12 volt conversion starting problem

[hendrix256]

i have converted my m1009 cucv to the 12v system and was wondering if the second battery is needed or can you start the truck with just one. the reason for this is that i have the new 12v starter installed and everything works but the truck is really sluggish to turn over and i was wondering if it was the cca or the starter needed to be shimmed

 

[Warthog]

Welcome to the site.

A little house keeping first. Per the rules you agreed to you need to change your profile to list the State of your residence. The United States is not a state.

How did you rewire the truck?

The compression on the 6.2L engines is high and the starter needs all the help it can get to spin the engine. Two batteries are highly recommended. In the civvy diesel trucks GM installed two batteries. Most diesels use two batteries.

 

[doghead]

Did you replace your starter with a 12 volt starter?

 

[hendrix256]

i rewired it as showed in the step by step shown on....http://www.roscommonequipmentcenter.com/nn10.pdf. but i only hooked up one battery as the parts i need are not on hand and was wondering if it was the low cca on the battery or that i need to shim the starter.

 

[hendrix256]

yes i replaced my 24v with a 12v because i cracked both of the housings on the old one

 

[m38inmaine]

All 6.2 diesel came from the factory with 2 batteries. Too bad you converted to 12v, you gave up one of the best features of the cucv, the 24v starter uses half the amperage of a 12v and makes starting much easier. Most new starters are the no shim type.

 

[doghead]

You need to measure the gear engagement clearance as outlined in the TM.

Otherwise, you are only guessing if it is engaging correctly.

 

[M1008driver]

You need two batteries wired in parallel. My truck is converted using the Roscommon method and it is the best thing I've done. The truck starts after sitting in the cold for a week or more. The beauty of the conversion is buying parts locally. The 1975 Cadillac alternator DL7157 fits the PS, the two belts you need are stock for the civy K30 equivalent, and the starter is easy to find. By rewiring the old starter you will need to change the bracket if you ever do buy the new style starter.

Plus I get lifetime warranties on parts. My truck has not let me down yet and I could not say that for the 24 volt system.

 

[GPrez]

You don't say what the CCA of your battery is, but I use 2- 1000 CCA on my M1009 that is 12v and I have had no issues starting it even when it's 15-degrees out. With that said my M1028 that is still 24v does start easier.