Need Help with Wiring. 71 Roadrunner

Thread Tools
 
Search this Thread
 
Old 04-07-2015, 06:10 PM
  #1  
Mopar Lover
Thread Starter
 
rcknrolfender79's Avatar
 
Join Date: Aug 2009
Posts: 528
Received 11 Likes on 10 Posts
Need Help with Wiring. 71 Roadrunner

Hey guys just got a new car today. Its a 71 Roadrunner 383 car. Its a project car and the gentleman I bought it from claimed the starter was bad. But after talking to him for a while it was clear he didn't know too much about mechanics. And as most of you know changing the starter on these cars is a monstrous pain in the *** especially with headers which this car has. So trying to rule every other possibility out before going through with changing the starter.

First off this car does have some wiring issues. First thing I noticed on the fuse block was that the terminal at the bottom labeled "Batt" has no wire going to it.. just a bare terminal. Also the terminal next to it labeled "Acc" has a wire on it that is cut at the end leading no where. I'm just wanting to make sure the starter isn't bad. Does either of those terminals need to be hooked up to just turn the starter? Also where do those 2 need to go to? Does the "Batt" Just have a wire going straight to the battery or does it need to go through the ignition switch first? And where does the "Acc" terminal go? I was thinking that one would probably come straight off the "Acc" position of the ignition switch.

The voltage regulator was bad and has been replaced. Checked the resistor on the fire wall and it seems to be in good shape as well.
Old 04-07-2015, 06:47 PM
  #2  
Mopar Lover
 
RacerHog's Avatar
 
Join Date: Jun 2013
Location: Monrovia SO-CAL (USA)
Posts: 10,388
Received 869 Likes on 848 Posts
You need one of these..... http://diagramonwiring.blogspot.com/...-complete.html


Battery Should be hot all the time....
Acc is run threw the Ignition Switch....

Problems with no crank...
Amp Gauge no good....
Seat belt lock out......
Neutral Safety Switch....
Ignition switch no good....
Broken wire....
Bad Relay......

Now get to the hunt !!!!!

Keep us posted....
Old 04-08-2015, 08:22 AM
  #3  
Mopar Lover
 
moparted's Avatar
 
Join Date: Oct 2009
Location: Mayfield,NY
Posts: 727
Likes: 0
Received 46 Likes on 46 Posts
thatbat terminal is an accessory terminal. not used by the factory
Old 04-08-2015, 11:21 AM
  #4  
Mopar Fanatic
 
DDodger's Avatar
 
Join Date: Nov 2014
Posts: 268
Likes: 0
Received 27 Likes on 27 Posts
If you are gonna have one of these cars you MUST get a service manual. You can find reprints, used originals and electronic ones. You can download an amazing amount of them over at MyMopar. MyMopar also has 3rd party wiring diagrams which are sometimes helpful BUT WHICH are not as complete as originals

You need to understand the function of your starting system and how to test it.

FIRST you need some tools, a multimeter, and some alligator "jumper" leads.

================================================== =================

First "quick" test is to make sure trans is in park or neutral, take a screwdriver and jumper across the starter relay under the hood. If starter does not crank, the trouble is........

Bad battery, bad cables, bad cable connections, or THE WIRE going from the "square" relay terminal down to the starter "or it's connections."

Get the car safe, jacked up if necessary, and under the car to where you access to the starter.

Clip an alligator to the large battery stud on the starter and jumper that to the small solenoid terminal. Does it crank?

If no, use additional clip leads to connect the multimeter from the large battery stud to the engine block.

Now jumper the solenoid again, and while jumpered, READ the voltmeter. You should have at least 10V, 10.5 or better is "better."

If it does not crank, post back here with reults and SOUND

The above trouble might be bad battery, bad cable connections, bad cables

I================================

If the starter DOES CRANK, in the two tests above, your starter is in the starter relay or the trigger wiring.

================================================

WHAT TRANSMISSION do you have? On automatic, one of the two "push on" terminal of starter relay goes "to ground" in park or neutral

On stick transmission, this same wire is grounded by the switch acted on by means of the CLUTCH PEDAL

Automatic? Hold key to start. Wiggle shifter from park to neutral. See if it tries to crank

Disconnect one of two "push on wires" on start relay. Hook you test light or multimeter to ONE of them, twist the key. Is it hot? If not TRY the other

Take the wire that is HOT with key in start and connect that to the relay. Pull loose the remaining wire. ON automatic, you can follow that wire down the firewall, over the bell to transmission.

Take an alligator lead and GROUND the exposed terminal of the relay you just unhooked. See if the car cranks with key

Yes? Trouble is in neutral / clutch switch terminals or switch or linkage mis-adjusted with automatic

No? Bad starter relay
Old 04-08-2015, 02:42 PM
  #5  
Mopar Lover
 
Coronet 500's Avatar
 
Join Date: May 2011
Location: Ontario Canada
Posts: 2,732
Likes: 0
Received 359 Likes on 333 Posts
Nicely done DDodger.
Old 04-08-2015, 09:19 PM
  #6  
Mopar Lover
Thread Starter
 
rcknrolfender79's Avatar
 
Join Date: Aug 2009
Posts: 528
Received 11 Likes on 10 Posts
thanks for replies gents. The starter will crank when you jump the terminals on the solenoid. I just did it the old fashioned way with a screwdriver. After getting everything stripped out of the car today I think I discovered a possible issue lol.. someone at some point thought it would be a good idea to just cut the wiring harness in half.. most of it anyways left most of the lights system intact.. Dont have any idea why someone would do this.. but anyways not much you can do about past stupidity except fix the damage it caused i guess. Anyways going to splice all the wires back together and see what happens after that. I'll get back to you guys.

I do have one question.. where is the starter relay located?
Old 04-09-2015, 08:32 AM
  #7  
Mopar Fanatic
 
DDodger's Avatar
 
Join Date: Nov 2014
Posts: 268
Likes: 0
Received 27 Likes on 27 Posts
Sorry I don't keep track of the various mounting positions, look around in the engine bay. The solenoid wire off the starter runs up to it.. But Mopar start relays are one of the most recognizable components there "is." Just like the popular Ford start solenoid used for decades. It will look similar to this unless replaced by a hack

Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Muswagon
Mopar Classifieds
0
12-08-2010 06:22 PM
67gtxclone
B-Body
4
03-19-2010 01:30 AM
Cal Lawton
B-Body
3
10-06-2009 03:16 PM
Dodge_Coronet1967
B-Body
7
03-05-2009 03:12 PM
wtim47
Cuda Specific Discussion
1
06-08-2007 04:51 PM



Quick Reply: Need Help with Wiring. 71 Roadrunner



All times are GMT -7. The time now is 04:58 PM.