Buzzing when headlights on

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jfnall

jfnall

10 Year 15 Year
Joined
Feb 9, 2007
Threads
106
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1,074
Location
Nixa, MO
Website
www.whiteriverlawncare.com
There is a buzz from around the left lower panel under or around fuse panel. Headlights off it goes away.

Ideas? Maybe a headlight relay? Any potential damage or will the lights just not work?
 
headlight relay for sure. Mine does it with the wiper. when they wipe the relay is loud.
 
Well... Replaced headlight relay. No more buzzing. But also no more headlights. I also checked the fuses and they seemto be fine as well. I'm guessing it's a pretty slim chance both bulbs went out at the same time.

Chance a relay from Autozone is bad out of the box?

I guess i just better get home by dark. Any other ideas to check? Is there another relay under there that is tied to the lights ? This is an 85 fj60
 
jfnall said:
Chance a relay from Autozone is bad out of the box?
Click to expand...

There's a good chance of that. :)

Maybe other stuff too. Double-check the wiring diagram (it's in the chassis and body manual, which you can find by clicking the Tech Links link at the very top of the page) to see if there's anything else down there, but my guess is the relay is either bad or hooked up wrong. Both theories are easy to test.
 
Headlight Washers?

I was wondering about the headlight washers. Don't they come one when the head lights are on and the windshield washer is used? Could there be some cross up there? Let us in on the resolution of your problem. Good luck
 
Well, still no headlights.

I have replaced the Autozone relay with an O'Reilly relay, and gotten the same result of No Lights. I have a Toyota relay on the way, but I am guessing it won't change things.

The relay I changed was a square plastic housing relay with 4 prongs. Also changed a metal round 4 prong relay. Still no headlights. It's tough to wire test these since all the wires are tricky to access. I am going to take out the panel this weekend to access the wires to see what's happening.

any ideas? Everything else on the truck seems to work. All taillights, parking lights, blinkers work. Dome lights work. Starts fine.

I will get some closer pics and OE part numbers on what I have replaced.
jeff
 
Part Numbers for relays

here are the part numbers I replaced with new relays.

the 4-pin square relay is the closest to the firewall (the bottom right in the picture).
90987-02006

also replaced the metal round 4 pin beside it, just up in the picture. the brighter brass colored relay.

I have also checked the fuses by the left knee. The Headlamp R and L are both good fuses, and neither have any power coming to them.

the other 2 relays are for the blower and heater best i can tell, am I'm not sure what the large green box is, flasher? not sure. the parts breakdown is hard to decipher with the way things are blown apart in the pic.

next idea to try?
IMG_0961.webp
 

Attachments

thanks for that link. I will dig in with the meter this weekend.

I do have a Toyota relay that is on the way.

One thing I forgot to mention..... while I was doing this relay in out business. I had the headlight switch in the on position when I plugged the relay in. I didn't get it all the way in and realized it. Some electric parts may have touched, I pulled it back out and turned off the switch. then plugged it in and tried the lights.... no lights.

could this have burned out the bulbs? test light will let me know if I have power at the bulb

thanks. will let you know what I come up with.
jeff
 
jfnall said:
thanks for that link. I will dig in with the meter this weekend.

I do have a Toyota relay that is on the way.

One thing I forgot to mention..... while I was doing this relay in out business. I had the headlight switch in the on position when I plugged the relay in. I didn't get it all the way in and realized it. Some electric parts may have touched, I pulled it back out and turned off the switch. then plugged it in and tried the lights.... no lights.

could this have burned out the bulbs? test light will let me know if I have power at the bulb

thanks. will let you know what I come up with.
jeff
Click to expand...

There should be a fuse for the lights so it shouldn't have blown the lights out.

I will say when I bought a bunch of relays at auto zone to hook up for misc. things on an engine swap, I followed the diagrams on the relay and nothing happened. My fuel pump wouldn't turn on and the ignition wouldn't kick the starter over. I went and bought new ones at checker, hooked them up according to the relay diagrams and same thing, nothing worked. I ended up just testing different wiring setups on the relay until all the sudden the cheap auto zone relays started working. Not saying this is your problem, but I wouldn't be surprised. They were universal 4 prong 30 amp relays I believe.
 
i got it fixed. I took off the relay panel so I could get to the wires to test them. I had no power at all coming into the headlight relay. The trusty FSM showed the only break in the line back to the battery was at the green plug near the battery with the fuseable links. that tested it had power coming out. so......

in a previous "upgrade" I added a battery disconnect key. In order to do this, I needed longer wires on a few wires in the OEM bundle. Quite a while back, I did this. I guess the vibration had caused one of the wire crimps to let go. Lesson learned. Don't used the cheap blue connectors from the parts store. Always get the kind that are heat shrinkable. The shrink part helps hold the wire, as well as the crimped part. I must have run 1 crimp short when I did this, because it was the only one of the bunch that was the cheap connector. All the others were good and strong.

Problem fixed. I know how to fix things because I have broken it 4 times previously.

Went ahead and changed out both headlamps since I had them out testing wires. Everything is much brighter now. I am legal to drive at night too.

The parking lamp relay (3 prong) is the metal relay just to the left of the square headlight relay. This seems to get hotter than I would like. Actually pretty hot to the touch after just a few minutes of the headlight switch being on. It this normal? or do these relays go bad with age and tend to get hot like this? might change it just to see.

btw, it turns out the OEM headlight relay wasn't bad at all. the clicking I guess was the power coming on and off from the bad connector by the battery. I put the original Toyota relay back in and will keep the ordered Toyota relay in the glove box for spare. might be in there for another 25 years . all the aftermarket stuff is getting me a refund.

thanks for the advice.
jeff
 
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