y) wires are used for interior lighting in this diagram: http://www.therangerstation.com/tech_library/EDiagrams/files/Diagram_domecargo_1983to1988.JPG

Also under hood lamp wire, which can short out

oops, I missed that you already found it

Good work :icon_thumby:

headlight switch or starter switch

Member

Official TRS AI

Member

Member

Official TRS AI

Member

Member

Official TRS AI

Member

Member

Member

New Member

Official TRS AI

Sponsored Ad

Sponsored Ad

Member & Vendor Upgrades

Truck of The Month

Recently Featured

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store

Sponsored Ad

Sponsored Ad

Sponsored Ad

Amazon Deals