starter relay question

[sht2kll]

Howdy all: I have been having a intermittent battery drain problem on my M1008. I finally think I found it. Lately I have been disconnecting my negative battery lead (truck converted to 12v) so I would not come out to a dead battery. I had got out my multimeter and the wiring diagrams one day and was checking all the power wires I could find to see where my draw might be. It is hard to troubleshoot something that is intermittently acting up. Today I came out, touched the neg. battery cable to the post and heard a "click" down near the starter. Immediately a little light came on in my head that said," Doghead relay mod needed". My question to anybody is, Why do they have this relay that is under the dash? Civi diesel vehicles do not use them, do they? Has anybody eliminated this relay in their M1008? I would like to get rid of this thing as it seems to troublesome part as is the GP controller, which I am thinking of eliminating also. A straight manual GP control would make my M1008 world a whole lot better. Thanks for any help. You guys always seem to come up with great ideas. Tom

 

[Ghost2012]

IIRC The CUCVs have a relay that cuts power to certain systems. I noticed my radio and other accs, resetting each time I turned off my truck.

 

[M1008driver]

From all my reading here the doghead relay is not needed if you converted to 12 volt, except some leave it that way as an extra precaution.

From my own experience if you are having an intermittent battery draw down and when you touched the negative cable you got a click, you have a bad connection or short that needs to be found. It will leave you stranded if not found and fixed. I hope I gave out good information because I just went through something similar.

 

[boomer431]

The starter relay is not needed on a 12v conv. Its purpose is to convert the 12v signal from the ign switch to 24v to the starter solenoid. Unplug it ,cut the purple and purple /white wires and join them together.

 

[Warthog]

Only time I question "removing" stuff from an MV is future resale. What about the guy you sell it to and wants to take it back to stock? I have spent $$$$ putting trucks back together.

Do the Doghead Relay update. It only costs a few bucks. And it does help in a 12v conversion as the stock relay was just not up to the job.

 

[boondock]

I wholeheartly agree with Warthog- big dollars can be required to remove 'improvements & upgrades' when attempting to return a vehicle to stock configuration. Been there & done that.

 

[sht2kll]

Thanks for the help. I agree about keeping things stock, but when a system is faulty by design or the original parts are no longer available, then fixing the problem is in order. As far as I know civi diesel trucks and blazers of that year do not use them. I do not see how a secondary starter relay would be of a benefit. The GP controller is the same problem. I know that a couple other circuits are linked to that so if I i modify that I will have to take that into account. I would make make notation on the wiring diagrams that I have to show the changes. I would also not just be cutting and bandaging the wiring I can change the systems and still leave them so they can be rebuilt without too much hassle( the nice thing about being an A&P for so many years). If anybody were to buy my rust bucket and wanted to make it original, who knows why they would ever want to, they could. Tom

 

[M1008driver]

Today I came out, touched the neg. battery cable to the post and heard a "click" down near the starter.

You still need to find the loose connection or short.

My understanding of the doghead mod is it will save you big repair cost from a known problem that can occur. $9.99 at Oreilly's compared to a new starter, batteries, and cables amongst other things that will melt from a stuck starter. Furthermore, because your vehicle is some kind of modified 12 volt system nobody here can really help you. I hope you are a good mechanic or know one...

It's your CUCV. I hope it works out for you favorably.

 

[Disciple]

Just being diligent here, but are you sure the "click" came from down by the starter? Is it possible that it could have been your glow plug relay? I had an odd battery drain, was killing my batteries, etc. Turns out the GP Relay was stuck closed and my GP's were ALWAYS ON! Just one more thing to check. Myself, I now have my GP's on a manual switch as a backup to the GP Controller card and my starter on a push-button, but I haven't converted to 12v nor will I.

 

[sht2kll]

Howdy. Yes the click came from the starter relay (on the starter) . I was outside the truck next to batteries when I heard it. Changing it to 12v is not mysterious thing. There was a real good article I found that the conversion was done on some forestry vehicles. It has been working for about 6 months now. I am going to disconnect the the relay in the truck. That will eliminate one more thing that can go wrong. Thanks again for all the help.