Cucv electrical meltdown

[JAD561]

Well, my son took our 84 M1009 on a trip to PA, and had a major electrical problem. Long & short of it is this, He shut the truck after his ride. Two hours later he started it. The volt meter dropped to yellow, and he said the starter was screaming. He shut the ignition down, and the truck continued to run until it sputtered out a few minutes later. He said there were sparks comming from the rear battery. I told him to disconnect the front battery positive. He said the battery had power going thru it. I told him to pull the starter relay. He did, and at that point there was no longer any power going thru the batteries. I had him call a local bus depot. They replaced the starter with a 24v replacement. (we had an extra starter relay, so my son changed it) when they tried to start it, same thing happened.
This time a battery terminal & cable melted, and the fusible links on the alternators burned. The bus mechanics suggested converting to 12 volts, because in thier minds the 24 volts were back feeding thru the system. which I do not want to do. While checking posts, I found numerous one with similar problems, and a recomendation to do a "Dog Head Relay Conversion". What my question really is, to anyone who has experienced the same, is, does this sound like the relay is the problem ? I am 150 miles from my son & the truck, and we are limited by time & distance. Are there any other things I should be looking at, besides this relay, and the burned wires ? Any help or direction would be appreciated.

 

[antennaclimber]

Where in PA is your son?
Perhaps there will be a SS Member nearby that can help.

 

[raiburn]

1st, It needs the Doghead Relay Mod.
I think both relays used are bad.
Sounds like other stuff is fried now because of it.
Your going to have to go get it, These type of repairs need to be done on home turf.

 

[JAD561]

The truck wound up being towed to Pocono Transportation. Before I came up, I printed evrything that I could find on the Doghead conversion. I decided to have them do it, since we were not hame, and did not have a suitable place to work. They did the conversion, as I instructed, along with the diode that was recomended. In addittion, the fusible links that burnered were not on the alternators, but on the glow plug relay.They replace the battery terminals, and the fusible links, in addition to the conversion. They said the whole thing started because a wire hit the valve cover, and burned thru, causing a short & a chain reaction. Sounds plausible, but I'm sure it really started with the relay. The truck seems to be running ok, but there is a kind of bump or knock when first starting. after going thru what we went thru, I would recomend doing this conversion before you experience a problem. We still have to drive back to NY. hopefully there will be no further problems.

 

[JAD561]

Well, I thought the problems were over. We got the truck home, And it it sat for 2 weeks. Tried to start it yesterday. The replaced starter started winding, and a fusible link burned. I pulled the solenoid that they used for the replacement, and saw that they DID NOT use the one that was listed for use with the DOGHEAD conversion. I replace the fusible link, tried to start, and the link burned up again. I ordered the solenoids from Napa, but now I am wondering, Could they have put in a 12V starter, or a 24 V that was not intended for this type of use ? when I get the correct solenoid, should I also just bite the bullet, and replace the starter ? This is getting to be a frustrating issue, seeing my M1009 just sitting there, not running when I need it to. I don't know what to look at next. Any suggestions ?

 

[dstang97]

I did the same thing to my truck. I could not tell if my starter was 12v or 24v. It happened to be 12v. I hooked up 24v to a 12v starter and I had to run and rip off the battery connection. If I were you this is what I would do. leave it 24v. Find a OEM starter and have it rebuilt. Replace/ check fuisable links. Buy the exact same relay as listed in doghead relay. Check all wires so they are not damaged and go from there.

 

[dstang97]

A lot of people ( bus company) does not know the elec system in CUCV's. You are better off reading up on old posts and fixing it yourself.

 

[RedHeadTarn]

I did this relay mod and have not had any problems until my starter went out and melted my battery cable as well. Mine happened because the bad starter was drawing almost 500 amps. I wired in a simple switch in the line that goes from the relay to the starter just in case the relay fuses shut, I can hit the switch and kill power to the starter. Put it in an out-of-the-way place under the dash and you have a simple theft deterrent. Hard to steal a truck that only goes "click" when you turn a key...

 

[Matt65]

I wired in a simple switch in the line that goes from the relay to the starter just in case the relay fuses shut, I can hit the switch and kill power to the starter. Put it in an out-of-the-way place under the dash

Do you have any pics of your set up? It sounds like you won't have the same issue again.

 

[RedHeadTarn]

I don't have pics, but I just did Dogheads relay mod just as instructed, including the diode. And then tool the wire going from the relay to the starter and put in a on/off switch that I mounted directly under the steering column. It's easy to get to in a hurry but when sitting in the drivers seat the bulk of the steering wheel column hides it from view. It's also not labled so anyone trying to hotwire the ignition will be hard pressed to figure out what it does. It's also a fairly insignificant looking switch, so not likely to attract any attention.
I will try to take some pics, but I can't seem to upload pics from my phone to the website, so I might have to jury-rig some computer connections to get them here.

 

[warriorbob]

i had this problem with mine... The civi that owned it previously jjacked it all up... Friend of the family thats rebuilds cars found that numorus problems caused this. My driver side alt wasnt grounded, we replaced the starter and solenoid, and finally he went into the wireing harness and it was the starting relay, along with various other worn out parts