I just recently bought a 1985 6.9 idi diesel f250 an I need help understanding the wiring harness an gp harness the previous owner put in a push button an Minecraft beru ZD1A.gps an started good 1st time then gps were shot theres a lot of wires that are either short or liw voltage including orange wires for gp harness. An now my little ground wires are shorting out aling with alternator wire that hooks to starter relay if anyone can help me please let me know!!!!!!

 

Yeah sorry about that, I was in a hurry. So my problem

 

Yeah sorry about that, I was in a hurry. So my problem is gp burnouts. I'm aware of the relay, controller problems, an much more ive read off this site. The controller is bypassed (I think) it has a temp push button installed with one wire spliced with purple wire an other going to large terminal with the battery cable. I have been going through the wiring and most important wires ( that I know of) are getting voltage. When testing plugs I have no resistance. An im afraid of putting New ones in cause I only have funds for one set an won't have funds anytime soon. The previous owner says that when he put in new plugs it started up the first time great an plugs were bad afterwords (he used motorcraft beru). Due to him not solving the problem, an to avoid to much air intrusion (from what he says) he used ether every time to start it up once or twice a week. He said he only held button 8 sec or so. But my conclusion is either he held it to long, the controller isn't bypassed correctly, or something is staying on that burns them out. The cables were pretty bad with corrosion but I only replaced the connectors not the whole cable ( thats highly recommended). Ive been working on it for a while now an need it fixed but am limited on funds any advice helps, thanks

 

First thing I'd do is check the relay to make sure it's working right. I'd have a friend hold the button while you check the relay with a volt meter. Check from the battery feed (on the relay) directly to ground, and check from the switched terminal (the one that feeds the glow plugs) to ground. The voltage should be the same when the button is held down and there should be NO voltage to the plugs when the button is released. If there's a voltage drop through the relay that will cause a problem. If there's still voltage to the plugs with the button released it'll burn out the plugs.

How big is the wire going to the relay? Have you checked the wires running to the switch in the cab to make sure they aren't shorting out?
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How cold is it where you are? 8 second​s might not be enough anyway.

 

ive tested relay by jumping 12v to the small term where the purple wire went to an it tested good. Im not getting power to my small wire that hooks to the starter relay so im trying to find the short in that now. Another thing is , I dont think the controller is properly bypassed cause the wire to the switch is spliced to the purple wire leaving the purple wire still hooked up to the plastic housing. As far as connection to both relays they tested good with my meter. But one thing that I cant figure out is the owner before the guy I bought it from added s continuous duty solenoid hooked up to starter relay an to the main power wire tyats yellow to the cab not to sure if anyone might k ow why other than I think to reduce power flow? An wire that connects starter relay to gp relay us 10 gauge

 

This is the relay you have correct? Mine is newer so it's different and I want to make sure I'm looking at the right thing.

Wow those wires are tiny, my 91 had two 10 gauge wires to and from the relay. But I'm going to assume you have factory wiring.

I would make sure your switch gets power directly from either the starter solenoid or the battery, and it goes directly from the switch to the purple wire. If anything is still connected to the old controller just unhook it at this point. A good working manual setup is better than guessing what's been done at this point. If your switch is spliced into the controller wire like I think you're saying, cut it and hook only the switch up.

As far as the solenoid, are you able to post a picture? I actually was thinking about doing this just because there isn't much room on the starter solenoid but if it's wired weird maybe that could be part of the problem.

 

I cant get good pic cause its bright out but only wires I have hooked to starter relay is a wire that connects starter relay to gp relay, one wire connected to continuous duty solenoid,one that hooks to voltage regulator with fuse link, an another that has a 20 gauge fuse link that connects to a little yellow wire that feeds into cab on one side then a little one in middle of starter relay an one ground wire on the other side of relay. As far as I know most important wires are hooked up, not to sure if that plug that hooks to ip with one green wire the other black, is important or not?

 

The one that hooks to the injection pump with the two flat spade connections? That's VERY important. One of those is the fuel shutoff switch. Without power to that you won't get any fuel through the injection pump!

 

when I pulled the plugs they were black an carboned up any thoughts?

 

I think that might be normal. My old autolite plugs were like that when I pulled them. I think they were working but I had blown an under spec fuse and found out after putting the Motocraft ones in. Mine had only been in for about 2 months anyway.

 

so im almost done with the gp system I think. But to be safe I have a couple questions. I completely unhooked the controller an was wondering if the ground wire on the back of the engine that hooks up to the controller part of the harness still needs to be hooked up? An as for the gp harness, it should only receive power when the key is on right? Yesterday I was testing the harness an it had power when the key was off, but with key on, it had no power, I read that is most likely cause I had a starter solenoid in place of the gp solenoid, which makes sense. But wouldn't it receive power with key on as well? Is it ok to wire the push button switch directly to gp solenoid? I have 1 wire to the positive post, the other to small post in place of purple wire. An ive already been told it will air lock , but just for the record, I lost one of my gps so I was wondering if its ok to start it without one gp in place, I have new ones coming but not trying to burn them out as im on a budget. Also my battery cables were pretty nasty but I was wondering if I should still replace them cause I only replaced the terminals. An I know its a little off topic but I got a Mitsubishi gear reduction starter the truck came with, as much as I hate foreign ****, I read it excels torque verses stock.

 

First: Please, please use line breaks and formatting.
Your post is almost impossible to read.
This isn't text messaging.

With a push button setup, fewer glow plugs will heat up faster, so you need to hold the button for a shorter amount of time.
If your glow plug is not in the engine at all, you are asking for trouble. It'd probably run, but have a very high pressure spray of air and stuff coming out of that GP hole, and you might suck crud in when the piston goes down.
I wouldn't try it.

Well... Yes and no.
All trucks after the 83? model year went to a gear reduction starter. Mitsubishi and Nippondenso both make starters that are compatible(and there are a lot of clones/rebuilt units based on one style or the other.

Both work equally good in my opinion - they *both* have gear reductions in them.
Unless your particular starter is a high-torque unit, they both draw the same approximate amount of power and will crank approximately the same speed.

What happens(to both units, mind) is that over time crud from the brushes ends up on the commutator ring. The grease inside hardens up, and now the starter won't have nearly as much power.

Also, these starters have 4 brushes(two pairs). At the end of it's life, with the brushes worn down, you will find that one of the brushes will end up being slightly shorter and stop making contact. When that happens, the starter is effectively running on only one pair of brushes, and will crank much more slowly - it will sound like a dead battery.

If you are on a budget, you can rebuild a starter pretty easily - it's just a matter of disassembling it, cleaning it, replacing grease and(if needed) replacing the brushes with new ones off Ebay.

 

ok I got everything hooked back up. I don't here the relay click a bunch but when I press the button it clicks once an my harness then supplies power as long as I hold the button does that sound accurate?

 

...That's a push-button setup, yes.
And you are the controller. Holding the button too long *will* overheat the glow plugs.

 

Do I have to use a torque wrench for tightening or can I just use a regular wrench?