M-series flasher relay - civvy conversion how-to

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clinto

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So, everyone is familiar with the standard M-series flasher relay? 2 bolts, 3 pin cannon connector, attaches to the drivers side firewall or inner fender, depending on model.

This one:
turn-signal-flasher-control-unit-24-volt-11613631-13.jpg


How many of you realize that the current replacements are absolutely worthless trash? Well, they are! I’ll bet in the last 5 years I’ve had to buy 30 of them. Easily 50% of the deuces I’ve gotten from GL needed one.


And the worst part is, the modern ones have a lifespan measured in months. Everyone knows I buy and refurbish trucks, mostly deuces and I keep them anywhere from 6-24 months before I sell them. I’ve had several trucks where I bought a new flasher relay when the truck came home, then before I sold the truck, had to put a new one on because the replacement died.


Certainly there will be somebody who will say “Well Clinto, I’ve never had this problem, so obviously you’re doing something wrong”.


Let me tell you-every one of these I have installed has had the mounting surface cleaned with a wire wheel and new, correct, mil-spec, hardened star washers used to ensure a good ground. The pins in the cannon connector are cleaned and dielectric grease used. The bolts/screws/nuts/washers cleaned with a wire wheel as well. So it’s nothing I’m doing.


Maybe it’s load related! Hogwash-several of these trucks have never had their 4 way flashers engaged and several of them never had a trailer hooked to them. You’re going to tell me the load of 2 turn signal bulbs is enough to kill one?


So at the end of the day, I think it’s safe to say they suck. Like everything else in this Country, corporate America has figured out how to make things cost 10 times as much as they used to while simultaneously lasting 10 times shorter than they used to. I’ve owned lots of Sixties cars that had their original flashers still in them. Good luck buying any flasher relay today that will last 30 or 40 years.


Now, if they were $5 or $10, it wouldn’t be the end of the day. But about the cheapest I can buy them regularly is $45 shipped and you have to wait a week for it to show up.


Why am I babbling about all this?


I sold a deuce the other day I’ve had for about 2 years. And when I bought it, it needed a relay, so I put a new one in it. And literally, the morning the guy is coming to look at it-I get in it and it has no turn signals. So I stole the one off my personal truck, HQ43, an ’87 M35A2C and put it on the truck for sale. This left my personal truck with no flasher and I really didn’t want to put a crappy repro on it that would die in a few months.


So I started trying to find an alternative. As with all of my modifications, there were several parameters that had to be met before I could continue:


The modification had to improve the vehicle significantly enough that it was worth doing. I like my stuff factory correct, whether it’s a Road Runner or a Deuce, so in order to modify it, it has to fix a really glaring problem or create an enormous payoff.


The modification has to be completely undoable-anyone who has owned a Sixties musclecar knows what I am talking about-having to plug weld a hundred holes in the firewall that Johnny Redneck drilled for aftermarket gauges, choke cables, beer drains, smoke exits, whatever. So I try to never modify a factory wiring harness and I try to never drill holes or weld on a vehicle. So the stock cannon connector had to stay and preferably no holes be drilled in the inner fender.

The modification has to be reasonably priced-if the factory relays are $50 and the new one is $500, you might as well keep buying the factory one.

With all that in mind, I went off to see what others had done. I found other people on the forum who had already come up with a good solution, so I basically stole their idea and refined it.

http://www.steelsoldiers.com/showthread.php?132184-Economical-turn-signal-flasher-repair-option was a great help and on the M35A2 Facebook page, some users shared their pictures of their solutions.


Once I had these, I had to decide if I wanted to carefully remove the sealer from the factory relay and install a civvy flasher in there and then I needed to decide if I did it this way if I wanted to “re-seal” the new one or leave it in there. Alternatively, I could purchase or fabricate a new “casing” for the civvy relay and remove the cannon connector from the factory case and install it on the new housing.


Once I spent all afternoon trying to remove the nuclear sarcophagus grade sealer from the factory case, the amount of Heineken I had to drink to calm me down enough to not want to hunt down everyone ever involved in the factory relay design and kill them all brought work to a screeching and stumbling halt. The next day, I decided a new case was in order because leaving the factory case on my truck might be a psychological trigger and I don’t want to deal with that.


So off to Home Despot to see what they’ve got. I take the old relay housing to match up dimensions. I had an idea of using a gangbox because it was plastic (wouldn’t rust), it would be water tight and it would be cheap. And I find that this standard gangbox mounting hole dimensions line up with the factory relay!

20150109_165929.jpg


So I am thinking I am a clever dude. More on this later.


So, got my gangbox and cover, went to Napa and ordered an EG23 relay, got a generic 3 pole headlight connector (NAPA 787100) and started. In testing the EG23 3-pole relay, I released the smoke monster. Not sure if I had it hooked up wrong or if it was defective.


So I ordered the EG22, which is a 2 pole relay. It is nice that it doesn’t have a ground, so the issues of potentially bad grounding are out of play. EG22 simply has power in and flashing power out. I read somewhere it isn't polarity sensitive as well. Haven't tested that myself.

So, the actual job:


Parts list:
Gangbox
NAPA 787100 headlight connector
Tridon EG22 or EG23 relay
Screws to attach cannon connector to gangbox
Solder, heat shrink tubing
Heineken, Guinness or similar moderate quality beer



Procedure:
Ultimately, the cannon connector from the relay needs to be installed in the gangbox. If you can’t find one to buy somewhere, you’ll need to remove yours. You have to get the connector with it’s 3 pins out of the relay housing. I tried both the cheesy “Mapp gas” type torch and my Oxygen/Acetylene torch and neither melted the sealer, so it’s a drill, a flat blade screwdriver and patience. Once you’ve got the connector out, it will look like this:

20141231_095130.jpg20141231_095136.jpg


Luckily, the one thing the manufacturer did right was soldering the wires to the 3 pins, so heat them up and remove the existing wires.

20141230_173600.jpg20150104_175353.jpg

The 3 pins in the connector are A, B and C. C is circuit 90, the ground. If you’re using the EG22 relay, you can leave this one open. B is the flasher input (solid power) and A is the flasher output (flashing power). So you’ll need to connect the B pin to the X terminal on the EG22 and the A pin to the L terminal on the EG22. The circuit letters are molded into the rubber and can be very hard to read, so I have applied my phenomenal photoshop skills in an effort to help you identify which circuit is which.

harness connector labeled.jpgrelay connector.jpg



I soldered the wire ends of the NAPA headlight connector onto the pins, then added shrink wrap. The pins pull out of the back of the cannon connector, so you can do this easily on a workbench.

20150104_185623.jpg20150104_183850.jpg20150104_185628.jpg


You also need to mount the cannon connector to the gangbox. I cut the connector off the end of the gangbox, opened it up just a hair with a deburring tool on a drill and attached the connector here.

20150104_191502.jpg20150104_191352.jpg20150104_191308.jpg20150104_191301.jpg20150104_192944.jpg

Here's where I screwed up. I hadn’t anticipated the connector mounting on the end wouldn't fit behind the rear fender brace. After I had built the first box, I tried every way to mount it but it just wouldn't clear. I decided to build an adapter, a mounting plate that would mount in the stock holes on the inner fender that would allow the box to move over enough to make room for the connector. I finally gave up on an adapter plate and bought another gangbox.

The last of the how-to is in post #2 to make room for pictures.
 

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clinto

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Here are the Home Despot part #s so you can grab exactly what you need:

UPC codes.jpg

And another schematic of the EG22 relay, in case my photoshopped version wasn't clear:

download.jpg

The final version can be seen here:

20150118_140218.jpg20150118_140809.jpg20150118_140207.jpg20150118_140202.jpg20150118_140213.jpg

And can be seen installed on HQ43. You can see the pattern of the old unit in the paint on the inner fender:

20150118_142349.jpg20150118_142409.jpg20150118_142333.jpg20150118_142340.jpg





Once it’s done, you have a truck that can be returned to stock without any work, can use a $15-20 flasher versus a $40 one and you can typically have it in a day, versus a week.

Another benefit to using the gangbox is that there is enough space to put a spare relay in there. So if you're 500 miles from home and it dies, you can pull the cover, swap the relays and order a new one when you get home.

One thing that is still unknown (other than how reliable this will be)- will condensation be an issue? I considered putting a 90° elbow, facing down on the end of the box instead of capping it, but then if you ever forded water that was deep enough, you'd fill up the box with water. But, with the drain, if condensation accumulated, at least it could dry out. So I'll inspect this in a month or so and see if there's moisture collecting in it. I'll address it then.

Today I tested it with a trailer connected and the 4 way flasher engaged and I left it flashing for 30 minutes. So that's a full load of 6 bulbs flashing for half an hour and there was no failure or heat generation (overloading) in the flasher.


Much thanks to Doghead and all the other SS members who provided much research and knowledge in this thread: http://www.steelsoldiers.com/showthread.php?132184-Economical-turn-signal-flasher-repair-option

I hope this helps some of you save a buck and not have to constantly replace crappy relays.

DISCLAIMER: I have not tested this with LED lights, so I do not know if you will have issues. Napa's technical data can be seen here:

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Flasher-Turn-Signal/_/R-NF_EG22_0006534051



 
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clinto

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So you just used a standard 12v flasher relay? And then if you use one of the electronic 2 pin flasher relays it should work LED lights without issue as well.
EG22 is a 24V flasher relay.

I do not know if this will work with LEDs-thank you for bringing this up. I will edit the original post and add that disclaimer.
 

Amer-team

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Since you destructive tested the old unit, you could probably paint your new box semi-gloss black and cut out the old nomenclature tag and afix it to the new case. Nice work and thank you for the write up.
 

RustyJunk

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Good mod Bro! Will this work on my GEO Metro? Right now, when I turn on the blinkers, smoke comes out of the dash and I get a phone call from a destitute boy in China.
Thanks!
 

Tow4

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I used fire wrench technology to burn out the potting in the flasher can I modified. Either it wasn't epoxy like I expected, or it may have had a lot of sand mixed in. It was time consuming to remove but it all came out in the end.
 

clinto

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Ordered my flasher today. Should be here Wednesday. Clint, do you still need me to send you that bad flasher relay?
I'd love to have it so I can build one for my other truck, HQ41.
 

clinto

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Took my first "trip" in the truck with the "clinto relay conversion" (rofl). Approximately 100 miles when we went to the BBQ Saturday with Andy3 and the guys. Pulling Dave's equipment trailer with my 24-12 GI adapter and going through a lot of traffic and a lot of turns, no problems whatsoever.

Wonder how long it will be until trucks start showing up on Craigslist with the "clinto flasher relay" conversion. :D
 

Jeepsinker

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I got all the parts to do mine. I'll be testing use with all LED lights to verify whether it works or not. I'll get you an old one in the mail in the next couple days so you can convert your other truck. I have to mail some money orders and parts out so I'll send it to you then.
 

cranetruck

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There are some compromises in the design of the newer flasher modules as was explained in the 2004 MVM article on the subject. For example, the original solid state flasher unit was designed to handle an overload until the CB in the 3-lever switch tripped, while the new (at least some of them) have no overload protection at all and blow like a fuse.

mvm feb 2004.jpg

There is one problem with allowing the CB to trip and that is the loss of all lights, including headlights. It happened to me one time and it prompted this solution, which isolates the flasher with a relay and also the the headlights from the 3-lever switch CB with a second relay.
2007 1102 racor fuel heater, flasher headlight relays.jpg
 

clinto

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I've now had this upgrade on my truck for almost 6 months and it's awesome. The new Napa relay is so heavy duty that I can use my unit to test other trucks. I had one customer's truck that had a bad turn signal switch that smoked a new repro relay but mine survived with no issues (in this case it was too good-mine surviving the bad switch sort of sent me in the wrong direction diagnosis wise, rofl).

Once or twice I've turned on the blinkers and it took a second longer for the blinkers to start blinking-I don't understand what causes that-perhaps the flasher gets "stuck" in the open position? But otherwise it is flawless. And I've checked the inside of the box I built and it's been dry the two times I've checked.
 

clinto

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Once or twice I've turned on the blinkers and it took a second longer for the blinkers to start blinking-I don't understand what causes that-perhaps the flasher gets "stuck" in the open position? But otherwise it is flawless. And I've checked the inside of the box I built and it's been dry the two times I've checked.

I was wrong. It wasn't the blinkers not blinking, it was the indicator light on the turn signal switch not illuminating when the blinkers were on. Poor grounding of the switch to the column.

So I've had zero issues since installation and I'd say half the time the truck is driven it's with a trailer.
 

The Stig

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Thanks to all the info in this thread I was able to make this same conversion to resolve an intermittent issue with mine. Most difficult part was removing the connector but after that was out it was a piece of cake. I ended up getting an all aluminum project box that has the same mounting dimentions as the original box so I could reuse the factory holes. I hoped that once complete, and painted it would look correct or like it belonged there that nobody would notice it. I'm happy how it came out. Even more thrilled how fantastic it works. Now its just a simple as removing the top of the box and just replacing the relay.

Thank you! Here are some pictures of my box.

anyone interested it is a Vetco Electronics Part Number: CES-64BS15MF

IMG_1872 (2).jpgIMG_1874 (2).jpg[h=2][/h]
 

Csm Davis

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Thanks to all the info in this thread I was able to make this same conversion to resolve an intermittent issue with mine. Most difficult part was removing the connector but after that was out it was a piece of cake. I ended up getting an all aluminum project box that has the same mounting dimentions as the original box so I could reuse the factory holes. I hoped that once complete, and painted it would look correct or like it belonged there that nobody would notice it. I'm happy how it came out. Even more thrilled how fantastic it works. Now its just a simple as removing the top of the box and just replacing the relay.

Thank you! Here are some pictures of my box.

anyone interested it is a Vetco Electronics Part Number: CES-64BS15MF

View attachment 599870View attachment 599871[h=2][/h]
That looks great
 

catskillpond

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We converted to the eg22 on three trucks they will operate up to 18 bulbs with no problem. I carry an.extra flasher on each vehicle have not changed any since install. Amazon had them half the price as napa.
 
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