robbynne

Just as an aside, I disassembled my failed trailer tow left turn relay to diagnose its problem. Photo thirteen shows the relay. The metal leaf spring to which the contactor is attached broke due to (apparent) metal fatigue. Nice work Dodge and Tyco....

http://byfiles.storage.live.com/y1ph...ZfYtn-iD_8LjZQ

sabersix

Great write-up!

davidj54

It doesn't look burnt so I'd say they designed it with too much force on the part when engaged so during repeated use (think blinking) it fatigues the metal. The actual design may be fine they may have gotten some near off spec parts. The end outcome is the same though. Not good for us consumers.

robbynne

Yes, there were no signs of burning. Given the number of owners reporting this problem, I'd say the part was marginally spec'd.

The entire design of the trailer tow wiring package is lame. Regardless of whether a trailer is hooked to the system, these relays operate (needlessly) whenever the turn signals of the truck are used. It seems to me that they could have designed in a sensor or switch in the trailer tow wiring and used the PCI bus to communikcate to the Front Control Module to activate the trailer tow relays ONLY when there was a load (trailer) attached.

SOhappy

...or they should've just made the ALL the relays external so they'd be easy to replace. What are all those empty slots in the PCM for anyway???

nsxt

Many relays are spec'd to 100,000 cycles. Higher reliability are 1M cycles. If your turn signal blinks 100 times per day, then you have 1000 days worth of blinking on a standard relay. Not very many by any means.

On a different vehicle I had to replace the trailer relay box. I decided that P-channel mosfets were vastly superior, although at $6 each they were kinda pricey relative to a $2 relay. Never had any issues again.

nice writeup on the IPM fix, robbynne

And sohappy is correct, all of them should be plug-in replaceable. But then you have contact corrosion issues.....

robbynne

The Tyco relay which failed is spec'd at:

10,000,000 operations WITHOUT load

greater than 100,000 operations at 25A, 14V

for whatever that is worth...

MikeyT

Rob where is the part 1 write up? The link takes me to a single picture.

AlK

Here you go.
https://www.dieseltruckresource.com/...d.php?t=222371