89 Hmmwv duramax swap 24v system

kmf818

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i am doing a lb7 duramax swap on a 1989 hmmwv. i have the drivetrain in; new interior; engine harness is also hooked up. The only issue is the wiring i have to leave in for the body headlights brakelights turn signals sending unit ect. The system originally used 24v but the lb7 uses 12v. i heard from others that i would have to change out the bulbs from 24v to 12v and i would also have to get a flasher/relay i assume either for the turn signals or for the wiring of the truck. If anyone has any info or a place to buy parts i would appreciate it. in exchange i can give pointers on how to do this kind of swap without breaking the bank.
 

simp5782

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Its cheaper to just swap bulbs or lighting units along with a flasher relay for it. Flashers only have 3 wires going to them. We have to do this on the older trucks to run LEDs its just a 3 prong flasher. The truck doesn't know what it is it can be anything it wants to be. 12, 24,48,460volts.

Its cheaper to do lights and that's about it. If you have LED's they will work on 12v anyway since most of them are Omnivolts. Just simply replace your headlights with 12v ones.
 

kmf818

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Its cheaper to just swap bulbs or lighting units along with a flasher relay for it. Flashers only have 3 wires going to them. We have to do this on the older trucks to run LEDs its just a 3 prong flasher. The truck doesn't know what it is it can be anything it wants to be. 12, 24,48,460volts.

Its cheaper to do lights and that's about it. If you have LED's they will work on 12v anyway since most of them are Omnivolts. Just simply replace your headlights with 12v ones.
Where could i buy a good lighting unit with the flasher relay?
 

simp5782

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you will need trucklite Omni volts for LED turns and Tails. The Trucklite type 30s are the marker LEDs they are available from any truck parts place. Ebay has tons of 12v flasher units. Any generic one will work. Or actually any relay in general for 12 volts will work as long as its a 1 - p - 1 setup.
 

TOBASH

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Get a dual voltage alternator and wire two separate circuits [ie.: 24 V and 12 V]. Easier than swapping bulb and such, and dual voltage alternators came standard on many of our vehicles. Requires alternator and wiring harness conversion kit that also comes with new alternator mount.

Site sponsors and Fleabay have this stuff for reasonable prices.

Best,

T
 

Action

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Get a dual voltage alternator and wire two separate circuits [ie.: 24 V and 12 V]. Easier than swapping bulb and such, and dual voltage alternators came standard on many of our vehicles. Requires alternator and wiring harness conversion kit that also comes with new alternator mount.
Best,

T
Is our 200 amp alternator going to easily bolt to his duramax?
 

TOBASH

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Never said easy. I don't know the Duramax. He just fit a new power-train into his vehicle...odds are he can handle necessary mounting brackets.

It is a viable option
 

NormB

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i am doing a lb7 duramax swap on a 1989 hmmwv. i have the drivetrain in; new interior; engine harness is also hooked up. The only issue is the wiring i have to leave in for the body headlights brakelights turn signals sending unit ect. The system originally used 24v but the lb7 uses 12v. i heard from others that i would have to change out the bulbs from 24v to 12v and i would also have to get a flasher/relay i assume either for the turn signals or for the wiring of the truck. If anyone has any info or a place to buy parts i would appreciate it. in exchange i can give pointers on how to do this kind of swap without breaking the bank.


This post is useless without pictures. :D
 

jackson76550

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sealy tx
Ditch the 24 volt system all together. If you have swapped a d max in, id assume you have the knowledge to make all of that happen fairly easy. Lights, blower motor and wipers would be easier to convert that coming up with a dual voltage system
 
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