Fmtv no more dual voltage

jasonn

Member
45
0
6
Location
balto. md
ok i have had nothing but problems with this dual voltage stuff and I'm thinking about losing the 12volt side as its all lights except starter switch all lights on my truck are led omni volt anyway. does anyone have any thoughts about this? or has anyone done this already?
 

Suprman

Well-known member
Supporting Vendor
6,714
114
63
Location
Stratford/Connecticut
I dont see why you cant convert everything on a first gen truck. You would loose the 12v trailer control. Have to change out the light flasher. On the power board there is one row of 12v circuits and one row of 24v so its easy to figure out what runs off each voltage.
 

Suprman

Well-known member
Supporting Vendor
6,714
114
63
Location
Stratford/Connecticut
12v. Trans control is 24v. You could use a small step down converter to run 12v for ctis and other small accessories like phone charger.
 

tennmogger

Well-known member
Steel Soldiers Supporter
1,410
106
63
Location
Greenback, TN
Since you have to have two batteries in series, you could go 24v only and power the 12v circuits (as they exist with no conversions) with the two batteries and a Vanner (or similar) battery equalizer. The Vanner would ensure the two batteries were treated equally so there is not the old problem of tapping between the batteries for 12v, (which without the Vanner equalizer causes an imbalance).
 

coachgeo

Well-known member
3,166
231
63
Location
North of Cincy OH
Some of the mraps are set up this way.
Is it possible the original reason they went with dual voltage was to avoid using a converter that could be affected by an atmospheric electrical magnetic pulse (be it man made or natural). Once they went to engines with CPU's then they would have had to some degree (though probably not much) give up on that .... but the dual volt alternator system just remained cause it was already there and in most part worked fine.
 

Nukizer

New member
15
3
3
Location
Norwich, CT
12v. Trans control is 24v. You could use a small step down converter to run 12v for ctis and other small accessories like phone charger.
Trans controller is 12v/24v. It works with either voltage. I am converting my 2003 M1078A1 to just 12v. The 12v starter is a Delco 39MT #8200433, and the alternator will be a 22si.
 

Ronmar

Well-known member
699
282
63
Location
Port angeles wa
The Allison ECU voltage alarm points are programmed for 35V hi and 10V med-lo, 8V low, 7V ECU shutdown, but there is a note in the Allison troubleshooting manual talking about a specific 24V VIM this makes sense as the relay coils(like for the exhaust brake) are powered by switched input voltage so they have 24V relays in them. I think it may also have a 12V relay in it for neutral lockout, there is a 12V relay listed in the 24P manual as a part in the 24V VIM.

A little research and I found a different P/N for the two VIM’s
For WTEC II, the 24V LMTV VIM is P/N 29509889 (parts descriptions also call this a regulator)

The 12V VIM P/N is 29509886.

if you google these P/N’s you will find pics showing they have labels for 12V and 24V...
 
Last edited:
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks