Very strange starter / blower motor issue (with a side of windows and sunroof issues)

[1987E30]

Hi, I am new to posting on this forum but have been "lurking" for a few months, and am new to the E30 world (but not to cars).

My 1987 325iS was very much an "almost junkyard" car, as a reference, but it did start and run when I purchased it.

Currently, turning the key to run or start does nothing, but it does power the overhead diagnostic display.

Jumping the starter with a wire from the battery terminal (on the solenoid) to the terminal from the ignition switch results in the blower motor coming on, but only when the selector is in high. Note that for this test, the key is not in the ignition at all.

Checking voltage, I have 12+ Volts at the battery terminal to the starter, but 0.2 Volts (very constant) at the ignition switch. There is 0 Volts when the key is in any position except start (which is expected), but I expected 8-12 Volts in start.

Jumping pins 11 and 14 in the diagnostic connector have the same effect as jumping the starter terminals - blower motor comes on, but only at highest speed selected. For both tests, the relays (K5 and K7) click when I make the connection, and click again when I release it.

Not sure if I have a bad K5 or K7 relay, or a bad Start Relay (it is an Automatic, so there is a start relay), bad starter, bad ignition switch (although i seem to be getting responses to run and start in voltage and light tests).

Also it may be worth noting, the sunroof and all power windows and power locks do not work either. No fuses are blown (but the 25 Amp window/sunroof circuit breaker may be blown). Either way, those problems existed before the start problems appeared, so I don't think they are related.

I don't think my blower resistors are to blame for the blower motor only working at high speed, because I do not even have the key in the ignition for that test, I am just jumping the two terminals on the starter with a push-button test lead. I must be applying voltage to S232 splice when I jump the wires, but I'm not sure how.

Kind of a lengthy first email, but any help is appreciated. Thanks!

[1987E30]

As an addition, I have access to the Bentley manual, as well as the ETM, but am having trouble diagnosing this one.

[jlevie]

That sounds like a bad ignition switch or a wiring fault.

[1987E30]

Thanks for the quick reply. I'm not sure how a wiring fault could have happened - the car was running just fine (relatively speaking - a little rough) and all of a sudden this problem appeared. The battery is also brand new and should be able to turn the starter over. I haven't tried bench-testing the starter because I hear removing it is a pain, and I am only reading 0.2 Volts from the ignition switch at the starter.

If the ignition switch functions in Run (diagnostic lights come on), and start (voltage at switch goes from 0 Volts in Run to 0.2 Volts at start), would that mean it is switching correctly?

Could this be attributed to a relay that is stuck open or closed?

Thanks.

[1987E30]

I feel like the blower motor turning on but only in high speed when the ignition switch is jumped with the battery terminal is meaningful.

Why is that circuit getting power when jumping the starter? (with no key in the ignition at all, but battery connected)

[jlevie]

Voltage at the starter solenoid should be battery voltage when the key is turned to start. The blower running when you apply power to the starter solenoid control lug is just not right. The way I read the ETM with the ignition switch off there should be no connection from the starter solenoid control lead to the rest of electrical system.

When you do apply power to the solenoid control does the engine crank? If it doesn't something is wrong with the starter.

[Cephas]

I think you have a serious ground issue. Have you verified all grounds?

[1987E30]

Thanks for the continued help! The weird part is that looking at the ETM, S232 is the splice right before the blower motor, and bypasses the blower resistors, connecting to the high-speed setting on the blower control. S232 is also located on the start page of the ETM, (page 1240-0) right before the ignition switch.

It looks like there could be a combination of stuck relays that could inadvertantly complete a circuit when combined with jumping the power between the two solenoid terminals, and give power to S232, in turn supplying power to the blower motor?

The car used to behave normally and then the starter just went out - I can't imagine a wiring fault occured.

Also interesting to note: When the starting system failed, it failed mid-start. Meaning I was turning the key, the starter was in the process of turning the engine over, then just---stopped trying.

I have not tried checking voltage at the ignition switch terminal of the solenoid while trying to jump it, to make sure I am applying 12 V correclty to the starter. All I know is that as-is, the ignition switch terminal only sees 0.2 Volts.

When testing a starter inside the car, do I need to disconnect all the terminals and then give it 12V from the battery with jumper cables and then attach a lead from that terminal to the ignition switch terminal?

I get no crank, no sounds at all when turning the key to start.

[1987E30]

If I understand correctly, the starter is a ground for quite a few things, correct? Maybe that is the problem? The starter looks very very old and corroded.

[1987E30]

So i'm a mechanical head guy getting my feet wet in the electrical troubleshooting world - how many grounds are there? Are we talking about 10's, or 100's? Battery terminal ground is in great condition, but something tells me there are many more.

[jlevie]

S232 is on the battery side of the car's wiring and is hot all the time. You can see that that circuit feeds the ignition switch on 1240-0. If you look at 6413-0 you will see that power to the blower is only via relay K7

[1987E30]

Is the splice on the bottom of 6413-0 a typo? It lists S232, just before the blower motor. That part of the ETM is confusing me because I don't think it makes sense either (or am reading it incorrectly)

[1987E30]

May have had an electrical epiphany, or grasping at straws?

Looking at unloader relays, can they be energized from either end? Basically, voltage comes at pin 86 (from fuse 10 for k7, when in run or start), and goes through the coil. If voltage comes through pin 85 as well (from starter when starting), then relay is de-energized. Can voltage be applied to pin 85 (when jumping terminals on starter), but not on 86 (no key in ignition), and energize the relay? (from the wrong end)

Normally, k7 wants voltage at 86, and not 85, to energize relay. Will voltage at 85 and not 86 have the same effect?

That would explain why the blower motor comes on when jumping terminals on solenoid and no key in ignition.

Thoughts?

This doesn't fix my problem completely (no start), but may help me diagnose why I don't even have 12v at ignition terminal on solenoid. Once I have 12v, I'll look into the starter itself.

[jlevie]

On an 87 325is, power is supplied to the unloader relay coils by the the Hot in Start and Run circuit from the ignition switch, like all E30's. The starter on an 87 does't have an unloader switch in the solenoid (and the engine harness doesn't have that wire). The other side of the unloader relay coils is simply grounded.

At the risk of being redundant, the blower motor running when power is applied to the starter solenoid control terminal means something is wrong elsewhere in the car's electrical system. The first task is to find out what that is. The second task is to find out why system voltage isn't present at the starter solenoid when the key is tuned to start. The first and second tasks may have a common cause.

[1987E30]

So everything is wired correctly. Fuse 10 only gets 1.5v, and fuse 16, 17, 19, 20 see 12v when terminals are jumped. K5 and k7 are energizing from the back end, and the blower motor (fuse 20) is being powered. If fuse 10 Saw 12v, the relay would be deenergized.

I'm not concerned with the blower motor as it is explained by fuse 20 getting power. I don't understand how fuse 10 would not see 10 volts?

Once i get fuse 10 understood, I can check start relay, range switch, and ignition switch. Ignition switch seems ok because certain interior lights (overhead diagnostics) come on in "run".

If it helps, fuse 3 saw 0.05v, and 12 saw 0.4v when terminals were jumped. No key in ignition for any of these tests.

Other fuses to see power (12v) were 21-28, but they all run lights that will work with no key, so that was normal.