Hi. My first post here, I hope it's the right place.

I got my son a 96 model Ford explorer 4x4 v6.

The blinkers and hazard lights wouldn't work so I went to get a blinker flasher (relay?). Once installed, all four blinkers and the hazard lights worked.

We tested hazard lights first and they worked. Then driver side blinkers, front and rear were fine. Then we tried the passenger side blinkers. At first, only the front passenger blinked so I hit the rear one and it came on for a few blinks until he switched to the driver side once again.

Finally I told him to try the passenger side again and the rear wouldn't blink, but the engine was just slightly surging in sync with the front blinker flash. The surging lasted about 15 seconds and then all blinkers and the hazards stopped working completely.

Fwiw.. The rear passenger blinker plastic is busted and has clear colored tape on it. I wondered if water in the socked would burn out the relay but I'd think a fuse would open first.

Any help is much appreciated.

 

The flasher module should not be susceptible to a shorted bulb socket, if that were an issue. But, it appears to be a solid state flasher and as such, would be susceptible to a low voltage condition. The surge you mention sounds like it might be the engine trying to compensate for the current draw of the lights, and maybe the alternator or the battery is not able to keep up at an idle.

My suggestion would be to start by measuring the system voltage with the engine running and hazard lights on. If the charging system is not maintaining at least 12.5 volts, something is not right. If you get a decent voltage reading at idle, shut the engine off and see how well the battery can sustain the lights If the voltage drops below something like 11 volts every time the bulbs turn on, the battery would seem to be getting weak and should be changed. In this scenario, a new battery could solve the turn signal issue.

If the charging system is fine and the battery is strong, the surging idle in sync with the lights would indicate either a grounding issue or a short circuit that you will probably need a wiring diagram to track down.

-Rod

 

Thank you, Rod, for your help.

I probably should have mentioned that I also bought a brand new battery at the same time I bought the blinker flasher.

Also, there was no engine surging while using the hazard lights or the driver side turn signal lights, although I can't remember how the passenger rear signal acted with the hazards on, I thought it was working fine.

The surging only happened while trying the passenger side turn signal.

I seem to remember a faint glow in the rear passenger side turn signal when it was doing the surging. It seemed like power was being drained upon each blink, causing the low point of the surge. Which I guess would be more of a "dip" than a surge.

I will try it again tomorrow and keep you updated. I'll buy another blinker flasher if I need to as it was a cheap part.

Thanks again!

 

Might be interesting to see if there is any parasitic draw when everything is shut down, too.

 

The faint glow is often indicative of a grounding issue.... The bulb doesn't have a good clean ground so it looks for the next lowest resistance path to ground which usually results in a leakage path through another device, hence the limited current and faint light.

-Rod

 

update..

Tl:dr.. Hazard lights keep blowing the hazard fuse, and passenger side turn signal also blows hazard fuse.


Finally had a chance to go get another flasher.

Started off by taking the rear tail light assembly completely out, to take it out of the equation incase the problem was within the broken, water filled assembly.

I installed the new flasher and tried the hazards and blinkers didn't work. Started the engine and still nothing worked.

Thats when I decided to break out the owners manual and look for a fuse block diagram. Omg.. hazard lights fuse was blown.. derp.
Which tells me that the first flasher I bought was probably still good, and the original might have been good too. ahh well.

note... hazard light and turn signal fuses are separate.

So I noticed the hazard fuse was supposed to be a 15a fuse, but it had a 30a installed that was blown.

I went through all the fuses to see if any more were blown and if they were sized correctly. There were a few that were over sized but no others were blown.

I then went to the parts store and bought what I needed, which was just 3, 15a fuses. I bought a 5 or 6 pack.

When I returned home, I installed the fuses where they needed to be. I turned the key on (not the engine) and tried the hazards. The 15a hazard fuse blew immediately.

I turned the key off and put a new 15a fuse in the hazard light slot. I then turned the key back on and tried the driver side turn signal and they worked flawlessly. Then I tried the passenger side turn signal and the hazard fuse blew once again.

One more note.. neither turn signal will work if the hazard fuse is blown.

Edit... I did use my volt meter across the hazard fuse slot and got 11v with the engine off. not sure that helps tho since current blows a fuse, not voltage.

 

Im no expert but the way it looks, I must be going to ground when it tries to light up one/both of the passenger side blinkers. Because the driver side blinkers work just fine.

But why would it blow the hazard fuse and not the turn signal fuse?

 

Ok, I took the steering column wrap off, and took the blinker mechanism off, which has the hazard button on top of it.

I turned the ignition on and used my meter to find the hot wire. The only one I could find was 5 volts, so I called that the hot.

I took the blinker switch inside the house and turned on the driver side blinker. I had my meter set to continuity testing and put a lead on the prong that went to the slot I had 5 volts on in the harness found in the column. I put the other lead on every other prong in the switch until I had continuity. Once I found it, I switched the passenger blinker on and then found the prong that had continuity to the 5 volt prong.

Now I feel like I know which slots in the wire harness go to the blinkers.

I went back outside and tested the passenger and driver side blinker slots to the frame of the truck with meter set to continuity. I got nothing.

At this point Im wondering it the switch assembly itself is the problem but Im not sure how to test it.

I did find the slot that is continuous to the frame. So I tested the blinker prongs to the prong that I think is the ground but still I got nothing. That makes me think the switch is good.

Upon inspecting the wires coming from the back of the flasher module I noticed that the blue wire was showing some copper and it looked like it had been squeezed down. I can see it being a problem if it was touching metal, and maybe it was at one point, but not on the last 2 times i tested and blew fuses.

 

Sorry to spam this thread but I think I may be onto something.

When I turn the key or engine on, constant voltage is fed to the blinker switch on the column, but the fuse holds. So the ground short can't be on the "line" side of the switch.

When I turn on the blinker switch, it feeds the flasher module with constant voltage. The flasher module intermittently sends voltage to the blinkers.

The other night, the engine would "dip" in sync with the blinkers lighting up.

This tends to tell me that the ground short is happening when the flasher module sends voltage out. Meaning that the problem is somewhere between the flasher module and the passender side blinker lights.

All I need now is a wiring schematic to trace out the wire.

Does this make sense?

 

Way above my paygrade. Wish could help.

 

I have the factory wiring diagram for the 1996 Explorer turn signals. If you'd like a PDF of the diagrams, send me a Private Message. Please include the year and model of the Explorer, information you're requesting, and an e-mail address to send the PDFs to. The diagram is 3 pages long.

-Rod

 

Thanks for the offer! Unfortunately I can't send PM's yet as I haven't been a member for 10 days. I do have the required post count though. Ill PM you as soon as I can. In the meantime, check your direct messages please.

 

Will do, I'll send the files this evening.

-Rod

 

Thanks for the documents, Rod. Hopefully I've found the problem. I used the switch test guide and found that the rear hazard lights had an open circuit where it should have been closed. I'm going to the junk yard tomorrow night to get another switch and I'll update with my findings. Here's the test that failed. imgur: the simple image sharer

 

Did you stop when you got to that point, or did you continue on to test the rest of the positions?

If you tested everything and that's the only discontinuity that you found, that should only impact the hazard lights, not the turn signals as well. Also, if that's an open circuit it should not cause the fuse to blow. You might want to also check the wiring from the MFS to the lights. If you have a fuse-protected test lead you could try feeding power to the LG wire to see if both rear taillights light up. You could then try applying power to the W/LB wire for right front turn signal and LG/W wire for left front turn signal to see if any of these circuit cause the fused test lead to blow the fuse.

-Rod