Relay Help

MikeyZR5 · Post by **MikeyZR5** » Sat Jun 14, 2003 4:11 pm

I am going to hook up my fogs and I forgot what goes where on the relay, can someone help me out!?

Thanks alot!!!

MikeyZR5 · Post by **MikeyZR5** » Sat Jun 14, 2003 7:31 pm

OK...I did some good ole research and found this document online...from KC foglight installations:

Just in case someone needs it for future reference.

Post by **HenryJ** » Sun Jun 22, 2003 10:31 am

Thanks for posting that pic

I've installed a million relays and i still don't have that memorized

F9K9 · Post by **F9K9** » Sat May 06, 2006 12:57 pm

Okay, I noticed that my KC dayliters have joined the ranks of some of my pet ducks and died. I figured it was in my switch because of the many times I have removed the dash trim for the e-fan problems. I checked their + and - wires and they were good along with the fuse. The ignition on + wire was good but, I went ahead pulled the battery, it's shelf, coolant recovery tank to check all the wires, removed all wire connectors and soldered every thing up and finished with heat shrink tubing. No Da*n lights! It's got to be the KC supplied relay. Does anyone know of a good relay available in auto parts stores? Everything I have seen looks cheap and not suited for exterior (engine bay) conditions. I may as well buy two because my aux reverse lights had a suicide pact with the KCs

Post by **HenryJ** » Sat May 06, 2006 1:27 pm

I usually just grab a handful at the salvage yard. Heck you can get a whole bag full of relays and fuses for $5. Barring that, any auto parts store relay should suffice.

I have not seen a huge difference in the inner workings of the standard DPST relays. Any of them will work fine in an engine compartment. If they get full of water drain them, dry them and they will usually function again. This is why it is important to locate them with the terminals down.

Pop the cover off of your old relay and see what the problem was. If it is toasted then perhaps you need to separate the load and use two relays. If it has water damage, relocate, reorient, and protect the new one.

I see the images above are no longer valid

That is why I prefer to link images from "our" gallery. At least then we can count on them being available for the long term.

Here is a diagram:

#85 , green positive relay activate
#86 , black negative relay activate
#30 , yellow supply
#87 , white Normally open to accessory
#87a , black Normally closed to accessory

F9K9 · Post by **F9K9** » Sat May 06, 2006 1:44 pm

I really wasn't worried about the price of relays but, this one in question, is a hassle to get to and test, I wanted something a little more reliable. Since it is from a "good" supplier and under a year old. I was hoping to make things a little more "bullet proof" given my track record.

I guess one must visibly inspect a vehicle's functions like a pilot does before "take off" each and every time. We have been lulled into expecting things to work when they should.

Post by **HenryJ** » Sat May 06, 2006 1:52 pm

You can definately get some "bullet proof" relays if you want to stray from the standard automotive DPST relay.
Check Jameco and other electrical suppliers. There are thousands to choose from.

I stick with the standard automotive relays because they are easily replaceable and ever car out there has one I can steal in a pinch.
Perhaps relocation to a more convenient place would be a good course of action?

F9K9 · Post by **F9K9** » Sat May 06, 2006 2:09 pm

HenryJ wrote:................................Perhaps relocation to a more convenient place would be a good course of action?

I have considered the location but, the engine bay is so darn "busy" fashion wise, I was having difficulty deciding how to color coordinate.

Post by **HenryJ** » Sat May 06, 2006 2:28 pm

Word on the street is that black is the "in color", all the relays are wearing it this year

F9K9 · Post by **F9K9** » Sat May 06, 2006 3:45 pm

HenryJ wrote:Word on the street is that black is the "in color", all the relays are wearing it this year

Is that the official word? Blessed for all occasions after Easter?

top_sgt · Post by **top_sgt** » Sat May 06, 2006 4:15 pm

f9k9 wrote:
HenryJ wrote:Word on the street is that black is the "in color", all the relays are wearing it this year
Is that the official word? Blessed for all occasions after Easter?

actually.......year round....provided you are north of the equator...which we are!!!!

rlrnr53 · Post by **rlrnr53** » Sun May 07, 2006 3:31 am

I have used relays from NAPA in the past, but the last few have been made in China, and haven't been too reliable, so beware

F9K9 · Post by **F9K9** » Sun May 07, 2006 4:37 am

rlrnr53 wrote:I have used relays from NAPA in the past, but the last few have been made in China, and haven't been too reliable, so beware

Thanks for the "heads up". I am getting a little tired of stuff being made in China. I've even purchased some craftsman items recently that was made in China. I admit that there has been a slight gap in my craftsman purchases (like 3 decades) so, it was a shock to me

F9K9 · Post by **F9K9** » Sun May 07, 2006 12:27 pm

Well, a Borg-Warner relay and some gold plated female connectors with some dielectric grease coating the connections got one daylighter up and running (I knew the other wasn't going to light up from my troubleshooting yesterday). Will have to wait out this rain before tearing into the non working light to toss a meter on it. Might be the connections behind the grill. I need to go in there anyway due to the quad mod joining the suicide pact with all the other aux relays.

HJ, are those aftermarket back up light bulbs holding up for you? Looks like I have one out already. Noticed it when I checked my aux BU lights yesterday.

F9K9 · Post by **F9K9** » Sun Oct 22, 2006 5:29 am

Okay, I was fiddling around with the aux backup lights last night trying to get one to work. I apparently grounded a hot wire and the good one went out. I figured it was a fuse blown but, it's not. Can a relay be blown in this manner?

Post by **HenryJ** » Sun Oct 22, 2006 5:46 am

f9k9 wrote:...I figured it was a fuse blown but, it's not. Can a relay be blown in this manner?

Yes.

The relay is a tiny electro magnet. This is wire wrapped around a piece of metal and energized it creates a magnetic field. This magnets core is one side of the connection through the relay. The other side is a metal contact that is drawn down when the magnet is energized. When the two touch the circuit is completed and power can flow through.

That is kind of a simplistic explanation.

If the tiny wire for the coil was shorted , it can easily be burned out. This would have the relay fail to energize.
You can test this with a multimeter. Check the continuity between #85 and #86 If there is no continuity, the wire has been broken and the magnet will not energize.

You can also pop the plastic cover off the relay and check out the relay for damage. Another possible cause would be fouled contacts. While possible, this would be unusual. The contacts in this case rarely see very high voltages and therefore don't foul like the old points distributors used to.

Anyway...you have some things to check now

Not a bad idea to keep a spare relay in the rig. They do fail like fuses , although not as often. They are a good safeguard in that aspect. Better than burning down the truck.

F9K9 · Post by **F9K9** » Sun Oct 22, 2006 6:17 am

Thanks, Brule! I'll pick up 2 this morning when I get My Water Wetter

Post by **Walt** » Sun Oct 22, 2006 10:12 am

I just fixed mine. they've been out for a month or so. I've gone through seven relays, from the KC one, to cheap autozone relays, to the more expensive bosch relays. I finally got frustrated and dug up an old PAC-200 I had stored from an audio install in a previous vehicle. I can hear the relay turn on and off from inside the cab with the engine running.

Its as big as a soda can and weighs over two pounds. I doubt I'll have to worry about it anytime soon.

F9K9 · Post by **F9K9** » Sun Oct 22, 2006 10:22 am

It was the fuse after all. Taught me not to just eye ball a fuse instead of breaking out the meter

BTW, Walt, I melted my 4th set of KC light covers last night

Post by **Walt** » Sun Oct 22, 2006 10:34 am

f9k9 wrote:It was the fuse after all. Taught me not to just eye ball a fuse instead of breaking out the meter

BTW, Walt, I melted my 4th set of KC light covers last night

Which ones? the plastic yellow ones? You leave them on to long? I just got a pair of old black generic 6 inch lights. I may put the Wagner 150 watt bulbs in them.

F9K9 · Post by **F9K9** » Sun Oct 22, 2006 11:56 am

I gave you the yellow ones.

It's this style

It's usually RELAY related but, yesterday I pulled my coolant recovery tank (the relay was mounted to one of the tank's fasteners) while changing my coolant and it must of hit a battery post and blew the fuse. I replaced the fuse and pulled a cover off the light to check it. I put the cover back on intending to immediately turn the switch off. Something distracted me.

F9K9 · Post by **F9K9** » Fri Jan 05, 2007 7:34 pm

HenryJ wrote: Here is a diagram:

#85 , green positive relay activate
#86 , black negative relay activate
#30 , yellow supply
#87 , white Normally open to accessory
#87a , black Normally closed to accessory

OK Brule, I know you might not even reply to this but, I am simply not retaining exactly how this works. I know that I am electrically challenged and have told you many times that I am an electrical moron

You have to try to explain this in the simplest of terms to me.

#30 is a constant hot to the relay?
#85 would be from a switch supplying 12 v to the relay to activate something like a light?

#87 is wired to the light's positive wire?

If, those 3 are correct, which I doubt, what is wired to the relay to ground it?

All I want is to flip a switch that sends 12 v to the relay and it turns on a light.

Post by **HenryJ** » Fri Jan 05, 2007 7:53 pm

I go back to that same picture and explanation every time I do a relay too.

You have them all correct. You just need to ground #86.

If you look at the little diagram to the left side you see #85 and #86. The are positive and negative for that little coil. It is an electromagnet that pulls the contacts closed for the relay. Either one can be positive and still work. as long as one is positive and the other is negative it will work.

F9K9 · Post by **F9K9** » Sat Jan 06, 2007 4:38 am

Thanks again! I've got 2 of the 3 wired up now.

F9K9 · Post by **F9K9** » Sat Jan 06, 2007 7:52 am

Brule or Walt, hopefully one last question for you.

I am putting a 30 A fuse at the battery and that wire will be connected to the lower connector block in the first photo. Do I need another inline fuse for each pair of lights and if so, where? The unattached red wires coming out of the relays are to each pair of lights The unattached blue wires will be connected to the switches. Thanks!

Post by **HenryJ** » Sat Jan 06, 2007 8:26 am

The one fuse at the battery for the wire supplying the terminal block will protect the system. If you have an individual lamp with a problem it might not be enough to blow that fuse given the distance.
The relays would burn out in this case. They will protect the wiring and prevent a fire. You can protect them by adding a fuse between them and each of the lights.

A fuse inline between the relay and the lights would not be a bad idea.

Would I add three more fuses? Probably not. I would be comfortable with only the one fuse for the supply at the battery. I see it as less places to have to try and find a problem.
That may not be the best way. It may not even be the "correct way". It will work and should be safe enough. Remember K.I.S.S. The more places for something to go wrong the better chances something will.

Post by **Walt** » Sat Jan 06, 2007 8:44 am

I agree with Brule. A fuse at the battery is a must. You want it as close as possible to the battery. If you really want to add individual fuses, there's nothing wrong with that, but the aforementioned K.I.S.S. principle should be considered.

Are you running the positive or ground trigger inside the cab for the on/off switch?

F9K9 · Post by **F9K9** » Sat Jan 06, 2007 10:35 am

Walt wrote:...................Are you running the positive or ground trigger inside the cab for the on/off switch?

I "THINK" a positive but, nothing is set in stone yet

all the wires are run to their meeting place but, nothing is connected yet. Cab is still torn apart. Inline fuse to each light is out of the question now unless I start from scratch. Lights are wired in pairs.

The switches have an LED and three prongs

Post by **HenryJ** » Sun Nov 01, 2009 8:29 pm

Relay Basics

F9K9 · Post by **F9K9** » Sun Nov 01, 2009 9:04 pm

22 months later I get new info? Whew, am glad I wasn't hanging onto a cliff face.

fallvitals · Post by **fallvitals** » Mon Nov 02, 2009 9:19 am

Ah be nice, Brule probably just now got his dial up to connect again