Previous Thread
Next Thread
Print Thread
Switched from a MSD Digital6plus to a MSD 7531 and now no .. #2486495
04/22/18 06:44 PM
04/22/18 06:44 PM
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
S
Sammy Offline OP
top fuel
Sammy  Offline OP
top fuel
S

Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Start.
Changed to the correct MSD Coil #8261, and all new wires.
Programmed it into my laptop for start retard, rev limiter, shift light.
1st I didn't get a initial red light on the side of the 7531 then I realized on the main harness, I didn't hook up the small red 12v switched wire.
Now I get the red light but the car will not start.
Light blue to line lock, yellow to CO2 valve, Dark blue to brake switch.
Heavy red to battery, Black to a good ground.

I tried another 8261 coil that I know works and still nothing.
What am I missing and doing wrong?

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2486505
04/22/18 07:25 PM
04/22/18 07:25 PM
Joined: Feb 2009
Posts: 345
Arkansas
JoWeTu_6 Offline
enthusiast
JoWeTu_6  Offline
enthusiast

Joined: Feb 2009
Posts: 345
Arkansas
Sammy, I'm assuming crank trigger, have you checked your 8860 cable from the CG and verify fire at the plugs.
Are you running this box as a stand alone or through a MSD 7 ext..?

I hope you can sort it all out oh BTW
did you make sure theirs gas in it just kidding LoL LoL.

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: JoWeTu_6] #2486531
04/22/18 08:20 PM
04/22/18 08:20 PM
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
S
Sammy Offline OP
top fuel
Sammy  Offline OP
top fuel
S

Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Originally Posted By JoWeTu_6
Sammy, I'm assuming crank trigger, have you checked your 8860 cable from the CG and verify fire at the plugs.
Are you running this box as a stand alone or through a MSD 7 ext..?

I hope you can sort it all out oh BTW
did you make sure theirs gas in it just kidding LoL LoL.



Hi, no crank trigger at this time. I have 6psi fuel pressure and I see gas.

What's the CG?

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2486533
04/22/18 08:22 PM
04/22/18 08:22 PM
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
S
Sammy Offline OP
top fuel
Sammy  Offline OP
top fuel
S

Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
I going to put the old 8860 cable that I know works back on

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2486554
04/22/18 09:17 PM
04/22/18 09:17 PM
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
S
Sammy Offline OP
top fuel
Sammy  Offline OP
top fuel
S

Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Swapped out the 8860 and still no startup.
Where should I look next?
If I turn the key in the on position, I do see the red light blink, so I am definitely getting voltage to the 7531.
I am NOT using a ballast resistor FWIW.

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2486562
04/22/18 09:59 PM
04/22/18 09:59 PM
Joined: Sep 2003
Posts: 2,175
Duloc
T
The Shadow Offline
top fuel
The Shadow  Offline
top fuel
T

Joined: Sep 2003
Posts: 2,175
Duloc
Is the spark turned off or on?
Did you try grounding the white to see if you get a spark?

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2486663
04/23/18 01:31 AM
04/23/18 01:31 AM
Joined: Jan 2003
Posts: 20,149
Park Forest, IL
slantzilla Offline
Too Many Posts
slantzilla  Offline
Too Many Posts

Joined: Jan 2003
Posts: 20,149
Park Forest, IL
Are you using the factory ignition switch? The RUN wire goes dead when you switch to START.


"Everybody funny, now you funny too."
Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: The Shadow] #2486747
04/23/18 10:43 AM
04/23/18 10:43 AM
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
S
Sammy Offline OP
top fuel
Sammy  Offline OP
top fuel
S

Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Originally Posted By The Shadow
Is the spark turned off or on?
Did you try grounding the white to see if you get a spark?


What will grounding the white wire do?
I'm sure I don't have spark.

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: slantzilla] #2486748
04/23/18 10:45 AM
04/23/18 10:45 AM
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
S
Sammy Offline OP
top fuel
Sammy  Offline OP
top fuel
S

Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Originally Posted By slantzilla
Are you using the factory ignition switch? The RUN wire goes dead when you switch to START.


Yes factory ignition key to fire car up except years ago, the factory ballast resistor was removed.

I'm trying to figure out why the digital6 plus worked fine and now digital 7 it doesn't fire.

I sho7ld gave left it alone.
I didn't see in the instructions you can start retard with the digital 6plus.
I hate the kick back on start up.

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2486760
04/23/18 12:11 PM
04/23/18 12:11 PM
Joined: Jan 2003
Posts: 2,094
central texas
K
krautrock Offline
top fuel
krautrock  Offline
top fuel
K

Joined: Jan 2003
Posts: 2,094
central texas
the factory ballast was setup so you got 12v from the ballast in RUN or START on yr igition switch.
if you pulled the ballast off, then you need to wire both ign1 and ign2 (the Run and Start positions in your ign switch) to the 12v turn on lead on yr ign box...

Last edited by krautrock; 04/23/18 12:12 PM.
Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2486820
04/23/18 01:43 PM
04/23/18 01:43 PM
Joined: Nov 2015
Posts: 870
Missouri
J
jwb123 Offline
super stock
jwb123  Offline
super stock
J

Joined: Nov 2015
Posts: 870
Missouri
Use the MSD diagnosis test for the box
https://www.msdperformance.com/support/troubleshooting_techniques/

You should be able to trigger the box with a jumper wire, sounds like you just got a bad box.

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: jwb123] #2486919
04/23/18 06:13 PM
04/23/18 06:13 PM
Joined: Mar 2005
Posts: 1,581
N/E, Michigan
RATTRAP Offline
pro stock
RATTRAP  Offline
pro stock

Joined: Mar 2005
Posts: 1,581
N/E, Michigan
Originally Posted By jwb123
Use the MSD diagnosis test for the box
https://www.msdperformance.com/support/troubleshooting_techniques/

You should be able to trigger the box with a jumper wire, sounds like you just got a bad box.


Yup bad box IMO, Been There, I always check it with my old standard 6al
and it fires every time, there digital series has problems.

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2486949
04/23/18 07:34 PM
04/23/18 07:34 PM
Joined: Sep 2003
Posts: 2,175
Duloc
T
The Shadow Offline
top fuel
The Shadow  Offline
top fuel
T

Joined: Sep 2003
Posts: 2,175
Duloc

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: krautrock] #2486972
04/23/18 09:04 PM
04/23/18 09:04 PM
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
S
Sammy Offline OP
top fuel
Sammy  Offline OP
top fuel
S

Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Originally Posted By krautrock
the factory ballast was setup so you got 12v from the ballast in RUN or START on yr igition switch.
if you pulled the ballast off, then you need to wire both ign1 and ign2 (the Run and Start positions in your ign switch) to the 12v turn on lead on yr ign box...



Well the plot thickens, I rewired the digital6 plus and still nothing.
So I looked under dash to the ignition key switch and it looks like that one terminal has nothing on it another terminal has a blue wire going somewhere and then it looks like someone who owned the car before me wired 2 wires into one and one black, but the black is cut off about 12 inches off the splice.(Could this black wire go to ground by any chance?)
Where should these wires go to? I think I found my problem, because when I turn on the key I get the red flashing light.
I went right to the battery with the red to positive and black right to negative lug.
I might have cut a wire under the dash by mistake.

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2486988
04/23/18 10:02 PM
04/23/18 10:02 PM
Joined: Jan 2003
Posts: 2,094
central texas
K
krautrock Offline
top fuel
krautrock  Offline
top fuel
K

Joined: Jan 2003
Posts: 2,094
central texas
wiring schematic for your model should show you where the wires are, they go to the bulkhead and then come through and run to the ballast resistor. my cars wiring was terrible to i just wired the two in series at the bulkhead and ran that to my msd box.

the first thing i would do is figure out which terminals in the bulkhead are ign1 and ign2, and test them with a dmm on the engine side of the firewall...in the run and start positions. if you don't get the voltage at that point, you need to go under the dash and start tracing.

i don't remember for sure, but i wanna say one wire is blue and one is blue with a white stripe, or maybe one is brown.
not black though...

Last edited by krautrock; 04/23/18 10:04 PM.
Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: krautrock] #2486999
04/23/18 10:39 PM
04/23/18 10:39 PM
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
S
Sammy Offline OP
top fuel
Sammy  Offline OP
top fuel
S

Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Originally Posted By krautrock
wiring schematic for your model should show you where the wires are, they go to the bulkhead and then come through and run to the ballast resistor. my cars wiring was terrible to i just wired the two in series at the bulkhead and ran that to my msd box.

the first thing i would do is figure out which terminals in the bulkhead are ign1 and ign2, and test them with a dmm on the engine side of the firewall...in the run and start positions. if you don't get the voltage at that point, you need to go under the dash and start tracing.

i don't remember for sure, but i wanna say one wire is blue and one is blue with a white stripe, or maybe one is brown.
not black though...



At this point I just want to get the car started so I would have no problem bypassing the bulkhead.
Can you tell me where the wires go from the key switch? I think the 2 to 1 wire is my problem now. Do any go to the engine bay starter relay?

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2487082
04/24/18 01:16 AM
04/24/18 01:16 AM
Joined: Jan 2003
Posts: 123
C
CDoering Offline
member
CDoering  Offline
member
C

Joined: Jan 2003
Posts: 123
Sounds like the main power wire might have a bad connection somewhere. The MSD 7530 series ignition will still power up off the keyed 12 volt source with the light showing and able to be computer programmed but will not fire the ignition if there is a power supply problem.

I ran into this problem a few years ago working on my car. I had unhooked everything to replace the battery and the positive wire to the MSD fell back behind the battery in the trunk, I had a few other wires going directly to the battery positive side so I didn't see it right away. It was throwing me for a loop as I could power up the MSD and program with the laptop but it wouldn't fire the ignition.

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2487163
04/24/18 10:07 AM
04/24/18 10:07 AM
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
S
Sammy Offline OP
top fuel
Sammy  Offline OP
top fuel
S

Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
It is definitely in my wiring from my key ignition. I just need to know where the wires from the key go.
I think I cut something somewhere but I'm really not a electrical friendly guy.

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: CDoering] #2487203
04/24/18 12:07 PM
04/24/18 12:07 PM
Joined: Jan 2003
Posts: 2,094
central texas
K
krautrock Offline
top fuel
krautrock  Offline
top fuel
K

Joined: Jan 2003
Posts: 2,094
central texas
Originally Posted By CDoering
Sounds like the main power wire might have a bad connection somewhere. The MSD 7530 series ignition will still power up off the keyed 12 volt source with the light showing and able to be computer programmed but will not fire the ignition if there is a power supply problem.

I ran into this problem a few years ago working on my car. I had unhooked everything to replace the battery and the positive wire to the MSD fell back behind the battery in the trunk, I had a few other wires going directly to the battery positive side so I didn't see it right away. It was throwing me for a loop as I could power up the MSD and program with the laptop but it wouldn't fire the ignition.



try looking at these wiring schematics for your model.
http://www.mymopar.com/index.php?pid=27

one is the interior side, the other is the engine side. I don't know what kind of car you have, I looked one or two and it looks like dark blue and brown wires go from the ign switch to the firewall, through the bulkhead and to the ballast resistor (just labeled as resistor and it's located close to the coil).

first step, Find the bark blue and brown wires that went to the ballast resistor. make sure one has 11-12v with key in run, the other has 11-12v with the key in start position.
if they do, just wire both of the wires to the MSD 12v turn on lead, you will have 12v while starting and while in run...

Re: Switched from a MSD Digital6plus to a MSD 7531 and now no .. [Re: Sammy] #2487235
04/24/18 01:06 PM
04/24/18 01:06 PM
Joined: Feb 2014
Posts: 1,695
central il.
S
second 70 Offline
top fuel
second 70  Offline
top fuel
S

Joined: Feb 2014
Posts: 1,695
central il.
Sammy I had a problem with my msd where my car would crank over fine but just wouldn't fire. I assumed it was flooded and put a charger on it and let it sit for an hour and came back and with the charger still connected it started right up. Happened a few times turned out the battery was bad even thou it read over 12 volts and cranked the engine easily just didn't have enough voltage to fire the msd. New battery problem gone.

Good luck Mike







Powered by UBB.threads™ PHP Forum Software 7.7.1