Dougs951S

Took the 86 for the first drive today, it ran great. The high idle seemed to sort its self out and it idled at ~1050 rpm when it was warmed up which is acceptable to me.

I noticed when I got back the tail light and rear side marker were out on the driver side. The bulbs are new. I checked the fuses but it doesn't specifically list which fuse is for the driver side lights. My brake lights work fine on both sides. All my lights worked fine when I parked the car 6 months ago. Where should I start troubleshooting?

is fuse #40 the proper fuse for the driver side lights?

Dougs951S

Always check fuses with a multimeter kids. Fuse 40 had an invisible break not detectable with the naked eye. I havnt checked yet but I assume that fixed it.

Dougs951S

just moved and dont have wifi yet, typing on my phone so I'll try to be brief.

Car blows fuse #40 as soon as I turn the lights on, which is the fuse for the left side running lights. headlights work fine, the left hand side front and rear turn signals work even though the running ligjts dont, and they are just different filiments on the same bulb. The left side turn signals flash really fast when i use the stalk, but all flashers flash normal speed if I use the 4 way flashers. Not sure where to start troubleshooting this.

Scott at Team Harco

Doug - It's almost always wiring. You may have a short to ground which blows the fuse. You have a wiring diagram, yes? Check Clark's garage, if not.

Trace the wires and check all connectors. Clean and grease them before reassembling. The metal plate in the taillight assembly can be a source of trouble as well, if you have any corrosion there.

When I read the title - I expected this to be the problem I have been experiencing with various bulbs on our cars. Corrosion, be it ever so minute, builds up on the contacts. Cleaning and bending the "hot" tab usually brings them back to life for a while. But they still want to find the happy spot where no contact is made.

The right brake light on Goodwench's car is becoming a real bugger. I am convinced it's in the wiring. Finding an intermittent break in the wiring is a pain in the butt.

Dougs951S

i agree Scott, just trying to analyze the information the car is giving me and understand what it means that the flashers are flashing too fast using the turn signal stalk, but normal speed using the 4 way. I suspect that is an important detail but I dont know what it means.

I believe this is the relevant diagram:

http://www.pelicanparts.com/944/elec...944_84_2_2.jpg

odonnell

Maybe you got a bad bulb when you replaced it. Have you tried switching the bulbs to see if changes to the other side? Any water in the housing?

marc abrams

The under the hood light gets its power from the left side parking light circuit. I would start with that first.

mrgreenjeans

the infamous " underhood light ".......

are there actually some of these working ?

Every single one I have ever looked at has been burned out, non working, or refuses to function even after repeated attempts to r and r. They are next to hopeless.

If you want light underhood, use a nearby street light or carry a small flashlight on your keyring /-;}

marc abrams

Mine works!

Dougs951S

Marc, I had no idea the hood light was tied to the running light circuit! Mine does not work; certainly they are not in series; but perhaps you are implying that a short under the hood might affect the running lights? Simply having the light inoperative would not also render my left side running lights inop?

i have messed with that circuit recently since i had the hood off to do my engine swap....I just unplugged it since it didnt work. since fuse 40 keeps blowing though, it seems I have a dead short to ground somewhere.

mrgreenjeans

half of mine work; all the low mileage units or those that have never been run in inclement weather, or have a new socket installed, and / or fastidiously cleaned.

The rest.... well, they are at the end of a 'short' list of more pertinent efforts

Dougs951S

Marc is the winner. Turns out the underhood light didnt work because the hot wire was grounded! I fixed that and now the underhood light works and my tail lights work. Thanks!

marc abrams

Good to hear! Thanks for the follow up Doug.

Dougs951S

Coming back to this again, this problem keeps resurfacing. I had the lights working fine for a while after
i noticed some of the wiring pigtail leading to the underhood light was frayed; so I simply snipped the entire pigtail figuring I'd solder it back together properly later. The lights were all working fine, I took the car for a drive and when I got back I noticed the issue had returned and the fuse was blown. Here are some pics I took testing with my test light. As you can see, one side of the circuit is hot and one side is not. I have sliced away all the wiring to the underhood light all the way up to the molex connector hidden under the hood's sheet metal that contains the contacts for both the underhood light and the windshield washer sprayer mechanism. I am not even 100% convinced now the issue is in the underhood light circuit, and could really use some help tracking this issue down. I assume it is helpful to note which side of the circuit has power even though the fuse pictured is blown? Whereever the dead short is, it's got to be on that side but I'm not sure how to interpret that into further troubleshooting. The circuit is hot on the right hand side of the fuse, whatever that means.

Dougs951S

No power to underhood light, no power to front or rear running light on left side, front turn signal works but blinks very rapidly. This is driving me crazy.

The front turn signal and running light are two filiments on the same bulb and share a ground. The rear running light and front running light are wired in series.

Edit: PROBLEM SOLVED! I don't currently have my front side markers installed since I had the front splitter off during the engine swap. The hot and ground for the side marker on the left side were touching each other...it was a coincidence that they shifted enough to not touch after fidling with all the wiring, including the underhood light.


Got to love these cars; they keep our investigative and problem solving minds sharp!