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markrinker
07-30-2004, 04:28
Recently had e-brake wiring repaired on trailer. They replaced plug and a few connections. Cab brake controller checked out good, everything works fine, until...

Pulled off on a narrow shoulder to check straps, put on flashers. When I got back in the truck to take off, forgot flashers until I felt a trailer brake 'surge' in time with the flasher!

Sure enough, the trailer brakes are being activated by the flashers. Annoying if everything is low speed and the brakes are set lightly. Dangerous at highway speed if the brakes were set heavy.

Where to look? Short in the plug?

moondoggie
07-30-2004, 08:00
Good Day!

In my EXTREMELY limit experience, this is normal. My pickup & the Sub both have the Tekonsha controller that was their best non-accelerometer model at the time I purchased them. I vaguely remember them referring to this in the literature.

There may be a fix. I'd certainly ask the brake controller mfg.

This only happens when the four ways are on - do you drive with them on often? It's never presented a problem in my experience.

Blessings!

Brian Johnson, #5044

HowieE
07-30-2004, 11:57
It looks like who ever wired the controller picked up the brake signal at the wrong place. If you look at a wiring diagram for the hazard lights they open the brake light input signal from the brake pedal when the hazards are turned on. In this position if they had picked up the controller input signal from a brake light line the brakes would pulse when the flashes were on but would seam to work normaly when the flashes were not on.
To correct this makes sure the red wire on the contoller, brake signal input, is connected to circuit #227 which is a white wire coming off the brake switch.
Now having said that it is near impossible to get to the brake switch and this wire at that location. You can also find circuit #227 in the lower left kick panel were it is branched out to supply the center light at the back of the truck.
Open the lick panel and look for a white wire in the corner of one of the connectors that has voltage on it when the brakes are applied. This wire will be in the corner opposit the release tab. There is also a white wire just next to this one on the other side of the connector so make sure you test with the brakes applied and get the right one.

DonG
07-30-2004, 15:57
Mark,

Your experience is exactly the same I experienced with the Prodigy on my 2003 truck. I used the cable provided with the correct wiring for the 2003 model year.
All was well until I tried to use the four way flashers while trying to slowly climb a steep hill. Everytime the flashers cycled, the trailer brakes activated.

This was another one of the reasons I got rid of the Prodigy.

Don

ropinfool
07-30-2004, 17:10
Well I have installed many brake controllers and this is pretty normal for a chevy. Even when tying into the white wire off the brake switch. There is a blocking diode, I want to say drawtite #5100 (could be wrong, it's been a while), piece of cake to install, works like a charm. You never know when you are going to want to drive with your flashers on, get it fixed!! John

markrinker
07-31-2004, 10:43
Thanks for the advice, I'll get it taken care of before snow season.

Last thing I want is to have an employee jack-knifed with the skidsteer in tow, because he was trying to be 'safe' during a snowstorm and run the flashers.

Its amazing, but never noticed this before.

Cooperrw
08-01-2004, 04:11
I'm glad you brought up this subject Mark, I was towing my horse trailer up a steep grade on I-40 recently and decided to use the 4-ways because my speed had dropped to 40 mph. I couldn't feel the brakes activating but the controler was flashing in synce with the flasher's. This forum is a wealth of knowledge and boy do we need it with these Chevy's! :D

markrinker
08-01-2004, 04:49
Hey River Rat. Kingman, AZ sure is beautiful country. A good college friend of mine is detective there. His name is Paul Holstine.