I’m a bit stuck
My 1988 volvo 740 won’t crank over

Battery and connections ok
Power fed to green starter motor trigger wire does crank starter so starter is ok
Tested key switch by exchanging it with a spare
Tested park neutral safety switch -ok

When key is turned to crank ,
headlights dim and I hear a slight click from relay tray swapped relay marked J

Tried following Haines manual, for 87 and newer
It indicates power fed from key pin 50 through park switch to starter

I checked each wire at starter switch there is not one tgat is hot when key is turned to crank position tgat us not hot in other key positions

Found Volvo schematic , it seems to indicate much differently
Oh jetronic B230F starts on page 8 ( I’ll post link after )

It shows a test plug and wiring ( page 8)
9 is the starter motor wire at starter is BL- GN

To “p” - connector , electrical distribution unit seems to show a small jumper ,

To “B” - Connector left A post - pin 24

Through pink wire

To “A” - connector right A post - pin 15

To ECU pin 30
—————————————————-

So the Haines schematic seems completely wrong
and the starter is not fed from key but fed from the ECU

The difference in the two schematics totally confused my efforts to understand the path of the starters trigger wire

I’d like to identify this test port for the starter , I thought it may exist to aid in cranking to check compression etc by a mechanic or to verify the 12v to starter upon cranking

Am I on the right path ?

I can imagine a lot of people got caught with no crank issues due to the Haines manual’s 740 1987 and later schematic indicating the key as being the source of power to crank the starter

I am assuming the Volvo schematic that
I have which dates about a year after my car to be correct

Thanks for any info you guys can offer


Phil