Trouble shoot with me.. 500FF no longer working..

Alright guys so a little less than a year ago I installed Hella 500ff's on my Taco. the install went great and they worked awesome whenever I needed them.

Recently though- they are not working at all.
Today I started troubleshooting
Thought 1- check the fuses, checked them they looked fine but I had some spares and replaced them anyway- still not working.
Thought 2- check the grounds, checked the all the grounds (including the switch ground) they all seemed fine, undid them, cleaned the wires and the area around the grounds.. still nothing..
Thought 3- made sure that the "hot" wire was getting power from the battery- it is.
Thought 4- Check all the wires for damage and/or pinches.. everything seems fine.

So I am stumped.. any ideas?
I am thinking maybe the relay is bad? does that happen?

 

bump

 

so you have power and ground at the bulbs??

is this^^^ how it is wired

 

yes it is wired just like that

They have worked in the past, on demand then I stopped using them for a while went to turn them on a few days ago and nothing.

 

check the relay. Maybe tap it slightly.

 

Tried that, a few times then started giving it a few not so light taps.. nothing either way. I'm thinking the relay is dead.

 

if you can meter for power at the bulbs and its there when the switch is on and not when the switch is off then the relay is still good. if you dont have that ability then you could try to jumper out the relay with two pieces of wire go top to bottom and right to left(according to picture) if the relay is bad your lights will work. problem solved. if not i would try to disconnect the relay and meter all wires to ground with no power applied this will tell you if you have a short thus causing lights to not work.. just a thought.

 

do you have power and ground at the bulbs?

 

Did you check the bulbs? Maybe they're bad but it could be the relay.

 

Any update on this?

 

Maybe I can help.

I had the same issue late last year. I did everything you listed and even took a multimeter to all connections. I noticed I was getting some power, but not full power. So I checked all the connections.

The inline fuse (yellow wire with 20/25A fuse) did not connect well. It looked good, but wasn't getting a full connection. My guess was that it was melted a bit at the fuse.

So I never liked the glass-tube fuse connections. So I changed to the ATC fuse holder (what you normally see in the fuse box). I can't remember off the top of my head but maybe a 30 amp fuse or whatever the kit called for.

Long story short, I worked as soon as I flipped the switch. Never had a problem since.

Hope this helps.

 

I have not had a chance to take a volt meter to anything. Hopefully tomorrow I'll have the opportunity too.

That being said..

Hank I think this is what I am going to try tomorrow. I started looking at the fuses(glass ones in the white plastic/inline fuses) and it looks like the connections on each end are"ok" but not ideal.

 

Get your meter out and set it to measure for 12VDC.

With the light switch off, touch the negative (black) probe of the meter to the battery negative terminal, touch the positive (red) probe to pin 30 on the relay. There should be 12VDC (battery voltage) at all times. If not, you have a poor connection to the battery, a blown fuse, or a bad yellow wire (really unlikely).

Take a measurement with the negative probe on the battery negative and the positive on the relay's 86 terminal (green wire). With the switch off there should be no voltage. With the switch on there should be battery voltage. If not, check the 3 amp fuse and the connections on the white wire and green wire. If all that checks out, suspect the switch. You can test the switch by removing the white and green wires from the switch and connecting them together. If all else is okay, bypassing the switch in that manner will make the lights come on. If there is power when measuring from the negative battery terminal to the relays 86 terminal, then test with the probes on 86 and 85 to be sure of the relays ground connection.

Once you have power at terminal 30, and power at the relay's coil (pin 86 and 85), there should be power at terminal 87 (black probe to battery negative, red probe to terminal 87). If not, the relay is bad.

If you have power at terminal 87 and still no lights, the problem lies in the red wire between the relay and lights, the connections at either end, the light bulbs (unlikely to blow two at once), or the lights are not properly grounded.

I hope that's clear enough to follow. A $20 Craftsman meter from SEARS is a must have for anyone starting to do these types of projects. Swapping parts out is a potentially expensive way to troubleshoot. The meter will tell the story.

 

So you ever figure out your light issue?