HDJ81 24v Starting System Issues (3 Viewers)

[AirheadNut]

After a week and a half of sitting in a garage my HDJ81 is refusing to crank. Everything seems to work normally until I turn the key to the "start" position, when a bunch of relays can be heard clicking but the starter doesn't even try to crank. So far I have tested the following:
-Starter motor; will crank the engine over fine when a lead is run from the battery to power the "magnetic switch" (starter solenoid) and the key is in the start position.
-12/24 volt converter relay; I have performed the continuity test from the FSM
-Starter relay; again, I have tested according to the FSM
-Continuity from the starter relay to the starter solenoid
-24v at the starter when the key is on "start"
-Fusible link continuity is good
-Voltage coming into both plugs for the starter relay

I even got the engine to start when I ran a wire from the battery to the starter solenoid, but when I turn the key nothing happens. The only thing I can imagine is that there is a little too much voltage drop across all of the relays in the starting system, and by the time power gets to the starter solenoid there isn't enough to click it on. Any thoughts? Have I missed something?

 

[BCR4619]

does it use sit there and click and not turn over? check your terminals on your battery? my stock lead ones were loose and caused all sorts of problems for me until I looked under the hood while I tried to crank and say smoke from the terminal.... further investigation showed they were loose, cleaned them up and put some grease on it and all has been fine, replacement is on the list!

 

[AirheadNut]

I have checked all the terminals, they seem good and tight. The starter will crank just fine if I run a 12v wire straight to the solenoid, but it doesn't get the 12v from the ignition to activate the solenoid.

 

[AirheadNut]

I also forgot to mention that I have checked all of the fuses in the vehicle; they were all good.

 

[vwluv10338]

Sounds like wiring. I chased starting problems on my 2h for a year before I found excessive resistance in my ground wire running to the block.

 

[JimmyPrado]

Sorry to hear this Air, bummer. Good luck. I'm thinking you are on to it regarding the drop. If ground, then a hotwire from battery wouldn't do it. I hate electrical. It's Kinda like calculus!

 

[AirheadNut]

True, I hadn't considered that the ground would work if the hotwire worked. I am going to test voltage at the various plugs throughout the system this afternoon and see if I can find the problem. I am also going to clean all the plugs and perhaps add a little dielectric grease to them to see if that makes any difference.

 

[AirheadNut]

SUCCESS!! I tested the voltage at the starter relay, and again at the plug down at the starter (between the relay and Terminal 50, and got ~12 volts at both places. I removed the short pigtail that goes from Terminal 50 to the plug at the starter and throughly cleaned it (there was some oil on it that had drained down from the oil filter). After putting everything back together it fired up just fine! Fingers crossed it stays that way I think that there was some oil in the plug and it was producing a small amount of capacitance, effectively reducing the voltage at the solenoid.

 

[JimmyPrado]

Is capacitance a word? Congrats!!

 

[amlnz]

SUCCESS!! I tested the voltage at the starter relay, and again at the plug down at the starter (between the relay and Terminal 50, and got ~12 volts at both places. I removed the short pigtail that goes from Terminal 50 to the plug at the starter and throughly cleaned it (there was some oil on it that had drained down from the oil filter). After putting everything back together it fired up just fine! Fingers crossed it stays that way I think that there was some oil in the plug and it was producing a small amount of capacitance, effectively reducing the voltage at the solenoid.
View attachment 1404527

Hey mate,

What's that book? Could come in handy

Cheers,

Allan

 

[AirheadNut]

I am actually not sure what book it is, I got those photos courtesy of @mudandrock

 

[mudandrock]

I am actually not sure what book it is, I got those photos courtesy of @mudandrock

1990 1pz 1hz 1hdt engine FSM

 

[AirheadNut]

Well, after a couple of weeks of working great the system went on strike again today. I have re-cleaned the connection and added dielectric grease, but no luck. Not sure what to do at this point.

 

[AirheadNut]

I have had another thought. Could it be that the starter solenoid (magnetic switch per the FSM) has some corrosion on contacts inside? It has been very damp here, and I wonder if that could contribute to causing a poor internal connection in the solenoid.

 

[mudandrock]

Does your starter relay engage when you send power to just it?

 

[AirheadNut]

Yes, the starter relay works, I have tested the whole system up to the starter itself.

 

[mudandrock]

When you hot wired it, was it with power directly to the starter itself?

 

[AirheadNut]

Yes, I ran power directly from the battery (12v) to the small wire on the starter (the one that comes from the starter relay). It seemed to crank just fine when I did that.

 

[mudandrock]

I'd try that again and then work backward according to your diagram. Or as you said, Your contacts inside the starter could be corroded.

 

[Alic]

I will write my experience with about 10 starters. I do it on difficulty and time consumption ascending.
First)
I have three events of starter mulfanction connected with starter ralay.
Relay clicks, i heared it, but no contact was. That is it was one time and no another time.
Try to clean up realy. It takes you 10 minutes, but you will be shire that the problem not in it.
Expand cap of relay and clean up contact with small sandpaper. Check it for corrosion and see if it works.
Inspect and clean all contact on its plugs.
See if relay's power contact have +12v constant.
Then try to start engine and see if ralay's signal contact have +12v

Second)
Take thick wire and add it from the right (batt - ) to engine.
Third) touch 12-24ralay with your nail, try to start engine and feel if it works.
Forth) try start engine and see if bottom contact of starter has 24v

You should try all that only when starter do not crank ones again. Do not try that when it is all ok - it is useless.
If all good, then disassamble starter. May be it is like that.

indeed all manipulations takes you about half an hour.