Technical No Crank Condition

[CSpald]

Hi, I was wondering if anyone could help with this. I have been trying to fix this for a few weeks now. While checking fuse for blower motor, a mechanic broke the starter relay, which got replaced, and still doesnt crank, I've replaced the Battery, Starter Motor fuse which was blown but hasn't blown since, I'm going to add an additional earth strap in case I was getting bad ground, but don't see anything wrong with current ground connections, mechanics told me the starter motor is fine, Ignition barrel worked fine before relay was broken, immobiliser light goes off after a couple seconds so I dont think its that. Any ideas?

 

[bugsymike]

Hi, I was wondering if anyone could help with this. I have been trying to fix this for a few weeks now. While checking fuse for blower motor, a mechanic broke the starter relay, which got replaced, and still doesnt crank, I've replaced the Battery, Starter Motor fuse which was blown but hasn't blown since, I'm going to add an additional earth strap in case I was getting bad ground, but don't see anything wrong with current ground connections, mechanics told me the starter motor is fine, Ignition barrel worked fine before relay was broken, immobiliser light goes off after a couple seconds so I dont think its that. Any ideas?

If all the fuses and relays are working, I would then check I was getting a starter signal from the ignition switch into the wiring loom, then from the other end I would check if there was a feed to to the starter solenoid and also double check if I could activate the starter solenoid and get the starter to work.
It is possible when shorted it damaged the wire giving the signal to the ECU, hopefully not the ECU!

 

[Mike1alike]

Since the problem started when the starter relay was broken/replaced, it might be worth checking the control circuit around that relay rather than the starter motor itself.
A few things to check:
• Make sure the replacement relay is the correct type and seated properly.
• Check that the relay socket terminals weren’t damaged or pushed back when the original relay broke.
• With the key turned to START, see if 12 V appears on the relay control pin from the ignition switch.
• Also check if the relay clicks when turning the key.
If the relay is not being triggered, the issue could be in the ignition switch circuit, wiring, or the relay socket, rather than the starter motor itself.

 

[Mike1alike]

a mechanic broke the starter relay, which got replaced

The relay or the mechanic?!
Was the relay replaced with a new correct relay, or just another used one?

 

[puntodad19]

Grand Punto....

Research on elearn...

How system works, wiring diagram and location drawing...even s test procedure...

Modern cars are computers on wheels with miles more wiring than old school easy fix ( relatively ) systems.

Be carefull what you "probe around with" as the computer bits will not like sourcing much current and will sink much more.

A digital multimeter is relatively "safe", as is a scope.

Get the correct exact info from elearn etc....before you push too much current up a computers bum.

Having said that, relays usually switch 12volt ( although the relays "triggering signal" may be less and low current. ). Energising the starter motor solenoid via 12v is usually ok.

See elearn to he absolutely sure.

Computer stuff is easy to damage.

 

[GrandePunto PL]

Yes. Any electrical problem = you open the schematic diagram.

Power: https://aftersales.fiat.com/elearnsections/main.aspx?nodeID=199001190&languageID=2&markID=1&modelID=199000000&valID=199000000&prodID=199000000&modelName=Fiat - 199 - Grande Punto&langDesc=English&sectionName=Impianto Elettrico&validityName=1.2 8v

Starting & recharging: https://aftersales.fiat.com/elearnsections/main.aspx?nodeID=199001400&languageID=2&markID=1&modelID=199000000&valID=199000000&prodID=199000000&modelName=Fiat - 199 - Grande Punto&langDesc=English&sectionName=Impianto Elettrico&validityName=1.2 8v

Basic faults are not "mystery" whatsoever (it should take few hours max., not weeks to fix).

 

[puntodad19]

Nice one GP.

 

[CSpald]

Yes. Any electrical problem = you open the schematic diagram.

Power: https://aftersales.fiat.com/elearnsections/main.aspx?nodeID=199001190&languageID=2&markID=1&modelID=199000000&valID=199000000&prodID=199000000&modelName=Fiat - 199 - Grande Punto&langDesc=English&sectionName=Impianto Elettrico&validityName=1.2 8v

Starting & recharging: https://aftersales.fiat.com/elearnsections/main.aspx?nodeID=199001400&languageID=2&markID=1&modelID=199000000&valID=199000000&prodID=199000000&modelName=Fiat - 199 - Grande Punto&langDesc=English&sectionName=Impianto Elettrico&validityName=1.2 8v

Basic faults are not "mystery" whatsoever (it should take few hours max., not weeks to fix).

Thanks for this, seems i'm way out of my league here I have no idea where to even start lol

 

[CSpald]

The relay or the mechanic?!
Was the relay replaced with a new correct relay, or just another used one?

Both lol, Yea i matched part number and whatnot

 

[Mike1alike]

And can you hear the relay clicking when you turn ignition on?
Was relay correctly connected, the wire firmly attached where it should?

 

[Mike1alike]

On a Fiat / most models (and most cars in general), the starter relay acts as a switch between the battery and the starter motor. The wiring works roughly like this:
Battery → starter relay (pin 30) – main +12 V supply
Relay output → starter motor (pin 87) – when relay closes, full battery voltage goes to the starter
Relay coil (pins 85 & 86) – energizes the relay when the ignition switch sends +12 V
Pin 85 usually goes to ignition switch / ECU
Pin 86 usually goes to ground (or the other way around depending on car).
If the wire between the relay output and starter motor is loose, disconnected, corroded, or swapped, the starter won’t crank, even if the relay itself clicks.

 

[Mike1alike]

Hi, I was wondering if anyone could help with this. I have been trying to fix this for a few weeks now. While checking fuse for blower motor, a mechanic broke the starter relay, which got replaced, and still doesnt crank

Quick question: when you say 'starter relay' you mean the actual relay from the fuse box or the starter solenoid which is often being referred to as 'relay'?

 

[CSpald]

Quick question: when you say 'starter relay' you mean the actual relay from the fuse box or the starter solenoid which is often being referred to as 'relay'?

starter relay in the fuse box yea. I'm also going to try replacing the engine management relay as when I bump/push start it, the engine light comes on and the car misfires slightly, was told that a bad engine management relay could cause that alongside no crank condition

 

[CSpald]

If the wire between the relay output and starter motor is loose, disconnected, corroded, or swapped, the starter won’t crank, even if the relay itself clicks.

I will also check this, thank you. The relay itself clicks yea when the key is turned, so i'd imagine you are correct