Headlight Relays

[mrein3]

I did the headlight relay upgrade. However I'm having trouble when it is wet outside.

When it rains, and I'm running with the headlights on (required in MN), I have the low beams selected but the high beam relay "flickers" on and off.

This happened again Wednesday. This happened previously so I moved where I put the relays. The problem went away for a while but when I found myself diving in the rain Wednesday it started happening again.

Back home in the shop they continued to flicker until I pulled the 12V wire from the battery to the high beam relay.

I'm pretty sure the water is getting in the relay which is energizing the relay and with the lows on, the highs kick on and off.

So I have two questions:
1. Has anybody else experienced this with the relay upgrade?
2. What is the fix? Is there a better, more weather proof relay out there that I could purchase?

The relays I'm using are out of a bubble pack that I picked up at Checkers. They don't look very weather proof.

[Southedisto]

I used relays from a furd taurus, and they work great. The only thing I can think of would be to run a light coat of silicone around the opening in the relay, and make sure you use dielectric grease on the connections.

[kbs71]

Heres what you need.
40 amp Sealed Automotive Relay $US 7.95

Five terminal fully sealed automotive relay is capable of switching up to 40 amps. Fully sealed design is perfect for for exposure to the elements. The best solution for switching high amperage loads such as head lamps, auxilliary lamps, fog horns, motors, fans, window lifters, air conditioners, heated windows and mirrors, and a myriad of other equipment existing on vehicles today. Perfect for marine use. 12 volt coil.

R-40AS
Weight: 0.25 lbs
saw it here http://www.wiringproducts.com/?target=dept_35.html

[Musclerodz]

Originally Posted by mrein3

I did the headlight relay upgrade. However I'm having trouble when it is wet outside.

When it rains, and I'm running with the headlights on (required in MN), I have the low beams selected but the high beam relay "flickers" on and off.

This happened again Wednesday. This happened previously so I moved where I put the relays. The problem went away for a while but when I found myself diving in the rain Wednesday it started happening again.

Back home in the shop they continued to flicker until I pulled the 12V wire from the battery to the high beam relay.

I'm pretty sure the water is getting in the relay which is energizing the relay and with the lows on, the highs kick on and off.

So I have two questions:
1. Has anybody else experienced this with the relay upgrade?
2. What is the fix? Is there a better, more weather proof relay out there that I could purchase?

The relays I'm using are out of a bubble pack that I picked up at Checkers. They don't look very weather proof.

AAW make a specific headlight relay kit with OEM weatherpak connectors. Little pricey at $65, but should permanatley solve your problem. We have them but not online yet.

Mike

[Luvlegs]

I also did the relay install - I don't know if this might lead us both to the same solution - I have two problems - I replaced the inline shunts with an inline fuse. Truck starts and all fine, but if I turn on the headlights, the fuse blows - I've been told to try a 40A fuse (or 2 - 20's in parallel) - just haven't yet. I also saw a nice yellow truck on here where two inline fuse holders replaced the shunts - I assume it worked fine. When the truck sits overnight, the relays are apparently drawing down the battery - if unhooked, overnight, the battery is fine. I have them wired correctly (absolutely certain) - perhaps high humidity is enough to cause the relays to start "drawing" power? Hard to believe but it's an idea - same as when it rains.....

[Longhorn Man]

mrein3, try a new relay. Even the cheap overseas sweatshop built ones (you know, the ones wall mart sells) tend to hold up in the rain and humidity. Even in the salt and snow, I rarely see problems. It sounds more like the spring inside is weak/broken.

[mrein3]

Just in case anybody remembers this thread and was curious or was having similar problems...

What does Toby say, "Note to self..."

So I looked into my flickering headlight relays last night as I may be driving in wet conditions tonight. I picked up a new relay on the way home from work.

When I tried the headlights the high-beams were stuck on. No matter what I did with the dimmer switch the red indicator in the dash stayed lit and the high beams were on.

So I swapped the new relay in for the high beam side. That made them "flicker" again. You could hear the relay clicking on and off. I have a relay on the other fender that controls driving lights so I put that in place of the low beam relay. Still the same.

So I got the volt meter out. The dimmer switch works as it is supposed to so I ruled that out.

Some times you have to step back and think things through. There must be something common to everything that is causing the problem. I was starting to think it was the headlight switch which was new when I did the relay upgrade. Since it was new I wasn't too concerned that it was the problem. Besides it just sends current to the dimmer which switches between high and low and I already ruled that out.

So I started looking at the wiring again. I had the two relays hanging there, not attached to the fender. When I jiggled them, the relays clicked and headlights flicked. THEN I FOUND IT.

Stupid me. When I wired things up I ran a new wire from the driver's side headlight wires to the control side of the relay for both high and low. The wires for the passenger side headlight I simply pulled out of the headlight connector AND LEFT DANGLING. What was happening is the metal ends of the wires on that side were touching, sending current to both relays. The relays are stupid, you put 12V on the control side and it sends 12V off the battery to the light. So bouncing down the road they would touch together and make and break a circuit sending 12V to the control side on BOTH relays. I left the factory wires there because who knows, maybe some day it will be cool to have factory, dim, yellow headlights.

I taped the ends and solved the problem.

Note to self, do the complete job right the first time.

And this is still one of the best upgrades I've ever done to this truck.

[Rokcrln]

This is an up grade I plan on doing soon to Low Buck as well to our 67 Chevelle. Do you happpen to have a write up or a how-to link you could post? The only part I get fuzzy on is the relay hook up it self.

Thanks
Kevin
LFD Inc.

[mrein3]

Originally Posted by Rokcrln

This is an up grade I plan on doing soon to Low Buck as well to our 67 Chevelle. Do you happpen to have a write up or a how-to link you could post? The only part I get fuzzy on is the relay hook up it self.

Thanks
Kevin
LFD Inc.

Kevin,
Here is a good link with a wiring diagram.
http://67-72chevytrucks.com/vboard/s...threadid=92228
However, after reading and following some of your posts you seem pretty knowledgeable so I'll try to post how relays work so if you understand what I type, and wire it up then have problems, you'll have a shot at debugging it.

When you add a relay to power your lights, you turn your headlight switch into a relay controller. When you put 12V on the control wire of the relay, it closes a spring that connects a high current source with a high current demanding load.

In other words, the crummy old 12V wires that used to supply 10.5V to your headlights are good enough to "turn on" the relay.

First determine what wire is what on the back of the headlight. There are three. A ground, a 12V source for low beams, and a 12V source for high beams. Mark them.

Second determine where you want your relays to hang. You need one for high beams and one for lows. (This is where you post a picture of what you did and we all bow in awe of your fabricating skills). I simply made a sheetmetal plate, painted it body color, and pinched it between the core support and the RF fender.

To wire it up, you need to run a 10 or 12 gauge wire from the battery through a fuse (I used a circuit breaker) to the HOT side of the relay. Then make a wire from the HOT WHEN ON post of the relay to each headlight. You need to duplicate this for each relay.

Then run a wire from the low beam wire you marked in the first step to the control pin on the low beam relay. Duplicate this for the high beam relay.

Lastly you'll need to ground the relay. There is a pin on there for that. Connect it to a good ground.

If you have a 5 pin relay, the middle pin is for an item that gets 12V when the control wire is not hot. However on my system I simply put a female connector on there with no wire attached to prevent any light shows under the hood.

That is about it. Again, your existing headlight wiring is used to turn on either the low beam or high beam relays. Those relays direct power direct from the battery (through a fuse) to the headlights.

Oh. And if I ever get around to working on them again, both my Chevelles are getting this upgrade.

[shifty]

i used the duoube-relay setup from a 92-94 Dodge Duster/Shadow/Summit/Spirit/etc. You'll find them with fairly water proof plugs mounted to the strut tower on the inner fender (pointing forward in the car).

[BobbyK]

Here what I did.
It'a alot of wires in a small space.

[Sport/Truck]

Originally Posted by BobbyK

Here what I did.
It'a alot of wires in a small space.

The above picture looks good, but I would like to see a fuse for protection. I don’t think I would put in on just the main power wire either. The main would need to be large enough to carry the load of everything. And possibly wouldn’t protect a smaller wire from burning up. A good solution would be to use fusible links or fuses between each relay.
s/t

[Rokcrln]

Yep thas will happen in th enext week or two as time allows. Thanks for all the info and pics but what I need is th ediagram of just the relay hook up it self. I have been using relay's for years in our off road vehicals but I had a buddy alway's point to the right blade for hook up so I never payed close enough attention to how it went I guess maybe I should check the link you posted as well

Kevin
LFD Inc.

See I knew I should have looked a little more. Here are two very simple to follow (just what I needed) diagrams I found in other links.

[mrein3]

Originally Posted by Rokcrln

snip
Thanks for all the info and pics but what I need is th ediagram of just the relay hook up it self.
snip

One more picture. The back of the bubble pack of the one I just bought was still high in the shop trash can.
I used the outside "87". The inside one I simply put an empty female connector on.

BobbyK - Those relay plugs really make for a cleaner install. I need to buy a few.

[Already Gone]

I'm no genius with this stuff but took the suggestion from Texas Firefighter and got my relays from a late 80's Dodge Caravan at the wrecking yad and paid $3.00 for them. They are sealed and I installed them near the horns on the rad support doing the install myself last summer. I've driven in some major rain storms since then and havent had any kind of problem with the lights at all. I also installed Tri-Bars at the same time and I'm sure between the tri-Bars and the relay setup my lights are 500% brighter.

[shifty]

Originally Posted by Sport/Truck

A good solution would be to use fusible links or fuses between each relay.
s/t

that would be a bad solution. what happens if you short out while driving down a windy road in the dark? DOH! There goes your headlights, and your ass is going off in the woods.

ALWAYS always always use breakers and NOT fusible links when dealing with headlights and other safety equipment.

[Sport/Truck]

Originally Posted by shifty

that would be a bad solution. what happens if you short out while driving down a windy road in the dark? DOH! There goes your headlights, and your ass is going off in the woods.

ALWAYS always always use breakers and NOT fusible links when dealing with headlights and other safety equipment.

No, I said fusible links to each relay with a fuse rated for the load rating of the feed wire (assuming the wire is sized properly for the load). He won’t blow everything at once with that setup. What he has now (from what we can see) is exactly what you described dangerous!
But a self resetting circuit breaker can replace the main fuse I mentioned, but the smaller wires still needs protection too. Or you can potentially have a toaster wire and burn down the truck.
Agree?
s/t
I should say this bit of caution ~ One would need to read the specs for the fusible link and compare it to a regular fuse and size accordingly. I was merely suggesting something that can keep the clean looks of the wiring.

[shifty]

Agreed.

Personally, I would try to find a ditribution block that had a breaker or series of breakers built in.

[Sport/Truck]

We use a distribution block at work; they also have LEDs & are sweet, but a little bulky and also not rated for outdoor use. A good distribution block would be a great idea for several accessories.
For now I think I’m going to use the method LFD has listed above. Seems simple enough for just lights IMO.
s/t

[BobbyK]

That is a seconadry distribution block you see in the pic.

The large red wire(8g),comes from the primary Distribution block I have on my firewall.
The main power feed to the secondary distribution block is protected with a fusable link.

Each headlight relay is fed from the secondary distribution block.Both relay's have fusable links (light blue wires in my pic)




The blue relay for the driving lights has a replaceable "blade type" fuse built into the top of the relay.


I've had an electrical fire once before...I now protect all my major circuits with fusable links and the minor circuits with fuses.





.

[Sport/Truck]

Cool, sounds like its done right. Sorry to hear about your fire.
s/t