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Quick questions before I drop almost $300 on a hiBeam/lowBeam/Washer/Headlight Washer steering column switch in my '89 Turbo. Here's what I know:
Passenger side low beam is shorting #23 fuse. High beam is fine on passenger side. Power is getting to the high beam. None to low. So that would rule out a short between the fuse and the bulb. This would also rule out a broken wire as well. If it was a broken wire, the fuse wouldn't be blowing.
Tested the "Complimentary Driving Light" relay and it seems to fine. It clicks, and resistance checks out.
If there was a short in the ground on he passenger side, wouldn't the high beam blow a fuse as well?
That puts the short closer to the stalk, in the switch, I'm deducing. If my electrical logic is incorrect anywhere, please let me know. Many thanks.
The stalk switch is common to both head lights, and not part of your issue.
Check the area of wire movement around the light bucket for your short. Use meter or test light and move the wires around the bucket to see if the short is intermittent. Do disconnect the headlight plug and verify the plug is not contaminated. Check for the short with the light unplugged.
The stalk switch is common to both head lights, and not part of your issue.
Check the area of wire movement around the light bucket for your short. Use meter or test light and move the wires around the bucket to see if the short is intermittent. Do disconnect the headlight plug and verify the plug is not contaminated. Check for the short with the light unplugged.
Alan
My intuition tells me the same thing. If it were the switch, then both low beams would be out. From what I can see, in the whole area, after stripping back the plastic covering, no wires are touching or broken. And as I said, power does reach the passenger high beam.
But, what confuses me though is, if the short was close to the bucket, woudn't the passenger high beam blow a fuse as well?
UPDATE: Still searching and learning. Thanks for all the advice everyone. Will report back. Back to focusing around the headlight again. Not the switch. Part of my challenge is understanding the concept of electricity and how it flows.
Last edited by kevinr1247; 11-17-2015 at 11:59 PM.
The high beam has it's own conductor. Consider the low beam is the most used, and the outer jacket for the low beam will be heat hardened, as is the ground conductor. Unless there is obvious damage to the outer poly covering in some other area. Check the full length from the headlight to the fuse box.
Try moving the outer sleeve, in in the bucket area, to see if you can break the short, while using a test light or ohm-meter.
Quick question: If there was ground short between the headlight and the grounding point up in the front (as indicated on the wiring diagram in red), wouldn't that also blow the fuse for the passenger high beam, as well as the low beam? It seemingly would also blow fuses for the other loads connected to that ground point too. Still at it.
UPDATE: Doing my best to rule out the $300 column switch and understand what's going on. Now I think there must be a fault in the yellow wire somewhere, as per many suggestions. But I can see no evidence that a wire is broken or touching metal. Hmmm. How much is a front wiring harness? It's more than just broken wire because the fuse is blowing. Forging ahead. All advice appreciated.
Last edited by kevinr1247; 11-21-2015 at 03:29 PM.
When you unplug the lamp and remove the fuse, you have a ground on the load side of the fuse connection? Did you try another headlight connected to the plug?
You have called the problem a short, but more amperage draw from a failed lamp will also trip the fuse. Normally, lamps fail open circuit, but check the easy solutions.
The reasonable place is the moving wire section near the lamp bucket. Or a pinched section of wire. Done any other work under the hood prior to this problem starting?
When you unplug the lamp and remove the fuse, you have a ground on the load side of the fuse connection? Did you try another headlight connected to the plug? YES
You have called the problem a short, but more amperage draw from a failed lamp will also trip the fuse. Normally, lamps fail open circuit, but check the easy solutions. Fuse blows without a load.
The reasonable place is the moving wire section near the lamp bucket. Or a pinched section of wire. Done any other work under the hood prior to this problem starting? YES, the timing best was done a few months back.
I made a little video of what I'm looking at. Still searching. The fuse blows without a load (a headlight connected), as you can see in the video. All I had to do was flip the low beam switch and the fuse blows. What other tests can I do to narrow down the issue?
EDIT: Forgot to add this wiring diagram for the lights. Stitched it together from the PDF. You can zoom in on it. Hope you find it useful.
The best approach is to divide and conquer. Find the middle of the harness for the light, open the cover beige jacket and nip the correct colored power wire. Determine which half retains the short.
At that point, you may be able to pull the wire out of the protective jacket. Do connect a pull string, to help pull in a new conductor.
You should be able to do very little damage to the outer protective jacket.
If the wire will not pull from the jacket, it may be bonded to the ground, try to pull both. Or open the beige jacket.
If the jacket had some traumatic event, pinched, there should be subtle marks on the jacket.
If all this does not work, put a patch over the headlight with the fake eyelashes, and start a new fad.
The best approach is to divide and conquer. Find the middle of the harness for the light, open the cover beige jacket and nip the correct colored power wire. Determine which half retains the short.
How easy is it to access the wire harness? I think I know the answer, but I thought I'd just throw that out there. It sounds like a royal PITA just to get at it.
The wiring harness runs around the engine compartment. Pick a convenient place to cut. And hide the cut, after the job is done.
Another alternative to consider, is that the ground point for the headlight is on the front frame rail, outside. Remove all the grounds at that point to see if the short goes away. If so figure out which ground is to the light. Also this narrows the location to the last 2-3' before the light.
An alternate ground can be run, without disturbing the wiring harness.
Last edited by Alan 91 C2; 11-20-2015 at 09:49 PM.
The wiring harness runs around the engine compartment. Pick a convenient place to cut. And hide the cut, after the job is done.
Another alternative to consider, is that the ground point for the headlight is on the front frame rail, outside. Remove all the grounds at that point to see if the short goes away. If so figure out which ground is to the light. Also this narrows the location to the last 2-3' before the light.
An alternate ground can be run, without disturbing the wiring harness.
Thanks again for the advice. It'll be nice when I finally get this worked out.
On the wiring diagram there is a reference to the "Front End Wiring Harness." Is the bar that all the wires cross (that I have marked) a plug by chance? If so where is it in the engine compartment? Curious.
The bar is a reference to the enclosure for the fuse box. The wire from the fuse goes to the plug on the bottom of the fuse box, and on directly to the headlight connector. The apha numeric designation after the bar is the plug and pin into the bottom of the fuse box.
Had to pull the intercooler cover panel off to get a little more access to the harness. Split the harness with a blade to get access to the headlight wires. The gap you see in the sheathing is literally how I found it.
You know they make electrical probes that basically stick a needle onto the wire to check with a millimeter so you don't have to damage the wire sheath and make the bare wire venerable to the elements. That wire needs to be cut and have heat shrink installed over it with a soldered connection for years of trouble fee issues. Electrical tape will fall off over a little bit of time.
I thing the shop manual has a continuity test for the headlight/turn switch.
11-17-2015, 05:29 AM
Short blowing #23 fuse, headlight
