• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Help With Ignition Problem

  • Thread starter Thread starter 93CalypsoConvert
  • Start date Start date Nov 26, 2020
  • Tags Tags
    electical ignition wiring

93CalypsoConvert

Active Member
Nov 26, 2020
275
91
38
Virginia
Nov 26, 2020
#1
  • Nov 26, 2020
  • #1
Hello,

I'd like to begin with saying this is my first post, so let me know if I'm doing something wrong here. The other day I bought a 1993 Calypso Green convertible and its got some problems I can't quite put my finger on yet. The car was originally a 2.3 5 speed, but the previous owner swapped in a carbureted 5.0. One of the problems is he ditched almost all of the electronics, making the wiring a total nightmare (harnesses and connectors EVERYWHERE). The problem I am having now is no spark while cranking. The second I let off the key, it gets spark and starts. How do I fix this? Where do I need to give to coil power from to get spark while cranking? Also I am trying to reconnect the original tachometer. Do I connect the gauge cluster wire to the negative coil?
Thanks.
 

HemiRick

I'd be looking at jacking under the house
Jun 28, 2020
723
272
73
Memphis TN
Nov 26, 2020
#2
  • Nov 26, 2020
  • #2
This sounds like an ignition switch issue, they are notorious for going bad.
 
Reactions: 90sickfox

90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
6,945
5,816
213
Nov 27, 2020
#3
  • Nov 27, 2020
  • #3
Hello, welcome to the forum. There are lots of guys here that can help with this. Pictures are always a huge plus with stuff like this.

You'll need a test light to find the wire on the ignition switch that has power when in the cranking position and in run....but off when switched off. The coil should be connected to that wire. I could be wrong but I think the dark green and yellow stripe wire ( could be tan / yellow ) is coil ground for the tach. Red and light green stripe should be power from ignition switch to coil. ( can be verified with test light ). The ground could be connected straight to a good ground. The computer used the tach ground to control timing. Your car should have a vacuum advance distributor or one of the HEI style that has the coil on top of the cap. These styles mechanically control timing so a straight ground wire can be used for coil.

The 4 cylinder cluster tach won't work right with a v8. It'll read wrong because its set up for a 4 cylinder. Your year ( 93 ) used a signal from the computer to run the tach. The easiest way is to buy a V8 tach and wire the coil negative to it.

The correct way to fix your issue would be to get a complete engine harness for a 93 v8....that would also mean getting a proper computer and going efi. ( bunches of sensors and such ). I wouldn't be mad if you didn't go that route. A carbureted car can be cool if its done clean and with the correct parts.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
27,826
10,506
203
polk county florida
Nov 27, 2020
#4
  • Nov 27, 2020
  • #4
Carb swaps used to give me a stomach ache but I've noticed we are getting more requests for help in this area and we are here to help.
Most times it's a 4 cyl to V8 swap that get the carb treatment like yours did, in order to help there is a need for some info:
Is the computer still present along with the 4 cyl instruments
Did it run when you acquired it
Do you want to keep the carb or update to efi
Also what is your level of mechanical ability
 
H

Haste347

Member
Oct 6, 2020
16
3
13
Houston
Nov 27, 2020
#5
  • Nov 27, 2020
  • #5
Make sure the coil/ignition is not connected to the starter solenoid. Letting off the start key, then immediately getting power to the item needed for spark sounds highly suspect of this being the issue.
 

93CalypsoConvert

Active Member
Nov 26, 2020
275
91
38
Virginia
Dec 3, 2020
#6
  • Dec 3, 2020
  • #6
General karthief said:
Carb swaps used to give me a stomach ache but I've noticed we are getting more requests for help in this area and we are here to help.
Most times it's a 4 cyl to V8 swap that get the carb treatment like yours did, in order to help there is a need for some info:
Is the computer still present along with the 4 cyl instruments
Did it run when you acquired it
Do you want to keep the carb or update to efi
Also what is your level of mechanical ability
Click to expand...
Yes, the computer is still present. All of the instrument panel works.
It did run when I bought it.
I would like to keep the carb setup.
High mechanical ability.
 

93CalypsoConvert

Active Member
Nov 26, 2020
275
91
38
Virginia
Dec 3, 2020
#7
  • Dec 3, 2020
  • #7
90sickfox said:
Hello, welcome to the forum. There are lots of guys here that can help with this. Pictures are always a huge plus with stuff like this.

You'll need a test light to find the wire on the ignition switch that has power when in the cranking position and in run....but off when switched off. The coil should be connected to that wire. I could be wrong but I think the dark green and yellow stripe wire ( could be tan / yellow ) is coil ground for the tach. Red and light green stripe should be power from ignition switch to coil. ( can be verified with test light ). The ground could be connected straight to a good ground. The computer used the tach ground to control timing. Your car should have a vacuum advance distributor or one of the HEI style that has the coil on top of the cap. These styles mechanically control timing so a straight ground wire can be used for coil.

The 4 cylinder cluster tach won't work right with a v8. It'll read wrong because its set up for a 4 cylinder. Your year ( 93 ) used a signal from the computer to run the tach. The easiest way is to buy a V8 tach and wire the coil negative to it.

The correct way to fix your issue would be to get a complete engine harness for a 93 v8....that would also mean getting a proper computer and going efi. ( bunches of sensors and such ). I wouldn't be mad if you didn't go that route. A carbureted car can be cool if its done clean and with the correct parts.
Click to expand...
Ok, thanks for the info. I found the dark green wire you were talking about. Only problem is when I turn the key to crank, the wire either turns off or is grounding somewhere. Still trying to figure out whats going on here.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
27,826
10,506
203
polk county florida
Dec 3, 2020
#8
  • Dec 3, 2020
  • #8
Nothing really wrong with a tastful carb setup.
Keep us posted on what you find.
I would start by checking the ignition switch under the dash.
 

90sickfox

Wasn't a pretty sight...and I've got big hands
SN Certified Technician
Mar 2, 2015
6,945
5,816
213
Dec 3, 2020
#9
  • Dec 3, 2020
  • #9
Can you post a picture of what you're dealing with ?
 

93CalypsoConvert

Active Member
Nov 26, 2020
275
91
38
Virginia
Dec 3, 2020
#10
  • Dec 3, 2020
  • #10
Found the problem! So the +12 wire that was supposed to run off the ignition switch was actually being run off a wire from the fuse box. It was running off of the ac and blower motor fuse, which deactivates while cranking. I have now routed it correctly and it starts normal. Thanks for the insight.
 
Reactions: Monkeybutt2000, General karthief and Cheapskate207
You must log in or register to reply here.

Similar threads

8
Electrical Crank-no start ... no spark ... no injector pulse, was it something I did? (redux)
  • 85gtCOBRA
  • Oct 28, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
485
Fox 5.0 Mustang Tech Oct 29, 2025
85gtCOBRA
8
J
5.0 ignition wiring help
  • Jetscat7
  • Nov 25, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
3
Views
169
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Nov 25, 2025
Noobz347
Engine Duraspark ignition box
  • limp
  • Oct 26, 2024
  • Fox 5.0 Mustang Tech
Replies
12
Views
599
Fox 5.0 Mustang Tech Jul 21, 2025
manicmechanic007
8
Did I fry something messing with my ignition?
  • 85gtCOBRA
  • Oct 18, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
30
Views
952
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Nov 15, 2025
85gtCOBRA
8
Drivetrain 83’ Glx convertible C5 Trans help!
  • JacksonJared2113
  • Dec 25, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
319
Fox 5.0 Mustang Tech Dec 26, 2025
JacksonJared2113
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?