truck's flasher module keeps burning out; trailer's fault?

I have a 2003 2500hd with the tow package. If you have the tow package the control relay activates tow separate circuits. One for the truck, and one for the Trailer.

The circuit is fused at 10 amps per side (left, right). That fuse block is on the drivers side with the door open (there are three fuse connection points on the Chevy's - one under the hood, one under the dashboard and one on the side of the dash on the drivers side).

Coincidentally I'm having an issue with my turn signal relay - but someone posted the answer for me under the tow vehicles section. his was a 2005, had the same problem and it was resolved.

If you actually have more than 10 amps on either the left or right turn signals, that could cause the problem, but it's fused at 10 amps, so I don't think you're exceeding 10 amps or the fuse would have blown.

My flasher is hard to access. A real bear.

When I went through the third "Premier Brands" electronic flasher in three years I had enough. End of the line...

I purchased a Sure-Power flasher. I know who designed it and I know the limitations of even those so-called "heavy duty" electronic flashers. The Sure Power is guaranteed blow-up proof, and it has impressive circuitry to protect against high voltages, overloads, transient voltage spikes, reverse polarity, miswiring, and it laughs at direct short circuits. Connect the output to a a dead short negative and return a year later and reconnect it to a working circuit.

I do not have time to deal with at at-fault accident caused by garbage grade electronics. The Grote, and other so-called heavy duty electronic flashers are not in the same universe as the Sure Power.

When my AUTOMOBILE dies, I'll have my grandkids pull the flasher and then they can pass it along to their grand children.

enblethen wrote:
I would suggest trying an electronic flasher in your '03. Many of the standard flashers are of the bi-metal type with contacts that switch the load.
Electronic Flasher

Where as I suggest the exact opposite, a good HD Bi-metal flasher should handle the load no tribble less there is a dead short on the line somewhere.

Bi-metal flashers, as I said above come in two types, Specific load and HD.

Specific load when you turn it on current flows, heats the bar and opens the contacts... The greater the load (More lamps) the faster it opens.

HD works the other way around,, A heater wire is wound around the bi-metal strip when you turn it on only a tiny amount of current flows, not enough to light a single 1141 Turn element,... Once this wire heats the metal enough it snaps closed, and major current flows, one lamp or a dozen, it takes about the same amount of time, and the contacts can take a dozen.

Now that the heater wire is shorted the thing cools, snaps open and the cycle repeats.

Solid State flashers are fairly new, these Bi-Metal flashers have been around for a long time.. They are standard on most vehicles to this day and usually last the life of the vehicle, though you can get replacements I think in nearly 50 years of driving I have replaced ONE, one time.

enblethen wrote:
I would suggest trying an electronic flasher in your '03. Many of the standard flashers are of the bi-metal type with contacts that switch the load.
Electronic Flasher

Where as I suggest the exact opposite, a good HD Bi-metal flasher should handle the load no tribble less there is a dead short on the line somewhere.

Bi-metal flashers, as I said above come in two types, Specific load and HD.

Specific load when you turn it on current flows, heats the bar and opens the contacts... The greater the load (More lamps) the faster it opens.

HD works the other way around,, A heater wire is wound around the bi-metal strip when you turn it on only a tiny amount of current flows, not enough to light a single 1141 Turn element,... Once this wire heats the metal enough it snaps closed, and major current flows, one lamp or a dozen, it takes about the same amount of time, and the contacts can take a dozen.

Now that the heater wire is shorted the thing cools, snaps open and the cycle repeats.

enblethen wrote:
You may want to build a relay setup. Run large power wire to main contact, contact output to trailer lights. Use the output from the module to operate the individual functions. Would take two relays, one for each turn signal/brake light function.

I'll probably try replacing the trailer bulbs with leds first; I think that may solve the problem. If I still have problems I'll consider more complex fixes.

You may want to build a relay setup. Run large power wire to main contact, contact output to trailer lights. Use the output from the module to operate the individual functions. Would take two relays, one for each turn signal/brake light function.

Enblethen, that's exactly what I have now, except that is the more expensive one for led's. Theyre electronic and all have a rated life, just like a light bulb. The OP seems to be eating modules at a ridiculous rate. And I believe towing is directly related to life span. When the first one went, I had no right turn orbrake lights on the trailer, although the truck was fine. After chasing bulbs and wiring I replaced the module and done. The last one, hitched up to leave camp, put my 4 ways on to do a walk around, nothing, no signals, no 4ways, no brake lights, running lights were the only thing that worked, not a very comfortable ride home.I carry a spare now.

I would suggest trying an electronic flasher in your '03. Many of the standard flashers are of the bi-metal type with contacts that switch the load.
Electronic Flasher

Ihave a 2003 gmc sierra and am now on my 3rd flasher module. I have 170k on my truck now and probably replaced the last one about 10k ago, so I gues I get about 80k out of a module. My truck is usually hauling, its not my daily driver, and my trailers have 4 tail lights, plus the truck, and led turns in the mirror. The module is located under the dash and is a 10 pin rectangular box. As far as I know, the only option u have is to buy the $80 module if u have led's. They are rated to last 1000 hours, like a light bulb. It also controls your DRL's and brake lights. If you look up the part on the napa site u will see they offer 1 for $30, which is what I use, and 1 for led's. A lot of auto parts stores only carry the led module and burn ya for the 80 bucks. Unless you,re driving like crazy, I would think you have a problem somewhere.

Ihave a 2003 gmc sierra and am now on my 3rd flasher module. I have 170k on my truck now and probably replaced the last one about 10k ago, so I gues I get about 80k out of a module. My truck is usually hauling, its not my daily driver, and my trailers have 4 tail lights, plus the truck, and led turns in the mirror. The module is located under the dash and is a 10 pin rectangular box. As far as I know, the only option u have is to buy the $80 module if u have led's. They are rated to last 1000 hours, like a light bulb. It also controls your DRL's and brake lights. If you look up the part on the napa site u will see they offer 1 for $30, which is what I use, and 1 for led's. A lot of auto parts stores only carry the led module and burn ya for the 80 bucks. Unless you,re driving like crazy, I would think you have a problem somewhere.