Ideas needed-electrical nightmare out of nowhere (almost)

[knac1234]

All,

So after taking the Rover to the car wash yesterday and blasting all the mud from the inner fenders and giving it a quick clean, I decided to at the same time throw a plastic bag over the dizzy and alt and lightly spray the mud out of the engine compartment. Big mistake. :sly:

I ended up with no turn signals, no horn, the radio working on accessory position only and in the ignition position (unless the hi beams are on), the starter turning sloooowly (new hi torque starter) :mad:

Any ideas where to look? 2 fuses in the steering column were blown, but replacing them did nothing.

I can't believe I did this, and have no idea how (electrical system worked perfectly and had been gone through by me completely).

All ideas appreciated.....going to pull the instrument panel after breakfast to poke around.....

Thanks,
Julian

[artpeck]

I had a similar issue with my defender. My immediate "fix" was to put the truck in the hot sun and open the hood. Longer term fix was to go through every connection and clean and polish each and liberally coat with dielectric grease. No issues after that. Sorry I can't be more specific but it could be one of so many things. Oh and a radio??? Wow you drive in luxury. I don't think I could hear a radio even if I had one.

[jonnyc]

Radio??? I did have one once, and you're right....couldn't hear it.

I had a similar issue once when I went to a DIY carwash. Next time I did it with the engine running and the problem did not reappear.

[knac1234]

Well, I've taken the instrument panel off to look around, looked all over the truck.....no melted wires (this thing is fused to the hilt).

Still, the horn does not work and the indicators do not work. The hazards do work! I tested the flasher....fine.....didn't think it would be that, but to eliminate issues.

Going to pull out the wiring diagram.....see what the horn is linked to and start with that.....maybe it will tell a story.

Radio.....yes, I can hear it (barely!). Anyway, turning the key to the ACC pos and it works.....turn the key to the igntion position....it does not. But, when running a test lamp off both terminals, they are both live when they should be!!!!

Will keep checking if there are other ideas!

Julian

[knac1234]

OK,

So here's some more insight:

HORN: I disconnected the horn after finding power was getting to it, and ground it to the battery directly and powered it to the battery directly-tries to sound, but I think coincidentally the horn is toast.

TURN SIGNALS: I accidentally tested the hazard flasher unit.....then checked the turn signal flasher unit and found it was dead. Pulled the one out of MG.....turn signals now work.

HI BEAM: Perhaps the switch (horn, turn signal, hi beam) is also toast, but a couple years old only. Power was getting to the high beam wire up front at the lamps, but not the regular beam wire. I confirmed at the switch itself the same thing. So it appears that the blue wire from the headlamp switch feeding the power to the horn/turn signal/hi beam switch gives power, but it is not allowing power when on regular beams. Probably need a new horn/turn signal/hi beam switch. I may have a spare from my Imp that is the same to double check.

IGNITION WARNING LAMP: I noticed that these were not turning on when the key was in the ignition mode. The brown/yellow tracer wire to the ignition warning lamp is it's ground (I tested the bulb....fine....but it was getting no ground). When I ran a ground directly from the brown/yellow tracer wire at the alternator, it lit up fine.

OIL PRESSURE WARNING LIGHT: There is a white/brown tracer wire that grounds that lamp. Same as the ignition lamp.....it is not grounding. When I run a ground to the bulb it lights up properly as normal.

STEREO: Works when in ACC not in IGN mode. Ran it direct the battery and, when the car is running, it shuts down! I am thinking grounding issues.....something throwing off the grounds in the whole car??????????

So that's where I am now......any thoughts?

Thanks,
Julian

[bkreutz]

I'd suggest letting it dry out for a while, maybe the water is diluting the Lucas smoke.

[knac1234]

And one more.....

STEREO--So I removed it altogether so that the casing was not grounding to the chassis of the car and hence grounding the stereo. I grounded it directly to the battery along with the power cables......

-Stereo works when literally holding it in my hand hooked up as above, car running
-Stereo shuts down when I ground it to the chassis of the car, still holding it in my hand, still with the car running BUT when I shut down the car, the stereo works fine again

Could something be defeating the ground, or its effectiveness, on the car itself??????????

Julian

[artpeck]

Probably stating the obvious but have you looked to make sure the battery (-) to chassis ground strap is grounding consistently and effectively? Most of the time these thing are just old corroded connections that work and don't work intermittently.

[knac1234]

Art,

Thanks, but unfortunately not the issue. Ground strap new and tight. And the new starter was grounded directly to the battery via another new and tight cable.

There has to be something related to the ground running the ignition warning lamp and the ground running the oil pressure warning light. Too coincidental that both are not working unless the ground is run at either end (oil pressure switch end or alternator end) straight to the battery. At least that's this moments theory!

Julian
Julian

[SafeAirOne]

Julian,

The way the charge light works is that it "compares" the voltage on either side of the bulb. One side is (essentially) battery voltage, taken from the "hot in run" circuit from the ignition switch and the other side is alternator voltage. When there is a lower voltage (or no voltage) on the alternator side of the bulb, such as when the ignition is on but the engine isn't started yet, electricity will flow through the bulb through the alternator then to ground. When you start the engine and the alternator puts voltage down the charge lamp wire, the bulb will extinguish because the voltage on either side of the bulb is equal, cancelling out any flow of electricity through the bulb.

Presumably when the alternator is overcharging, the bulb will also illuminate from a greater voltage from the alternator causing electricity flow toward the ignition switch.

If the light is not illuminating with the ignition on and the engine off, I might check to see that the white wire to the fuse block didn't come off or that the alternator is properly grounded.


As for the oil pressure lamp--The way that works is that with low or no oil pressure, the oil pressure switch is closed, completing the circuit to ground causing the oil pressure light to illuminate such as when the ignition switch is on, but the engine is not running. Once you start the engine and a set oil pressure is reached (7 lbs, I think...) the oil pressure switch opens, breaking the circuit to the light.

Note that it has been my experience that the oil pressure switches on the 2.5s are prone to failure on a fairly regular basis. I'm on my third one in 5 years. It starts with the light NOT illuminating when the ignition is on and the engine is off and progresses to the oil light illuminating at idle, but going out at higher RPMs. I just replaced mine 2 weeks ago and it cured this problem (again). If you have 12 volts at the pressure switch with the ignition on, then the system is fine and the switch is bad. You can also check for NON-continuity between the terminal on the switch and ground with the engine shut off to confirm.

Oh...one more thing--Just because a ground strap is new and the fastener is tight doesn't necessarily mean that it is making a good electrical bond with whatever it's hitched to. You might disassemble, clean, re-assemble and seal up your grounds just to be sure. There should be several of them--Battery to chassis, chassis to block, starter to block and front harness to radiator support panel and possibly alternator to block, not to mention the negative terminal on the battery itself. The only thing that the alternator warning light circuit and the oil pressure light circuit have in common is their source of 12 volts (which you confirmed was present in both circuits) and the ground path between the engine and chassis and chassis to battery.



Overall, however, I'm kind of uneasy with all these seemingly separate things going coincidentally wrong at the same time. 2 blown fuses and all the stuff that uses thin metal reeds as electrical contacts failing simultaneously seems unlikely. I'll throw out the possiblility that some sort of brief but massive jolt was sent through some circuits, bonding the reed switch contacts together and blowing the fuses in the process. Something quick that wouldn't be there long enough to heat up wires to failure, but enough to spot weld the reed switches together. Just a theory, really...

[knac1234]

Mark,

Thanks for the explanation on the alt and oil pressure switch. Will check for 12V at the oil pressure switch. Clearly my oil pressure is fine per the gauge, so I'm not too worried about it, but want it to work like everything else!

The alternator.....that makes sense and explains how the ignition lamp goes from bright red (engine not running) to faint at idle on occasion to out altogether. Unfortunately, I am positive that NO wires have come off any terminal (I literally have the instrument panel hanging out and have checked every connection there, in the engine compartment, and even the left rear tub corner (removed the panel as that reverse lamp was out.....but it was just loose, and no relation to the other problems....).

Very frustrating, as, you may recall, I literally went through the entire electrical system several months back.....and all new connectors, bullet connectors, ground straps, etc.... were installed throughout.

I may get to it tonight, but kind of need to reassemble everything quickly as I had planned on driving the truck to Pikes Peak Rovers for a steering problem I've given up on :sly: She starts and runs fine, and is fused properly and to the point of overkill on the separate fuse box I installed, so at least that is in my favor!


Keep the thoughts coming. I don't believe in coincidences.....this happened all at once literally when I started her up to drive her out of the car wash that day!

Julian

[cedryck]

Small suggestion here, If you do wash the inside of your engine bay put an old plastic bag over the alt. and protect other sacred electrical devices as the fuse panel. Then, when finished use compressed air to blow off residual water, do not blow water into items, I like the idea of letting it dry out in the sun. My rover once stalled from a water crossing, it just got too wet. Now if I water cross, I refrain from shutting if off after. Cheers.

[knac1234]

Well, problem solved. Thanks to Mark (in another thread)....got me thinking about his comment about pulling the positive cable off of the battery. That sealed the deal. The truck died instantly, indicating that the alternator was not powering the truck independent of the battery and was toast.

Did I mention it's handy to have a few Brit classics?! Went to my Hillman Imp, pulled the Lucas alternator in 10 minutes, and fit it to the Series. Problem solved! Ignition lamp working......radio does not die.....starter starts quickly again....the only issue is the oil pressure light which I bet is a duff switch. I figure there was just enough juice in the battery to start it, explaining why even the radio might have lost power with it running....but was fine with it not....not enough juice to go around!

This means it is time to look into the alternator conversion previously brought up by me a few weeks back!

Thanks,
Julian

[SafeAirOne]

Well, problem solved. Thanks to Mark (in another thread)....got me thinking about his comment about pulling the positive cable off of the battery. That sealed the deal. The truck died instantly, indicating that the alternator was not powering the truck independent of the battery and was toast.

Glad to have (accidentally) helped you out. :D

Incidentally, just for the record, in the other thread, the poster on his own removed the battery cable and the engine died. Though I've done it more than once in my younger days, I woldn't recommend this procedure; Suddenly removing most of the load (the battery) from a healthy alternator that's cranking out the volts to meet that load has the potential to fry the alternator when that voltage/current suddenly has nowhere to go.

[knac1234]

Mark,

I had always heard that too (alternator could be fried by disconnecting the battery). But I'm glad I tried it this time! Just drove it 45 miles to Co Springs to have the steering looked at. Ran like a clock, started strongly first time this morning, and no other oddities like the radio dying. Poor Imp is alternator-less though right now!!!

Julian