EDIT : corrected relay reference below. Last week about this same time my 328 stalled backing into the garage. Below is the thread I posted, and believed everything was solved with the main fuel pump relay. https://www.ferrarichat.com/forum/threads/328-wont-start-after-stalling.663050/ So this week I've been driving with the old relay from the horn in the fuel pump slot but ordered a couple replacement relays and keep one of each type here at the house, just in case. They came in over the week. Last night I put the old metal casing relay back in the horn spot and the fresh new one in position for the fuel pump. Drove a little last night and about 40 miles today. Backing into the garage, almost the exact same place and position... it dies again and won't restart. OK so we'll discuss the chances of that happening twice at the same ~ time of day, exactly 1 week later, same place, and same circumstances some other time... but how can you not note that. So here is what I've found. Fuel pump again not running. Swapped Horn relay back to fuel pump... not it Grabbed the other model new relay I purchased and swapped the lower fuel pump relay as well (lower left corner)... not it. Pulled the safety switch... not it Ahh wait.. fuse... check the fuse... Its blown. OK so I'm on my way to get another fuse, but here is the real questions: I also realized they sent me the wrong relay. I ordered the Bosch 0332 019 151. What they sent was a Bosch 0 986 AH0 25. Some dummy.. who needs not be reminded of it.. didn't check the relay that came in and verify it was correct. I found the tech diagrams for the correct relay and the one they sent, attached to this message. I see differences: The Life Durability rating - Correct 250.000 - Shipped 100.000 Pins 85/86 are swapped - these are the control coil pins (not sure this would matter?) Correct relay has no resistor - Shipped relay says it has a resistor. So.. Would this incorrect relay potentially have caused the fuse to blow? Would it potentially cause any other issues? If no to both of those questions..... being I have lost both a relay and a fuse on the fuel pump system.. is there another root cause I should be looking into. Leaving in a few minutes to go get the fuse and will set it back up with all original relay parts, new fuse and nothing installed for the horny. I'll report back if the car starts or not in 30-45 minutes. Image Unavailable, Please Login Image Unavailable, Please Login Thanks again to all who have and continue to help.
Have you tried opening up the old relay and resoldering its circuit board? I have done this several times, and some relays began working again and have continued working. If the new relay with the resistor reduces the voltage at the fuel pump, it may cause the fuel pump under load to draw more current possibly blowing the fuse. If the DC motor does not run fast enough, there is less 'back emf' which allows it to draw more current. There are some persons on this list with very good electrical backgrounds who might comment.
Fuse replaced, car started up fine. Currently have all original relays in position. Dealing with getting the correct relays, but the questions above still remain. Could the differences in the two relays have caused the fuse to blow after 40 miles of driving? Could anything else have been damaged? (doesn't appear to be) If the wrong relay is not an issue specifically what caused a relay to go and then a week later the fuse to blow? What else out there should I be troubleshooting. I looked back through the service records and not seeing a fuel pump replacement any time in the past 10 years or more. Fuel filters routine, but no pump.
Thanks for this and I see the logic in the potential current draw. I do not know where or how that resistor is positioned, how it affects current passing through or to what extent. This is clearly one of those situations where I know enough to understand the concept but also that know that I don't know enough. Hopefully someone else may chime in.
Even though that resistor box is checked in the table, the symbol doesn't show the resistor (which is connected between terminals 85 and 86). Having the resistor helps to reduce the arcing at the switch contacts in the whatever upstream thing that is supply the +12V and/or ground to terminals 85 and 86 to actuate the relay. Either that resistor box wrongly got checked in the table, or they mangled the symbol. Nothing indicates that that relay wouldn't work OK, nor that it should cause a problem (even if it does have a resistor between terminals 85 and 86). See this link (even though it's a slightly different type relay): https://www.12voltplanet.co.uk/mini-change-over-relay-12v-2030a-with-resistor.html for an example of how the symbol should be if it does have the resistor between terminals 85 and 86 (the additional small rectangular box symbol connected between terminals 85 and 86). If the relay symbol shown on the relay case itself does not have that additional rectangular box = I'd guess that it doesn't have that resistor inside and they just mucked up the table (and viceversa).
See this post for a link to an inexpensive "fuse buddy" device that will plug in where your fuel pump fuse goes to measure the current that fuel pump is actually drawing (if you are worried about that): https://www.ferrarichat.com/forum/posts/148669408/ 9A~11A would be "normal" IMO.
Thanks for this. I will buy/order one and check it out. I did go look for a frazzled connector, but didn't see the metal plate with two plugs like the photos you sent in the other thread. I did have a single larger 17 pin plug to the right of the fuse/relay panel, but not plate mounted plugs in your photo. I included photo of the spread under the passenger footrest. If I'm missing, where is the plate with two connections located? Is there anything else I should be running down other than checking the current draw off the fuel pump? Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
I'm not sure that all 328 are the same for those connectors in the passenger footwell (so maybe all don't have the metal mounting plate). I don't really follow your comment of "I included photo of the spread under the passenger footrest". However, a bad connection in that connector group in the passenger footwell behind the footrest panel can't cause the upstream fuse to blow or cook a relay (it can only cause the fuel pump to not run). I'm not sure that you are even there yet . If the new fuse blows again = then measuring the fuel pump current draw is probably justified. They cut it kind of close using a 15A fuse on a device that draws ~10A when it's working correctly. These fuses are really thermal devices that blow from too much heat from the current passing thru them, but, if you have a bit of a bad connection to the fuse terminals (even just a few tens of milliOhms) that bad connection also generates a lot of I^2*R heat which will cause the fuse to blow at a lower current than it's rated = make sure the female terminals on the fuse-relay PCB that connect to the male fuse terminals are clean and "tight".
I was referring to the photo of the fuse/relay panel and connectors under my dash.. and looking for the "frazzled plug" but I understand your response. My thought was that if the pump was pulling too much current this would have caused the burnt connection, not the other way around...... but the real question is.. What would cause a relay to blow one week and the fuse the week after? Both just old? (it actually didnt look like an old fuse). My brain is having a hard time just calling that coincidence and looking for some root cause.. I can carry a spare relay and fuse with me . just in case, but not wanting to find myself roadside the next time.
Hard to believe there is really a resistor in the relay. Makes no electrical sense to have a resistor in the main circuit though perhaps they might have used one for the relay coil activation circuitry...though can't think why. As stated, the only thing that can cause the relay and/or the fuse to blow is excessive current being pulled through the circuit. Several things could cause this, including an intermittent short in the wiring, faulty connections, etc. With the pump itself, worn bearings/bushings in the pump or something obstructing the flow of fuel from the pump output could also increase the load. That fuse-buddy thingie looks like a cool troubleshooting tool - I'll have to get one! You mentioned that the fuse blew when the car was in the same physical location as when the relay failed. Was the operating time from car start to fuse/relay failure close to the same in both cases?
Sometime fuse just up the ghost from repeated surges on turn on, like a light bulb the blow after being turned on a few hundred times. Depends on how high the current surge is to the fuse rating (it can exceed it).
Agree that those events seem somewhat unrelated, and, usually, if the fuel pump is drawing excessive current, the fuse would blow before the relay suffered damage. However, there's also a cumulative damage factor going on so maybe a relay already near death could get pushed over the edge first. I think you are left with either the fuel pump current is high or your fuse connection is/was poor/aged.
The circumstances are perhaps (in my mind anyway) the most puzzling part of this. Both times it was a Saturday afternoon after having driven around for a bit. This Saturday was 40-50 miles. Last Saturday I think was considerably less but I can't say for sure. Both times I was backing into the garage. I only have about 6-8" to spare on either side of the mirrors so I admittedly baby this a little bit. Add to that there is a 12" high 10 foot long ramp to get into the garage, its not the best of circumstances. There is a 90 degree turn to get in and out of the garage off the driveway. with the layout of things its just an easier process to back in, than back out. So backing in, tight clearances going uphill... I'm letting the clutch out, really trying to not give it too much gas and it shut off in that action both times... That's why I thought I had stalled the car. It felt like I had stalled the car, it just wouldn't re-start. Both times something blown out in the fuel pump system. The identical and very specific circumstances lead me away from an intermittent short in they system.. its too coincidental. The fuel pump itself is either on/off, correct (it's not variable)? There is no time the fuel system could ever try to "increase the fuel pressure" in a near stall? Or could a stall somehow cause fuel pressure to back up and the pump current draw to spike before it shuts off? I haven't found records of a new fuel pump being installed so if it's old, worn, perhaps drawing high anyway, would the engine suddenly stopping with power still on the pump cause the spike? Admittedly I'm above my pay grade on this, just looking for something logical for a cause.
I once dealt with an ignition coil that would cut out in hard left turns. It was fine in any other maneuver! Turned out to be something internal in the coil would short or ground in that maneuver. Coil bench tested as excellent! Wonder if that uphill maneuver does something similar? I know it sounds totally weird but can you replace the fuse, start the car, drive out to the street then immediately go back up the drive and see if it occurs? If it does it would definitely point to something in the fuel pump or associated wiring physically moving/shorting. Another weird one - Are the engine mounts OK? Not sure on one of these cars with that cross fitting on the top of the engine but broken engine mounts on a US car engine can cause the engine to twist/lift off its mount on one side. I've seen that cause electrical issues as well - pulling on a wire/loss of ground, etc. The test was to put car in a forward gear, apply brake on and add some throttle. Do the same in reverse. With a broken mount the engine would twist/lift up on one side very noticeably! I'm not aware of anything in the fuel pump system that, under normal operation, causes it to vary its delivery rate and, therefore, its current draw.
1. there is a hard right turn in the backing operation but both times the wheel was pretty much straight when it stopped. The hill is not enough of an incline itself to shift much. 2. I've been in and out of the garage more than a few times without issue, but I honestly can't recall it actually stalling other than the two times the issues occurred. 3. As to the motor mount test, I'm familiar with it in an automatic trans car, but not sure how you do it on an old 5 speed.
For a manual gearbox - In 1st gear, clutch in, engine running, brake pedal applied. Keep brake pedal depressed, slowly ease out clutch/add throttle until car starts trying to move forward/rearward. Do not let clutch out to full engagement or, of course, the engine will stall. You are now "slipping the clutch." You can vary the RPM/clutch slip as necessary. It only takes a few seconds to determine if there is/isn't a problem with the mounts.
Mine go a bit more "wobbly" when stuck in traffic on a hot day. Not sure if this is normal?, but in case yours are the same, best to do this test when the engine has been pumping out some heat with the car at a standstill.
Latest update, behavior is still not fully explained or under control: The fuse buddy showed up and the fuel pump runs 9.5 to 10 amps.. so that seems fine. Right now I'm running on the old relays, new ones show up sometime around this weekend. Tonight, at first it didnt want to start.. took a couple tries. Seemed a bit rough but made a quick ride and came back, things seemed to smooth out... parked the car. The fuse buddy showed up late and of course I was too curious to wait had to know. Again it didn't start on the first try, but after it got running, it smoothed out OK. I never left the garage, just checked the amp draw. I let it sit for an hour, came back out and then it just plain wouldn't start, 4 or 5 tries. Pulled the safety switch and the fuel pump would not run. Pulled the same relay (upper).. jumped the connection and the pump kicks in. Put the same relay back in place and it fired up fine, easily. So this relay (used to be the horn relay) is now sticking perhaps? So this is now two relays acting troublesome and a blown fuse. Other than replace both fuel pump relays with new relays and see how it goes, I'm not sure what else to investigate. I also still dont have a cause for the blown fuse. All this happened in the driveway at idle so not thinking broken motor mounts letting the engine tug at something electrical to be the cause (this was a long shot anyway yes?) Any specific thoughts?
"this was a long shot anyway yes?" Yes. And TWO bad relays also seems like a long shot but possible, I guess. I have never seriously looked at my 328's relays since they have never given me any reason to but you should be able to open them and examine the primary contacts for pitting/corrosion that might be causing an intermittent connection. I would do that even though you have new relays on the way. If the contacts are in bad condition or not closing positively, that could cause the problem. By checking them, you will have a better feel for whether the relays are causing the problem or not. Of course, installing the new ones will fix the problem IF it is the relay(s) but it would be helpful to have an indication of what to expect. IOW, if you check the relays for good, positive contact and they seem OK, it would be prudent to expect that the new relays may NOT solve the problem. Another possibility - the circuit providing the relay coil voltage could be faulty - IOW, not consistently supplying sufficient voltage to the coil and, therefore, not activating the relay or causing it to "chatter." That could blow a fuse if the pump is rapidly tuned on/off/on by the relay.
I completely agree this is all too much of a coincidence to just let go and hope for the best.. it is possible, but not sitting well with me as an assumption. It just feels like a time bomb ready to go off again at the least opportune time.. Isn't the upper fuel pump relay triggered by the safety switch? (IE that's providing voltage to the coil) If not what does provide that voltage? If so, Is the safety switch potentially still the root cause? How would I troubleshoot that? I still have the original bad relay on my desk at home. I'll open in tonight and have a look.
Just leave the safety switch unplugged -- if the fuel pump ever doesn't run with the key "on", or the fuse blows = the trouble is something else. (Of course, the safety feature will be disabled so drive carefully and only do this as a temporary test.)
One other thing I have seen is that the circuit board on 328s sometime separate. My tech showed me one. They are 3 layer boards delaminate and cause intermittent problems as the traces make and brake contact. Since the problem seems to come and go when you mess with the fuse/relay board that might have something to do with it.
I have to admit that I have run with the safety switch disconnected for at least 10 years. It's my old drag strip days - I want to hear the fuel pump running when I turn on the ignition key. I'm not suggesting it's a good idea, it is, after all as Steve pointed out, a "SAFETY" switch. So probably best left to work as designed. FWIW, my understanding of its function is that it shuts off the fuel automatically if the car overturns so I remind myself regularly to take pains NOT to overturn the car.
So here is my road map. Check bad relay for internal degradation Replace relay(s) (Actually I have no proof there was ever an issue with the lower fuel pump relay, just got a couple of each type) Run for a couple weeks as normal... watch for trouble. If trouble starts back up... pull safety switch... continue to drive for a couple weeks.. If trouble continues investigate circuit board behind relays. By then you will have heard something from me and hopefully have a direction... If anyone suggests a different sequence I'm all ears.
