Burnt Fusible Link, Doghead Relay Stuck

[Bdenton]

Six months ago I installed a starter from DB Electrical and did the doghead relay mod at the same time. It has worked flawlessly up until yesterday.

I hit the key and got a single 'click' as if the solenoid on the starter was stuck. Tap on the solenoid a few times, hit the key, same thing but this time I smelled smoke.

The fusible link numbered 16 had burnt in half and some kind of burnt liquid was oozing out of the solinoid on the starter.

Replaced the starter with a spare, replaced the fusible link with an inline fuse, hooked the batteries back up and the starter started to run away. Turns out the doghead relay had welded the contacts together too!

My question is what in the world may have caused all this to happen? Relay on the starter took a crap and back fed current to the relay under the dash and burnt everything along the way? Anyone else ever had this problem?

 

[TexAndy]

https://www.steelsoldiers.com/showt...fter-Starter-Run-on-Explained-and-Illustrated

 

[cucvrus]

Six months ago I installed a starter from DB Electrical and did the doghead relay mod at the same time. It has worked flawlessly up until yesterday.

I hit the key and got a single 'click' as if the solenoid on the starter was stuck. Tap on the solenoid a few times, hit the key, same thing but this time I smelled smoke.

The fusible link numbered 16 had burnt in half and some kind of burnt liquid was oozing out of the solinoid on the starter.

Replaced the starter with a spare, replaced the fusible link with an inline fuse, hooked the batteries back up and the starter started to run away. Turns out the doghead relay had welded the contacts together too!

My question is what in the world may have caused all this to happen? Relay on the starter took a crap and back fed current to the relay under the dash and burnt everything along the way? Anyone else ever had this problem?

Say it ain't so. This can happen to any type of relay/solenoid. There is no 100% fool proof way to wire it. It happens on all makes and models. As long as 2 metal contacts make contact and form a connection you will have arc and weld. I see it in house wiring, trucks, boats, anything with a electrical connection. I had several Ford's burn up starters and cables when an unknowing what to do driver had the vehicle. They just sit or stand there and watch it burn up. I would just use the special tool and end it instantly. Up top is the game over tool. Legal in all 50 states and the District of Columbia. Sorry to say. I am not an electrical guru by a long shot but cut the 24 volt cable and stop the current. Game over. I wonder if the big switch above would work if it was tripped to the starter cable. Why Not?

 

[doghead]

What relay did you buy/install?

Have you removed it and tested it with an ohm meter to verify the relay is stuck closed?

I do not recommend hacking your battery cables to install a disconnect switch. This has been discussed many times before. If you don't understand the electrical system, let someone who does, help you.

 

[Evil Dr. Porkchop]

6 months sounds about right for a DB Electrical starter, mine lasted less than a year. It also burned up some wiring and ruined the (stock at the time) starter relay.

 

[Bdenton]

Thanks Dr. Porkchop, that's the input I was looking for.

I've read the link posted numerous times before I did the doghead mod. Of course there is no 100% guaranteed way to cure the wiring nightmare these trucks have. Yes I tested the relay, traced wires and made necessary repairs.