Electrical issue with lights and blown fuse

[timmy2]

Are you taking the readings with the fuse removed?
Also with the lamps removed?

[ace123]

Here is the summary of the ohm test:

Fuse out, Key out of ignition switch, test from bottom of fuse to neg on battery terminal
bulb in (running light): 15 ohms
bulb out (running light): 12.7 ohms

I didn't do this test for the blinker light although i did verify both lights were good by swapping with known good bulbs ( other side of car )

[ace123]

Also test above was for front of car.

[timmy2]

How many wires are terminated at the bottom of fuse 5? Colors of the wires as well.
Can you post a picture of the fuse box?
Your ohms are very low but it depends on the number of devices(lamps) tied to the circuit. Problem may be in rear lamp housing, front housing, wiring in between. Etc.
You need to isolate and test each wire connected to fuse 5 by separating them and testing to ground (neg) with lamps out of the socket.

[ace123]

Here is the fusebox. See fuse 5 for the issue.



I have done a couple of things. Both headlights work now. I had a bad high beam on one of them. I replaced it.

So the things that don't work are:

the left front marker lights
the left rear marker lights
the trunk light

The left headlight works both high beams and low beams.

All of them are on fuse 5. Fuse 5 blows when I turn the lights on.

Bently wiring says that it goes from the fuse to the headllight then to the marker lights.

Also, I noticed that on the light switch when I pull it to position one it lights the headlights. It is only supposed to light the marker lights. Position 2 does the same. Strange there.

[kidrock]

You stated that you've checked the bulb in the engine compartment, but have you checked the wires to it and the switch itself? I'm betting that the wires are toast, or the switch is toast. Disconnect your battery and pull that thing apart to study it, if you haven't done so already.

[ace123]

OK - I'll do that. It looks kinda rusty. I'll clean it out.

So what is a good way to test that switch? Should I test with the volt meter to see if there is voltage at the input wire (GR) before and after I clean things up?

Are there other tests that I should do before I put it back together?

I've been blowing a bunch of fuses because after I do something and then test , the 8A fuse blows if there are issues? Is there a way to save the fuses during the testing?

Thanks again!

[dshepp806]

Have you removed all bulbs within the relevant circuit THEN see if she blows that fuse? Next, as others have suggested (that is, assuming she DOES blow the fuse with all relevant bulbs removed), you'll have to ohm things out to determine where the shorted condition is occurring.

BEST,

Doyle

[ace123]

Good thought. When I take the ohm readings, where do I take it from - the positive of each light/switch to ground? Then look for a really high resistance or are ally low one?

I've been googling this week on techniques and haven't found too much on the ohm meter stuff with cars. I'll try again.

[ace123]

Good news guys! With your help, I'm finally on to something. I fixed the trunk lid light ( actually, I accodentally broke the housing and then taped it of after I verified that it worked with the bulb). Then I removed the mist of the bulbs from the circuit. Switched lights on and the fuse didn't blow. I cleaned the bulbs one by one and the leads. I started putting the bulbs back in and they are working. The rears lights are working and they werent before. I'm going to continue adding bulbs and checking.

[ace123]

Thanks everyone for all your help especially Timmy2, dshepp806 and kidrock. In summary, I'm at the point where the fuse doesn't blow and all the lights are good including the running lights, head lights, front and rear marker lights and engine deck light.

I think the root cause was the bad engine lid light and possibly some corrosion of the ground wire in the from marker light. I also had a bad headlight high beam which added to the confusion, but I don't know if it was related.

I ended up cleaning all the fuse connections and the ground wires that I could find. It seems like it helped as well. I learned a bunch about wiring diagrams and volt meters etc..

So thanks again you guys! I really appreciate it. I'll add my knowledge to the board one of these days when I'm good enough. I'm supporting Wayne by buying my parts from him. I bought a some stuff earlier and now I'm about to place my next order. I have to replace the engine light assembly that I broke and I'm going to do some other things like the deck lid shocks and sound proofing.

[timmy2]

Well done Ace, this forum is about people willing to help themselves with a few clues and direction from others.
Your knowledge level has increased dramatically since your first post in this thread and you are developing the confidence to take on more.

[kidrock]

Good job, Ace. For future reference, these cars seem a bit more finicky about their electrical systems than my old Fords, Chevys and Toyotas. When repairing or replacing, make absolutely sure that everything is super clean and tight. Don't cut any corners. Being a little obsessive/compulsive is not always a bad thing when tinkering or troubleshooting these cars.

[ace123]

Yep. Thanks again. I basically got a crash course in troubleshooting automotive electrical issues