Lights have gone crazy

[Krackah]

I've been trying to figure out what is going on but only thing I have found is a few wires that looked like they were chewed on by a mouse, I've taped them up already, and a tube that runs wiring from front to back that has been cracked open by heat from my muffler. I haven't looked at the tube that close yet, just found it yesterday. But here is what's going on.

I have found that I have two different combinations of issues that switch back and forth but haven't figured out what makes it switch.

Combo 1

Press brakes and dash lights come on but no brake lights.

Use turn signals dash lights blink with signal

Turn running lights or headlights on and turn signals freeze

Press brakes and turn signals slow down

Only front signals work

Dash lights work

No running lights

Headlights work

 

Combo 2

Press brakes and dash lights come on no brake lights

Use turn signals and dash lights blink

No rear signals

No dash lights

No running lights

Headlights work

 

Any advice on what to do or what it might be would be appreciated.

 

 

[Krackah]

1987 Newmar Kountry Star Chevy chassis

[GeorgiaHybrid]

First thing I would check is the multi function switch on the steering column. You would be surprised what a problem there will do to your lights.

[GeorgiaHybrid]

Just got a call from my buddy Mike who has forgotten more than I'll ever know about being a mechanic. He said to pull all of your bulbs and check for a broken filament that has flipped to the ground side of the bulb.

On your chassis that should be the 1157 type of bulbs that have a dim running light mode and a bright mode for brake lights and turn signals. They should have two contact points on the bottom of the bulb and two filaments inside.

Check these two areas first and let us know what you find out. Mike was not able to post but is following this thread.

[Kirk W]

Another possibility is that those items share a common ground and it has opened so that it is grounding the dash lights back through the brake lights, which have their own ground connection. 

3 hours ago, Krackah said:

a tube that runs wiring from front to back that has been cracked open by heat from my muffler. I haven't looked at the tube that close yet, just found it yesterday.

With it having been hot, it could also be that the same heat has damaged the insulation on he wires inside of it and various wires are shorting together. I would check that out before I spent too long as it needs attention even if it isn't the problem area. With a rig that is 30+ years old, there could be a lot of damage in places like that. 

[Krackah]

Thanks for the tips. I will check them out and see if any of them are the problem. 

[Krackah]

What is the multi function switch? 

[Krackah]

I have looked at the bulbs in back but I didn't pay that much attention to the contact points. Just made sure that they weren't broken. When I was working on it yesterday I noticed that the bulbs do light up but they are so did you can barely see them.

[Krackah]

Something else I noticed today is my battery gauge moves with the blinkers when turned on. And my oil gauge doesn't work at all. The gas and temperature gauges work. The battery gauge works too but just moves with blinkers

[GeorgiaHybrid]

The multi function switch is the stalk with turn signals, dimmer switch and sometimes the light switch as well.

Edited November 19, 2020 by GeorgiaHybrid

[Krackah]

I have a pull switch on my dash for running lights and headlights and then I have the signal switch on my steering wheel. 

Just checked bulbs and cleaned the connections with a wire brush. Found one bulb that had one melted side so I switched it out and still my brake lights are super dim. 

[GeorgiaHybrid]

You need to start checking grounds and the connections at the dimmer switch and the brake light switch for corrosion as well as the wiring harness connection at the bottom of the steering column.

A  12 volt test light will also help show you where an issue might be and a Power Probe might be a cheap investment at this point as you can jump around sections of a harness to help pinpoint a problem section of wiring.

Edited November 19, 2020 by GeorgiaHybrid

[Krackah]

I have a test light and a multimeter. Been trying to get to the brake light switch, but it looks like I am going to have to remove my driver's seat in order to get to it. Otherwise I can't reach it. As far as ground wires go, I have been and still am trying to find them all. It's super difficult to get behind the dash, I know a few are back there. The ones I have been able to find seem to be ok. 

It's getting super frustrating and so I really appreciate all of your input. Finally feeling like there is a light at the end of the tunnel.

[Ray,IN]

3 hours ago, Krackah said:

I have looked at the bulbs in back but I didn't pay that much attention to the contact points. Just made sure that they weren't broken. When I was working on it yesterday I noticed that the bulbs do light up but they are so did you can barely see them.

That is the primary indicator of a poor/missing ground from the body to battery Neg. post.For a test use a spool of 16 ga. wire, run it from a brake light bulb ground wire directly to battery neg. post

Edited November 19, 2020 by Ray,IN

[Krackah]

Ok, I will double check the grounds for the brakes, they are probably the hardest ones to get to that I have found so far. 

Thanks for your reply

[Kirk W]

We used to own an Allegro that was on the 1987 Chevy/GM chassis so I have some familiarity with it. As I read your description of the symptoms, I would think about what seems to work correctly and analyze what doesn't work right and how it might happen. I would agree that this does sound like a ground problem, but there are a lot of grounds to check so it would help if you know where to look first. Have you inspected the wires in that tube that shows heat damage? It would go a long way to know that those wires are all good.

On 11/14/2020 at 3:14 PM, Krackah said:

Press brakes and dash lights come on but no brake lights.

Consider what could possibly cause this to happen. The brake switch supplies 12V to the brake lights which (if working properly) then passes through the bulb and out through the ground connection to return to the battery. The electricity must always have a path back to the battery so if you remove that ground, might the power then return back to the dash and use that ground? If you have someone to apply the brake, remove the lens from the brake light and watch to see if both the brake and the running light elements are lighting, very dimly? If they are that will tell you that you do not have a ground return path and it is returning via the second element to some other ground point. I would then use a jumper wire to supply a good ground or if you have enough wire connect the other end to the negative battery post and attach it to the ground point on you brake light assembly and see if that makes it work properly. If so, you have found the problem. 

Analyze each of your symptoms in this manner. You need to break the symptoms down into small enough bites to be able to eliminate the possibilities one at a time. If you keep jumping around from one symptom to the next, you will have an insurmountable problem. Having 40+ years of electrical troubleshooting taught me to always use a step by step process.

Edited November 19, 2020 by Kirk W

[Krackah]

Well a friend of mine came over and helped me out. Lights work as they are supposed to now. Had to replace some wires, I am really not sure what all he did but he brought up a wire that was chewed up pretty bad by a mouse or some other kind of vermin. 

You guys are great and I really appreciate all of your help. It was definitely a learning experience for me and I am happy to have had the chance to learn.

 

Thank you all so much!