• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

5.7 Hemi Engine swap on 70 RR (Project)

Thanks for your help Catfish, but I think I have my alternator problem solved. Now I have a no start issue. Before sending the PCM off I got under the hood with my test light and meter, because I had that one relay with only one power on it (relays always have two powers). I took the cover off the bottom of the fuse/relay box and traced the wire - it went into the wiring harness and ended with a tag on it saying AC - so this relay is not needed because I have the AC run on a independent relay. Everything else looked OK, but I check this little black looking fuse on the top of box. Found part # F57B-14A604-A on the "diode", not fuse (I always heard a bad diode would make your light pulsate). Found out you can only get continuity on a diode in one direction and you have to switch meter leads to test in the right/both directions - I'm getting nothing in either direction. So I finally got a hold of Mopar tech. support and talked to Don (https://www.moparproshop.com/customer_support) - nice guy, spent a lot of time with me. Told me to take my PCM out and take it to the dealer to be analyzed (when you analyzed something it cost more than if you just check it). Don also lead me to a wiring diagram.

PCM_diode.JPG


Not exactly my fuse box but close to what I have. If you notice on top, left of the relays is the "PCM Power Diode" (bingo, maybe). I tried to get one at the auto part store, nothing. I can order one on Ebay/Amazon but 2 week delivery times (but still trying). I think I'm getting close.

diode.JPG


It would be wonderful if I didn't have to spend $2300.00 on a new PCM/wiring harness/gas pedal combo, not to mention a new intake and throttle body! XXXX'ing my fingers this $8.00 diode is the fix.. Have to be careful what roads you go down...
 
Last edited:
Caterpillars said:
Thanks for your help Catfish, but I think I have my alternator problem solved. Now I have a no start issue. Before sending the PCM off I got under the hood with my test light and meter, because I had that one relay with only one power on it (relays always have two powers). I took the cover off the bottom of the fuse/relay box and traced the wire - it went into the wiring harness and ended with a tag on it saying AC - so this relay is not needed because I have the AC run on a independent relay. Everything else looked OK, but I check this little black looking fuse on the top of box. Found part # F57B-14A604-A on the "diode", not fuse (I always heard a bad diode would make your light pulsate). Found out you can only get continuity on a diode in one direction and you have to switch meter leads to test in the right/both directions - I'm getting nothing in either direction. So I finally got a hold of Mopar tech. support and talked to Don (https://www.moparproshop.com/customer_support) - nice guy, spent a lot of time with me. Told me to take my PCM out and take it to the dealer to be analyzed (when you analyzed something it cost more than if you just check it). Don also lead me to a wiring diagram.

View attachment 970033

Not exactly my fuse box but close to what I have. If you notice on top, left of the relays is the "PCM Power Diode" (bingo, maybe). I tried to get one at the auto part store, nothing. I can order one on Ebay/Amazon but 2 week delivery times (but still trying). I think I'm getting close.

View attachment 970037

It would be wonderful if I didn't have to spend $2300.00 on a new PCM/wiring harness/gas pedal combo, not to mention a new intake and throttle body! XXXX'ing my fingers this $8.00 diode is the fix.. Have to be careful what roads you go down...
Click to expand...

Received the new diode and it is testing the same as the old. No continuity either way but when I put power on one side I get 12v on the other (only in one direction). Not the $8.00 diode...
 
Update; After a few days of frustrations and learning more about PCM's then I ever wanted to know, I decided I was going down the wrong road. I was in the process of ordering a new PCM but everyone keep asking what my VIN number was. After explaining nobody seem to want to help (or maybe they don't know how). Can't tell you how many companies I left messages with and nobody returned my calls. The PCM, wiring harness world seems like a secret society that doesn't want to give out to much information. The Mopar people referred me to a company (Arrow Racing) that supposedly did all their crate engines PCM's but they are out of business, I guess. Mopar's answer to everything was "take it to the dealer", and the dealer asked "what is your VIN number. What a circle jerk!
My son convinced me to go back to the original problem, so I put the wiring harness, fuse box and PCM back the way it was. Then I unplugged the alternator's field wires and it started (by the way, I burnt out another alternator - 5th one - thanks goodness for O'Reilly's lifetime warranty). I had the ignition wire hooked up to both the alternator and the new wiring harness, so I separated them, same result. Now I think I'll put a toggle switch to battery and separate it from the ignition switch. New alternator runs a little warm and pulsating continues.
 
The separate toggle switch solve the problem. It operates the fuel injection and power relay which sends power to the Pcm. The ignition wire circuit goes to the field wire on the alternator. Everything seems to be working great so I'm calling the conversion part of this project done. Still have a few things to do like a headliner and getting the window tinted. Then just some odds and ends. Anyway two years - some good times and plenty of frustrations. Hope this helps some nut out there make it a little easier, and thanks to all who help me with the many problems I had. Now lets go for a ride....
Music by Caterpillars

 
Last edited:
Thats awesome, I need to go through all of the pages and see how you did it. I am thinking of putting a 5.7 in a 71 Charger I just bought. I'd like to understand what is needed to put a 4 spd behind one (A833) as well as the electrical aspects.
 
70chall440 said:
Thats awesome, I need to go through all of the pages and see how you did it. I am thinking of putting a 5.7 in a 71 Charger I just bought. I'd like to understand what is needed to put a 4 spd behind one (A833) as well as the electrical aspects.
Click to expand...
If you need help let me know...
 
70chall440 said:
So the crate motor came with a flywheel that put the starter on the passenger side?
Click to expand...
Yes, if I can remember right. It uses a Challenger starter so the setup is for a Challenger. Lots of crates are setup for truck and the starter is on the drivers side. Also, make sure the ring gear is on the correct side of the flywheel or you will be pulling the tranny after you think your all done.
 
Thanks. I am pretty sure this engine is for a Challenger (as per the PN). I need to see a picture of how the flywheel is supposed to be.
 
70chall440 said:
Thanks. I am pretty sure this engine is for a Challenger (as per the PN). I need to see a picture of how the flywheel is supposed to be.
Click to expand...
Copy of my post on page 2;

"Well got my answer from Holly/Quicktime. There are two flywheels for the 5.7 and most likely the 6.1 and 6.4. The trucks motors have the starters on the drivers side and the ring gear on the flywheel is on the side of the tranny. Car motors have starter on passenger side and the ring gear is towards the motor. Make sure you check this because the crate motor that I have has the truck flywheel, and I have the "8076" bell housing which puts the starter on the passenger side. This is very important because it all bolts together and everything looks great until you try and start it. Now I have to take it all apart and replace the flywheel - what a bummer...."

I don't know if this post is correct or if someone just put the ring gear on wrong. I talked to the person that set up the flywheel and he told me it was requested that way for some reason. It would be interesting to see if the truck motor or the set up with the starter on the drivers side has the ring gear towards the motor.

If you happen to have a flywheel with the gear on the wrong side don't do like I did and run out and buy a new one for over $300. It's not that hard to change them around.


Here is my old/new flywheel - notice the gear is towards the tranny side. By the way if someone needs a good deal on a flywheel let me know...

fly1.JPG
fly2.JPG
fly3.JPG
 
Thank you very much for posting that, I had read your thread but that video really helped.

Seems that we are going to opposite problems which will require the same procedure. I am not sure if I will do this or get another one, I realize it seems foolish to spend money needlessly but I need to do a lot more research to determine what I need to run for a pressure plate and clutch as well and I need to make sure they will work with whatever flywheel I have.
 
oops, didn't do that with Road Runner. Will see if it will match - pictures to follow.
IMG_7342.JPG
 
Sold to Melvin in Phoenix AZ. He's a good guy who seems to be a perfectionist when it comes Mopar's. He's going to take the Roadrunner to the next level. Hope he will post the results here.
 
Caterpillars,
So what wiring harness are you using that has a tach loop included?




For Mopar's AutoMeter said to cut each individual coil and rewire it through the adapter (shown above). I couldn't believe this setup so I called their tech. support and they told me it was the only way they could get it to work. I asked about the "tach. loop" that was on my wiring harness, and was told that mopars don't have a tach. loop or at least they have never seen one. I was ready to abandon ship but thought I would try to do something with the tach. loop. I cut the tach loop in half and measured the voltage on each wire with the ignition on - one wire had voltage and the other not. Connected the red wire to the loop wire with voltage and connect the red/green to the other. Hooked the grey to the "tic toc" tach wire and the black to ground. Turned the car on, presto.
 
PlumCrazyChris said:
Caterpillars,
So what wiring harness are you using that has a tach loop included?




For Mopar's AutoMeter said to cut each individual coil and rewire it through the adapter (shown above). I couldn't believe this setup so I called their tech. support and they told me it was the only way they could get it to work. I asked about the "tach. loop" that was on my wiring harness, and was told that mopars don't have a tach. loop or at least they have never seen one. I was ready to abandon ship but thought I would try to do something with the tach. loop. I cut the tach loop in half and measured the voltage on each wire with the ignition on - one wire had voltage and the other not. Connected the red wire to the loop wire with voltage and connect the red/green to the other. Hooked the grey to the "tic toc" tach wire and the black to ground. Turned the car on, presto.
Click to expand...
It was on a Mopar create motor
 
You must log in or register to reply here.

Similar threads

S
74 charger engine swap
Replies
8
Views
767
ckessel
ckessel
fontleyroy
TKX 70 Charger
2
Replies
21
Views
1K
fontleyroy
fontleyroy
jobenz
FOR SALE Mopar 833 Hurst Competition Modified 4 Speed Shifter, $900.00
Replies
0
Views
511
jobenz
jobenz
W
440 still won’t budge. 70 RR project.
2
Replies
20
Views
2K
coloradodave
coloradodave
M
1970 charger bad vibration at 100mph +
Replies
3
Views
437
Richard Cranium
Richard Cranium
Auto Transport Service
Back
Top