93 850 microswitch fixed but now car won't start

LarryDVA · Post by **LarryDVA** » 07 Jul 2014, 18:42

So what did I do? My 850 had the classic switch interlock issue so I got a new microswitch and replaced per instructions on Volvospeed. What a PITA to get to! So I put it all back together and now the shifter will move from park when I press on the brake but...now the ignition is not functioning. Its too hot and I am too tired to disassemble again tonight. Any idea what may have caused this issue? I did slide the grey ignition physical cable to the side per the Volvospeed instructions but replaced it back like it was. Is this an adjustment thing or electrical genie? Any ideas before I tear it back apart tomorrow evening?

Post by **cn90** » 07 Jul 2014, 19:37

Did you disconnect the battery during the procedure?

This is a lengthy process (replacing the switch), and you might have drained the battery.

Did you solder the switch in properly?

More photos here:

https://www.matthewsvolvosite.com/forums ... 5&p=267629

LarryDVA · Post by **LarryDVA** » 07 Jul 2014, 20:05

I didn't trust the crimp connector that came fitted on the Volvo replacement switch and the leads were very short. So I soldered on some longer leads and used heat shrink tubing to insulate the connections. The shifter now works without using the over ride button so I am confident the soldering was ok.

I did not disconnect the battery. I took me a couple of hours but I cannot imagine the battery would run down in that much time. The headlights come on. Could it be related to the grey cable connection to the ignition switch? Are the grey and black multi-pin wiring connectors related to start functions?

I'm thinking tomorrow I'll pull the console again and make sure the multi-pin connectors are seated properly and wiggle the grey physical cable to see if that does anything. Not sure where else to turn?

Post by **abscate** » 08 Jul 2014, 03:14

This switch is all about inhibiting starting so I am pretty confident it's the cause of your no start condition. I don't have this one on my sticks, though, except on the clutch pedal

LarryDVA · Post by **LarryDVA** » 08 Jul 2014, 06:56

Curious, the micro switch simply makes the ground connection for the servo that locks the shifter. I do not see that there is any electrical connection of the micro switch to the ignition switch. Is this a correct observation?

I am thinkin that the only connection to the ignition switch is the physical connection provided by the grey cable. Is this correct?

There are two multi-pin connections that must be disconnected to remove the console. A grey one and a black one. I am not sure if they are related to the ignition fault but I will recheck those connections tonight to verify that they are fully seated.

BTW, I put the battery minder plus charger on this morning so as to make sue the battery is fully charged when I rengage this project tonight. I wasn't expecting this to be a complex job, but I was wrong.

Post by **BEJinFbk** » 08 Jul 2014, 08:21

abscate wrote:This switch is all about inhibiting starting so I am pretty confident it's the cause of your no start condition. I don't have this one on my sticks, though, except on the clutch pedal

?
The shiftlock microswitch isn't connected to engine starting at all.
It's just a safety device for ensuring that you have your foot on the
brake when you shift the car out of park.

PNP related, perhaps?

Let me back up a minute...
What exactly do you mean by the ignition is not functioning?
Does the key physically turn?

Post by **cn90** » 08 Jul 2014, 08:23

A quick jump start will answer the question.
If the car starts with a jump, your battery was drained.

LarryDVA · Post by **LarryDVA** » 08 Jul 2014, 08:45

The key will turn to the start position. When it's turned to the start position, the starter does not engage and the dash lights flash on and off erratically.

What are you referring to with "PNP"?

I thought of jump starting but figured I would simply put the charger on the battery while I am at work today and make sure it's fully charged by the time I get back to it after work tonight.

Thanks in advance for the input.

Post by **BEJinFbk** » 08 Jul 2014, 09:41

The PNP is the set of contacts on the transmission that
tell the TCU, starter relay and backup lights what gear
the car is in. Did you goof around with the big cable on
the shifter that runs through the firewall? You may be
out of adjustment.

LarryDVA · Post by **LarryDVA** » 08 Jul 2014, 10:08

There is a steel cable enclosed in a sheath that is attached to the shifter. Is that the cable you are referring to? If so, yes, I moved it per the Volvospeed article to see the micro switch. On hindsight, there was no need to move it as the micro switch is accessed from the opposite (drivers) side of the shifter. I didn' t disconnect the cable, I just slid it out of the way and put it back when I was done. Is there an instruction on it's adjustment? I can't imagine it has changed position much if any.

The Volvospeed article refers to the "grey cable as the mechanical lock that goes to your ignition switch". So I am confused, is this the same cable you are referring to that goes thru the firewall?