1990 240DL 161k miles

Beginning about a month ago I began experiencing an occassional problem when trying to start the vehicle. While almost all the time the starter will engage when I turn the ignition key to the start position, sometimes the starter does not engage. When that happens the idiot lights on the cluster remain lit and I do not hear any noises from the vehicle (e.g. clicks or buzzes). Another clue I have is that if the headlights are on, they will go off when the ignition key is turned to the start position - this happens both when the starter engages or does not engage. With that being said about the headlights, I would guess that the ignition switch itself is OK. Is that a safe assumption? I replaced the starter in January 2012.

Suggestions?

 

Assuming you have an automatic transmission, when the starter fails to engage, try wiggling the shifter. Most of these vehicles by now have worn out shifter linkage bushings between the shifter and the transmission. This makes gear selection sloppy which can cause the neutral safety switch to think the car is in gear. If the car starts when you wiggle the shifter - and you have sloppy gear selection - then you probably need new shift linkage bushings. They are cheap at FCP and aren't too difficult to replace.

 

Your starter is failing. The fact that the lights DIM when key is turned means that the starter is getting the current but not responding is it should... Good clue!

 

I don't see it mentioned anywhere in his post about the idiot lights dimming. In fact he says they stay lit. The headlights go off but that is normal operation when you turn the key to the III position.

I agree with his original assessment that the ignition switch seems to be working properly.

 

Yes, it's an automatic and I had "wiggled" the shifter when I have had the occassion of the starter not engaging. That did not seem to have a correlation to when the starter eventually engaged, but I think this is a good place to make sure things are working as they should.

The bushings on my shifter linkage are long gone. I assume they were plastic that eventually self-destructed. I have also lost one on the funky clips that secures the shifter shaft to the transmission linkage. I've got that held in place by wrapping a piece of wire around the head of the stud from the shifter shaft. Is the shifter override a switch or is it just a simple contact?

A while ago I did buy some replacement bushings but I did not grasp on how to get that solid, hard, plastic bushing thru the smaller hole in the linkage. What's the secret to installing the bushing?

 

Don't worry about your linkage bushings disintegrating, they have nothing to do with the Neutral Safety Switch, sloppy as they make shifting feels...

The reason the headlights dim, (normal operation) is because huge amount of current is being drawn by the starter indicating that the current is in fact getting to it. If the ligts don't dim, it would mean that the starter gets no juice, pointing to another problem.

 

Thanks for your input but I'm not sure about what you're saying about the headlights - seems like you're saying that it's normal for the headlights to be on when the starter is engaged. I've had other cars where that might be true but not with this Volvo. My observation is that normal operation cuts power to the headlight when the ignition key is turned to the start position.

Anyway, sounds like I oughta locate the neutral safety switch to see is I can ascertain if that is the source of my problem.

 

indeed, on a 1990 Volvo 240, there's a headlight relay, greenbook seems to show it under the driver side dashboard, thats ONLY engaged when the ignition is in position II, not in I or start, this provides the headlight power.

wiring goes like this...

battery + to positive terminal to ignition switch pin 30.
ignition switch pin 15I (powered only in position II) has blue-red wire to headlight switch pin 15I. headlight switch pin 56 has a blue-white wire to headlight relay pin 86 (coil) and pin 85 goes to ground.

meanwhile... positive terminal red wire to input side of fuse 6. fuses 6-7-8-9-10 are bridged, and the input side of fuse 7 has a green-red wire to headlight relay pin 30 (common side of relay switch). relay pin 87 has a yellow wire to pin 56 on the 'step relay' up behind the headlights (the step relay switches between high beams and low beams).

I'm leaving out the high/low control circuit as its just complicated

so.... when you turn the key to 'START', that yellow wire should be cold, and the headlights should go completely out.



now... if the neutral/park safety switch is malfunctioning, the motor won't crank over at all. if that's whats happening, holding the key to start and wiggling the shift lever may cause it to crank.