hopefully easy wiring/fuse issue

The place to discuss problems and routine maintenance questions and tips that are NOT specifically diesel-related.
arz
Regular Member
Posts: 268
Joined: Wed Apr 27, 2011 5:52 pm
Location: Lizzy, CO

hopefully easy wiring/fuse issue

Postby arz » Mon Oct 14, 2013 9:37 pm

81 Pup. 2wd diesel, but that part shouldn't matter.

1. brake lights don't work. turn signals and rear markers are fine. Which fuse? they all look good.

2. wires from distribution center under dash to underneath driver seat. what are they for?





I hate electrical gremlins.
1981 P'up diesel. base trim. pretty close to bone stock.

southernal
Regular Member
Posts: 26
Joined: Tue Jun 18, 2013 3:40 am
Location: south island New Zealand

Re: hopefully easy wiring/fuse issue

Postby southernal » Tue Oct 15, 2013 2:11 am

have you checked your brake light switch ,, switch is via a bracket that touches your brake pedal , when you brake , the switch should be free to open and complete the light circuit... sometimes they crap out , is difficult to see as they are a throw away part.

if you block the brake pedal to the seat so it is "braking" , then move the switch in and out ( you should a small knob) get someone to stand behind and watch the lights to see if the flash . if not replace the switch .(?) ,, you could also pull the bulbs and check theres no rust etc in the socket that may cause a failure ..

Luck Al

arz
Regular Member
Posts: 268
Joined: Wed Apr 27, 2011 5:52 pm
Location: Lizzy, CO

Re: hopefully easy wiring/fuse issue

Postby arz » Tue Oct 15, 2013 12:26 pm

I'll check that but the 4way flashers don't work either
1981 P'up diesel. base trim. pretty close to bone stock.

User avatar
puttputtinpup
Regular Member
Posts: 10512
Joined: Sat Oct 08, 2005 5:18 am
Location: Winston Salem, NC

Re: hopefully easy wiring/fuse issue

Postby puttputtinpup » Tue Oct 15, 2013 1:49 pm

arz, the 4ways are a different circuit than the brakes. For the 4ways, try pulling the 4way switch in & out a few times. Sometimes the switch gets 'stuck' inside between turn signal mode, and 4 way mode.
Brakes: If checking the switch at the pedal doesn't help, pull one of the bulbs and swap it w/ a new one. Bad ground? Bad connection? Burned out bulb? Also check the harness underneath for corrosion in the connector.

arz
Regular Member
Posts: 268
Joined: Wed Apr 27, 2011 5:52 pm
Location: Lizzy, CO

Re: hopefully easy wiring/fuse issue

Postby arz » Wed Oct 16, 2013 5:38 pm

here's where I sit at the moment.

wire in question that runs under the driver seat is, as suspected, the switch indicating that the seat belt is buckled.


I detached the two bullet connectors to/from the brake switch. I bypassed the switch which should have made the lights come on all the time if the switch was the culprit. Lights do not come on. tested both sides of the harness to the switch and neither end is hot.

the fuses in the fusebox under the hood all test good. please tell me there are fuses somewhere else as I really HATE tracking down wiring issues. I'll be much more likely to put in a new circuit from the switch to the tail lights.
1981 P'up diesel. base trim. pretty close to bone stock.

User avatar
puttputtinpup
Regular Member
Posts: 10512
Joined: Sat Oct 08, 2005 5:18 am
Location: Winston Salem, NC

Re: hopefully easy wiring/fuse issue

Postby puttputtinpup » Wed Oct 16, 2013 5:45 pm

paul recently told us about a breaker/fuse under the dash somewhere, but off the top of my head can't remember exactly where it was, or what it was for. headlights maybe??

User avatar
puttputtinpup
Regular Member
Posts: 10512
Joined: Sat Oct 08, 2005 5:18 am
Location: Winston Salem, NC

Re: hopefully easy wiring/fuse issue

Postby puttputtinpup » Wed Oct 16, 2013 5:46 pm

i'd check the wires under the fuse block, or take the fuses w/ a pair of pliers and slide them in & out to maybe re establish connection if they're corroded.

User avatar
FlukeGE
Regular Member
Posts: 400
Joined: Mon Jan 21, 2013 10:52 pm
Location: Raleigh NC

Re: hopefully easy wiring/fuse issue

Postby FlukeGE » Wed Oct 16, 2013 9:45 pm

I would slide the fuses in an out a few times like Andy suggested. If you still don't get voltage at the brake light switch do you have an meter you can measure ohms with? You can put one lead on the brake light switch and go to the fuse box to check for breaks in the wire. There are some factory junctions in that wire from the fuse box to the brake switch.

Ryan
1986 Trooper Gen III
1999 with 4JG2 Coversion

arz
Regular Member
Posts: 268
Joined: Wed Apr 27, 2011 5:52 pm
Location: Lizzy, CO

Re: hopefully easy wiring/fuse issue

Postby arz » Wed Oct 16, 2013 10:15 pm

this is actually my plan for Saturday morning. Need to get new leads that are a bit longer than the 2' I have now.

I'm running with the assumption that the female bullet connector is supposed to be the hot one... is this a good assumption? The insulation on that connector is such that it would not short to ground if left dangling. The male connector could short to ground if left disconnected. Think of it like a wall socket (female) and a plug (male).


Which fuse is supposed to handle the brake lights? Somewhere along the way, the cover with identifying which is which got lost.
1981 P'up diesel. base trim. pretty close to bone stock.

arz
Regular Member
Posts: 268
Joined: Wed Apr 27, 2011 5:52 pm
Location: Lizzy, CO

Re: hopefully easy wiring/fuse issue

Postby arz » Sat Oct 19, 2013 7:10 pm

this is driving me mad...


going to relax with the grill, a cold barley soda and get a good night sleep. tackle it first thing in the morning... again.



for those that care, or have insight:

all the tail lights work except the brake lights

tail light switch - removed and tested good. will be returning the replacement as I trust the switch.

with ignition on, there is power to the switch. and using a meter, 0 volts with the pedal up, 12 with it depressed (13.4 with engine running).


having a... challenging time figuring out where it loses power along the way. There is a connector in the engine compartment right near the wiper motor, and another behind the passenger side rear wheel. Then connectors immediately behind the tail lights.

I think I need to sit down with the wiring diagram and a magnifying glass to figure out which wire/pin is the culprit and just walk it back from the front connector.
1981 P'up diesel. base trim. pretty close to bone stock.

User avatar
FlukeGE
Regular Member
Posts: 400
Joined: Mon Jan 21, 2013 10:52 pm
Location: Raleigh NC

Re: hopefully easy wiring/fuse issue

Postby FlukeGE » Sun Oct 20, 2013 12:25 am

You are on the right track. If you have it at the brake pedal switch then those two connectors near the fuel tank and tail lights would be next on my list as well. The diagram that I have is for an 83 and it looks like pin 1 before the fuel tank and pin 4 before the T for tail lights.

Ryan
1986 Trooper Gen III
1999 with 4JG2 Coversion

User avatar
puttputtinpup
Regular Member
Posts: 10512
Joined: Sat Oct 08, 2005 5:18 am
Location: Winston Salem, NC

Re: hopefully easy wiring/fuse issue

Postby puttputtinpup » Sun Oct 20, 2013 6:30 am

yes, it could very well be the connectors, but have we checked the actual bulbs yet? Are they any good? Do we have 12v at the socket?

arz
Regular Member
Posts: 268
Joined: Wed Apr 27, 2011 5:52 pm
Location: Lizzy, CO

Re: hopefully easy wiring/fuse issue

Postby arz » Sun Oct 20, 2013 11:08 am

bulbs are good. have a hard time believing that both bulbs died simultaneously on both sides and that the new bulbs I tried also have the same filaments burned out.
1981 P'up diesel. base trim. pretty close to bone stock.

User avatar
puttputtinpup
Regular Member
Posts: 10512
Joined: Sat Oct 08, 2005 5:18 am
Location: Winston Salem, NC

Re: hopefully easy wiring/fuse issue

Postby puttputtinpup » Sun Oct 20, 2013 5:06 pm

arz wrote:bulbs are good. have a hard time believing that both bulbs died simultaneously on both sides and that the new bulbs I tried also have the same filaments burned out.
Yes, new bulbs should work if there's 12v to the socket. I once had two headlights go out at the same time, so I never assume anything anymore.

arz
Regular Member
Posts: 268
Joined: Wed Apr 27, 2011 5:52 pm
Location: Lizzy, CO

Re: hopefully easy wiring/fuse issue

Postby arz » Sun Oct 20, 2013 10:48 pm

I'm usually pretty good at diagnosing these kinds of things (don't like it, but pretty good).

totally baffled with this.

I seem to have power to the brake lights all along the way. At the underhood connector, I was able to identify and show that I have 12v when the pedal is depressed. at the connector behind the rear wheel, same. at the connector for the left rear tail light, it worked. but not at the light.

Makes me think there is discontinuity somewhere in the rear harness. If I put 12v to the harness side of the rear connector, both brake filaments light up. But if I run the 12v from the brake pedal switch, it doesn't light up.

Then the snow blew in.

I'll drive my 20 year old volvo tomorrow.
1981 P'up diesel. base trim. pretty close to bone stock.