how many ohms should an ignition module be?

It's kinda hard to tell much from ohm readings, you really need it to be in an operating circuit to test it.

Just managed to get our hands on a new one to test and the readings are significantly higher - in the 8-9 range. Perhaps the stalling problem is the ignition module and its not serving enough power.

I don't think you fully understand what you're measuring. The readings could be different simply due to a different design of a circuit which performs the same thing. Try the new one in the car and see how it behaves, that's the only way to test it.

The repair manual I have (Bentley) gives readings, but only when the vehicle is running.

Sort of a Catch-22.

No difference unfortunately, the car is still refusing to start at all now. Thankfully we only borrowed it from someone :-)

Testing in situ gives the following recommended readings. (a) Terminal 4 to ground and/or ignition coil terminal 15 should read 12Volts. (b) Terminal 5 to ground with starter motor operating should show a pulsating reading between 0 and 2 Volts. (c) Terminal 1 to coil terminal 15 should read 0.6 to

All the best, Peter.

What car is this and what condition is the wiring harness in? If it's earlier than an '89 or so and the engine harness is original then that's likely your problem.

Do check the hall sensor though.

We think its possibly the fuel pump relay (its a 1993 volvo 240e). Symptoms (car stalling on slowdown to junctions from a warm engine start) point to fuel pump relay although the relay looks in very good condition. Going to see if we can borrow one to test the car.

Is the fuel pump running? You should be able to hear it under the car while cranking the engine.

The outside of the relay can look fine and it can still be bad. You have to pop the cover off and inspect the soldering on the circuit board.

We had a look at it last night, popped open the cover and it looked brand new inside, no corrosion or anything. It was suggested that when the car cut out, to place a wire between fuses 4 and 6 to see if the car would start. If the car started it was probably the relay. It did start, but unfortunately we do not know if it would have started anyway.

The failures show up as hairline cracks in the solder, running around the leads for the relay connections. When I was young I could see them in any light; now I have to take it into the sunlight and take my glasses off :-(

Mike

I was looking for corrosion :-( If we do find hairline cracks, is it possible to just resolder it and be done with it? Am finding it extremely difficult to find a replacement. One company says they can get one but it will be a 6 week delivery. We need a fix now as the car is getting steadily worse.

Have you asked IPD if they have one?

All the best, Peter.

Yes, resoldering is the recommended alternative to replacement.

Gary

Yes, it takes about 5 minutes. Just heat up the joints with a soldering iron and flow in a bit of fresh rosin core solder, then let it cool. Any TV repair shop can do it for you if you lack the tools to do it yourself.

Hi Peter thanks for the link, I actually found one finally later yesterday. Going to pick it up today.

Ohm Sweet Ohm