ls swap questions

[feller]

ok firts off, this is not a swap for a truck. but still fits in this fourm i think... any way. i have an 86 monte carlo that me and some friends swapped the old 305 for a 350 to get some power out of the old girl, but because of the liquid courage we had in us we decided not to unplug any of the factory wiring harness, but rather cut it all to peices. (not a good idea)!!! but you live and learn. so a friend and mechanic now tells me that if i want the alternator to charge and the factory guages to work properly i will now need a complet wiring harness. (good luck finding one).

now for the ls questions. if i swapped an ls say a 4.8 or 5.3 with all accesories and say gm's stand alone controler would this solve my charging and any other problems that i may have without a factory 1986 monte carlo harness, while giving me more power,fuel econ, and making the vehicle more dependable. if so is it reasonable to think i could do all this for around $1500? any help or expereance with the stand alone computer is appericated.

[clinebarger]

If you or your friends cant fix the problems you caused with the 350 swap, I highly doubt you could tackle a LS swap. I can help you straighten up the mess. There is a big harness coming from the driver side of the car Over the brake booster....Where did you cut that harness? Pics would help.

[Robznob11]

In short yes the stand alone set up would fix it all. hence the name stand alone. now you can get a harness pre made and there is no thinking to it. or you could rewire your own and as he said it may be a challenge if you cant fix the problem you have but you have full directions and pics on lt1swap.com witch im sure you do not have for your situation right now. there are other obsticals to over come like header and oil pan clearances. good luck and aslo some more info on the situation you have now would be nice. it an 86 is as simple as the older chevys. there is really not much to the wireing and it looks more daunting than it really is. usually there is not much to an altenator on wire going to the battery and the others usualy light up your gauge. depending on what type it is.

[feller]

well im not sure where any of the wires were cut, but i do know that there were some that got cut less than 6 inches from a plug/conector. whoops!!!!

i personaly havent looked and tryed to sort it out yet i was more worried about mechanical problems that i was having, like the headders vs. manifolds, chose headders and they made the floorboards hot so had to go back to manifolds.. you know stuff like that.

the original harness means nothing to me, i mean i just want the car to run dependably, like if my grandma wanted to drive it for a day then she could without worring about her getting stranded, i say grandma because her aunt bought the car new. it only has 58k on the odometer and im sure it hasnt rolled over.

[Clyde65]

Get pics of the connectors that were cut and where they go.

seems to me if you have the connectors , you should be able to splice and soder the two pieces together.

[feller]

yeah i dont have the conectors anymore they left with the 305, off to the junk. and the 350 is out of an 80 truck, my biggest question was if i did an ls swap would i need the wiring that is only partialy there, im tryn' to get away from the wiring mess i have now make it look cleaner and safer and more dependable, mabey drive it every day? who knows.

[BR3W CITY]

No, you wouldn't need ANY of the stock engine harness. The LS engines (when coupled with a cc'd tranny and pcm) are essentially stand alone. You could put it into something like a 29 model a (with no real factory harness to speak of) and have it work fine.

When you buy a harness, it will have every connection for the engine, tranny, and all sensors and accessories (like DBW pedal, fan, etc). Any connections that you terminate are +12v power and grounds and thats really it. You don't even need a factory wiring diagram at all.

The only stock wiring you would really access would be the ignition switch, and body wiring like brake lights etc. It sounds like the body wiring is in tact, so in that case you would be good to go.

My truck was a 6 cylinder, then became a small block twice, then got an LS motor. The wiring had been changed a few times, and the LS install gave me a clean slate to start from, since no wiring is really re used.

[feller]

ok br3w city. thats what i wanted to know. as far as i know the factory gauges are mechanical, or i got lucky enough to wire them up right all except the oil press. but that is more a sending unit problem i think, any way will they work fine with this too? i want to keep them if i can.

[BR3W CITY]

check the lsx faqs we have, theres alot more info in there too!
Stock gauges can be kept, depending on what kind of input they take
Mechanical speedo will need a Cable X or similar converter
Oil pressure will work fine if its mechanical (ie tube with oil in it)
You'd need to add a sender for temp on an LS engine
Tach can work if the PCM is changed to put out 8cyl signal. There is more on this in the faq

[feller]

thanks alot, i think im sold on the idea!!!