Weird electrical/starting issue '84 Ranger Diesel

[rangerrattler]

Hey guys, it has been forever since I've been back on the board. The rangerrattler has been running well except for an issue with water consumption still, but I have a new soon-to be-refurbished head that I'm going to get installed soon as it appears I have a crack in it somewhere..

Anyway, after a long drought from the Diesel this last couple of years, I've got another small issue and wonder if I can get some help here-

I have newer fresh batteries with plenty of charge, but on occasion of late the starting process begins with everything seeming normal until I turn on the glow plugs..a loud "clunk" happens on occasion, followed by what seems to be a totally dead "system". No glow plug wait lite (although in the dark It glows very very lightly) followed by no crank ability at all.

I had a mechanic friend come out to help me the other night and we thought something simple had fixed it. I noticed a ground wire from my driver's side battery was grounded to the body, rather than the engine block. A test light lit up when running it from the positive terminal to the body, anywhere, which is not right..Correct?

So when we moved the ground wire to the engine block, we were back in business! A great crank and startup. BUT the other day I tried to use the truck and she did exactly the same thing as before..clunk on the first start of the ignition turn, with no glow plug lite. The weird thing was, when going back to try it again about a half hour later, everything worked perfectly!

Now I'm stuck and won't want to leave my house with this thing this unreliable. What the heck is happening? Is this perhaps the glow plug circuit solenoid or whatever that is called? Any thoughts?

Thanks for any thought on parts or help. All the best! Brian

[83rangerguy]

I know this doesn't correct what's wrong but it is a fix if you can't get to the root of the problem....a lot of guys just end up bypassing the glowplug system and wiring up a manual switch, I suggest a momentary switch so it can't be left on accidently and burn up your plugs.

[wayne83]

I know you have said you have newer fresh batteries in the truck, but have you actually checked the cold cranking amps not just the volts? you can have 12 or more volts but only have 100 cca when you should have above 500 for each battery. my truck was doing pretty much the same thing for almost a week until I finally load tested them. when I load tested the batteries they were both junk, but I had plenty of volts. just an idea

[gradyc]

Bad connections at the battery can also cause it.

[fatguppy]

You don't say if you charged the batteries or boosted/jumped it after one of these events? Also check the relay that is located on the drivers side fender well. Its tucked over by the air-cleaner and hides from view. This relay provides power to the entire trucks electrical grid, is continuous duty and is ON when the key gets switched ON. I've had those start to go bad too. There is a lot of power that goes to the glow plug circuit and the relay points will arc with the power. The relay plunger might be still clicking and working, but the contact points aren't letting the power thru. This affects the entire electrical system.

[rangerrattler]

Nov 11, 2014 5:54:11 GMT -5 fatguppy said:

You don't say if you charged the batteries or boosted/jumped it after one of these events? Also check the relay that is located on the drivers side fender well. Its tucked over by the air-cleaner and hides from view. This relay provides power to the entire trucks electrical grid, is continuous duty and is ON when the key gets switched ON. I've had those start to go bad too. There is a lot of power that goes to the glow plug circuit and the relay points will arc with the power. The relay plunger might be still clicking and working, but the contact points aren't letting the power thru. This affects the entire electrical system.

Ahh Very good point. I was thinking about this relay in the middle of the night..And yes, I tested earlier (back when the ground was different but the symptoms the same) jumping with my powerstroke and the same results occurred. So is this relay a part I can still buy, or is it something that has to be cleaned or rebuilt etc?

Thanks to all of you for the insight!

[fatguppy]

I can't remember if you can drill the rivets out from those relays or not. You should be able to still buy this relay or at least a heavy, continuous duty solenoid/relay from NAPA or someone. It's nothing really special. If you test it with a multimeter, it might indicate that it's passing the proper voltage, so make sure you test it with a heavy load on it.
I hate electrical problems and generally just tend to replace stuff like this if I have any doubt. This relay is a wear item for sure, eventually, if not right now, it's going to give you problems. If it's the original relay ..... just replace it with a new one if it's not rebuildable! It's easier to replace now, than when you're stuck somewhere in the middle of a cold, winter night.
Let us know what you find out.

[DieselDangerRanger]

That 'clunk' followed by a period of 'dead' is exactly what I experience with the poor connections on the battery terminals. The solenoid might be part of the problem. Try jumpering the batteries with the starter side with a hefty cable before cleaning up the battery posts. You might eliminate the battery connections and grounds as suspect this way. But again it sounds just like my bad terminals.

There needs to be frame grounding. Look to see if there is another ground cable you overlooked going to the block. Where are you located? is it cold there?

[rangerrattler]

Nov 16, 2014 8:58:21 GMT -5 DieselDangerRanger said:

That 'clunk' followed by a period of 'dead' is exactly what I experience with the poor connections on the battery terminals. The solenoid might be part of the problem. Try jumpering the batteries with the starter side with a hefty cable before cleaning up the battery posts. You might eliminate the battery connections and grounds as suspect this way. But again it sounds just like my bad terminals.

There needs to be frame grounding. Look to see if there is another ground cable you overlooked going to the block. Where are you located? is it cold there?

OK now I'm getting a bit confused..I was told by my mechanic friend that an engine block ground is always better, and he was very alarmed that an electrical current was being obtained through the body when the cable from the drivers side negative was grounded to the front body (near the radiator support, is that factory?) And the problem seemed to be "fixed" when all the terminals were cleaned up (they weren't bad at all anyway) and we reattached that black cable to the block, all was good.

The neg on the other battery is also grounded to the block on the other side. Is that not right?

I'm in Western Oregon. It has been cold at night, but only mid 20s and low 40s in the afternoon, like when I tried yesterday and all was good.. now the system seems to be working. I haven't gotten it to repeat the problem..yet! But I sure as heck ain't going anywhere till I get this all right..thanks again, gang..

[gradyc]

Grounding the batteries to the block is always better for the starting system but it is also necessary to have a good body ground for other parts of the electrical system to work properly. Having the batteries grounded to the block and then a good ground from the block to the body is the best.