Starter Solenoid

[Ando427]

So I know that there is a wiring diagram in Appendix F of the -20 TM, I already looked at that. I got stuck on the trail the other day after shutting off the truck and figured out that the small red wire going to the starter solenoid wasn't powering the solenoid. We jerry rigged a wire from that terminal to the batteries and it started the motor right up. Now that I'm actually trying to fix this I can't for the life of me figure out what the archaic box on the wiring diagram actually is physically under the hood to figure out where the small wire goes in the engine bay. I assume it's something with a fusible link and that that is what blew causing the loss in power delivery. With that being said, does the wire run up to the diamond shaped bus that's on the firewall next to the glow plug relay?

 

[doghead]

It goes to the relay that is under the dash.

They are a known problem(most notably for sticking on).


Look at the stickies for the doghead relay modification. It will show you where this relay is. Modify if you want to or simply replace the relay if this is where your problem is.

Basically, the system uses the "stock" (like every normal GM)12 volt wiring and actuates a relay that is fed with 24 volts, to actuate the starter solenoid.

 

[Ando427]

Hmmm, I actually did the doghead relay mod already and had been running it for quite some time with no problems. The trails today were pretty rough, I wonder if all the bouncing around did something to the relay? Even after I installed the doghead relay I never heard a noticeable click from it that others were reporting. I guess it would have to be the red wire off the relay that goes down to the starter solenoid just above the starter motor then?

 

[doghead]

Actually, the wire from the relay to the solenoid is purple.

The red wire comes from the buss bar. Probably has a fusible link in it. It should be seen in the schematic.

 

[MarcusOReallyus]

The trails today were pretty rough, I wonder if all the bouncing around did something to the relay?

Theoretically possible, I suppose, but I've never heard of it happening. I'd spend your efforts looking elsewhere. Instead of firing the parts cannon at the relay, test it. Make sure it is getting the correct voltages at the correct places.

 

[Ando427]

Thanks for your help guys. I pulled down the doghead relay to test it and that's when I realized that the purple and white wire wasn't connected. Apparently I had done a less than good job of crimping that wire into its ring terminal when I did the mod and it must have popped out on the trail yesterday

 

[MarcusOReallyus]

Did you use one of these crimpers?



Utter crap. I would not pay 99 cents for one of those. Your experience is why.

 

[ralbelt]

Marcus I use a pair similar to those and follow up with a pair of vice grips, so far no problems unless I crimp too hard and fracture the wire. What do you use?

 

[pjwest03]

I use one of these buggers myself. Ratchet style crimpers do a much better job.

 

[Ando427]

I actually misplaced my crimper a while ago and have been using pliers hoping that the crimper would turn back up, but it looks like I need to bite the bullet and buy another set. I haven't had problems using my crimpers in the past, but apparently my crimping skills with pliers aren't very good; I'm liking that set that pjwest03 is showing there.

 

[MarcusOReallyus]

I use one of these buggers myself. Ratchet style crimpers do a much better job.

View attachment 658843

Finest kind. Those will give you good results, consistently.


Pliers? Vice grips?

That's why crimps have a bad name. Wrong tools.

They are very reliable when you use the correct tools.