BJ8 Tachometer, "sparking"

[pkmh]

BJ8 Tachometer, "sparking"

Hello Forum,

Need advice. Brief history first.

Let me say that so far, my tach has never worked from day one. That has to be my first given.

I know the car was converted from positive to negative, so everything that needed to be converted was done so. Generator, fuel pump, motors, etc, all work now. One of my last electrical woes (beside signals, not related to negative setup) is my tach.

Before having removed my wood veneer dash for refinishing (under another post), I had tried reversing that white [polarity] wire only, to see if the tach would work. Nada! I do understand there is or may be something else inside the tach, like a capacitor or transister that also needs to be switched. Well, instead of me trying to fiddle with that, I was going to test to see if there was power going to the tach or hot lead before even thinking what the next step would be for me.

Then I decided to remove the dash. When all went back together again, I noticed how the tach sparked, but just a couple of times (slight sound and illumination from below) I decided to disconnect the hot lead. No more spark.

Never had this happen before and am now wondering if by chance, I inadvertently fixed (or even created) some short when I reconnected all the gauges back. There is a ground wire that gets connected to the back of each gauge or so I thought. I have four gauges (fuel, oil/temp, speedometer and tach) and "five" grounds. I got a funny feeling there is this fifth which was never connected but where it goes to I am not sure. Right now, I have two grounded connections going to the back of the the oil/temp gauge. If that decision of mine is incorrect, then I have an extra ground and have no idea where that goes to.

My plan was to check for power to the tach or cross the white wire and see what happens. But now I have this intermittent sparking condition.

My future attempts is to send the tach out, but I want to be sure I have power going to it, first. Now this sparking issue has me wondering what the next step should be. I am tempted to try crossing the white wire and "hope for the best." Maybe I'll get lucky and my tach will work.

Any thoughts or anyone having had this kind of condition?

Paul

 

[pkmh]

Re: BJ8 Tachometer, "sparking"

Hello and so quick, I know.

I figure I respond before anyone attempts to, to my above problem.

I just took the Healey out for a quick spin and discovered that "sparking" sound emanating from behind the dash again. With the hot lead disconnected from the tach, I must believe I have created a short somewhere else and may not be coming from the tach.

What I feel I need to do is reinspect all my connections to all gauges and or check for a possible breach in one of the harness wires.

In the meantime, if anyone can offer a confirmation where that fifth ground is suppose to go, I would appreciate learning that.

My apologies for any confusion created.

Paul

 

[Keoke]

Re: BJ8 Tachometer, "sparking"

know the car was converted from positive to negative, so everything that needed to be converted was done so. Generator, fuel pump, motors, etc, all work now. One of my last electrical woes (beside signals, not related to negative setup)

is my tach.YES THE TACH IS ELECTRONIC AND IS POLARITY SENSETIVE:
your best bet is to send it to Nisonger for conversion and repair.Fwiw--Keoke

 

[BJ8Healeys]

Re: BJ8 Tachometer, "sparking"

Then I decided to remove the dash. When all went back together again, I noticed how the tach sparked, but just a couple of times (slight sound and illumination from below) I decided to disconnect the hot lead. No more spark.

Never had this happen before and am now wondering if by chance, I inadvertently fixed (or even created) some short when I reconnected all the gauges back. There is a ground wire that gets connected to the back of each gauge or so I thought. I have four gauges (fuel, oil/temp, speedometer and tach) and "five" grounds. I got a funny feeling there is this fifth which was never connected but where it goes to I am not sure. Right now, I have two grounded connections going to the back of the the oil/temp gauge. If that decision of mine is incorrect, then I have an extra ground and have no idea where that goes to.

My plan was to check for power to the tach or cross the white wire and see what happens. But now I have this intermittent sparking condition.

My future attempts is to send the tach out, but I want to be sure I have power going to it, first. Now this sparking issue has me wondering what the next step should be. I am tempted to try crossing the white wire and "hope for the best." Maybe I'll get lucky and my tach will work.

Any thoughts or anyone having had this kind of condition?

Paul

Paul, the wood dash is not a good electrical path, so each gauge needs a separate ground wire. I have the five ground connections, with two of them connected to one mounting post of the tachometer. I don't know where the fifth wire goes (it disappears toward the ignition switch behind the console), but it just uses the inboard tachometer post as a convenient grounding connection. If you have two of the wires connected to another gauge, it doesn't matter as long as all five are connected to a ground point somewhere.
Reversing the white wire on the back of the tach can be confusing. Are you sure you did it correctly?
To reposition the needle on the oil pressure gauge, you just need to remove the chrome ring, the glass, etc. to get to the needle, then pull it off (carefully) and put it back on, pointing to zero.
Converting the tachometer to negative ground is not difficult, but you need the ability to solder. There are two connections inside that need to be reversed. I can provide more detail about that, as well as reversing the white wire loop, if you contact me directly: sbyers@ec.rr.com
I'm not sure what "sparking" you are seeing. To check to see if power is getting to the tach, pull off the green wire and measure between it and a good ground with the ignition switch on. If you get 12 volts, then power is available to the tach. If your fuel gauge is working, then you should be getting 12 volts at the tach because they use the same green wire.

 

[pkmh]

Re: BJ8 Tachometer, "sparking"

Thanks Keoke for the name of the individual who rebuilds tachometers. I also know of one from Mamarineck, NY. Maybe the same person. I will look into for future, if necessary.

Thanks Steve for your help as well. I'll be contacting you soon. Hope the pics work. Let me know otherwise.

Much appreciated!

Paul

 

[pkmh]

Re: BJ8 Tachometer, "sparking"

Just want to say thanks to Steve above for his insight and knowledge on providing step by step instructions on how to do the simple task of converting my tach's current positive setup to a negative one, which was nothing more than de-soldering the resistor to the main lead and the green wire from the 'rivet' and switching the two (or that is to say, crossing by now soldering the resistor to the rivet and soldering the green wire to the main lead). Both are found underneath the phenalic insulator, which is represented by a flat slab-like material and which the main lead connector and rivet are fastened to.

Because I found it difficult to de-solder the rigid wire extending from the resistor, I simply made a cut into the wire as close as possible to the main lead's weld, and then curled back and soldered to the rivet. The green wire was a simple task of de-soldering and then soldering to the main lead.

My tach is now responding, although the needle is registering high at around 1500rpm during "normal idle." To correct this, I must now adjust the RPM's idle by turning the black round disk's slotted screw which is used to recalibrate. Not sure what this is referred to by name, but may be beneficial to provide a cutout just large enough to the housing over this component and then place a rubber grommet to seal as well as provide easy access for future calibrations.

I will approximate the correct position of the true rpm's, maybe figure a factor of safety so as to not potentially cause engine damage. I have no interest in maxing out the red line for each shift so I will be satified.

Thanks again Steve, for all your help!!

Paul

PS. The "sparking" I was experiencing, which I believe is correctly referred to as, "arcing", was the result of a lose wire currently found near the footwell area. Haven't figured out what this [red] wire was suppose to go to, yet, though I believe it may go to the radio. So, for the moment it is capped until I can get to it later.

 

[TimK]

Re: BJ8 Tachometer, "sparking"

I have a similar stray extra red "hot" wire that probably also went to a long gone radio. I plan to use it for a 12 volt accessory plug that I will wire negative (isolated from chassis) polarity.

 

[pkmh]

Re: BJ8 Tachometer, "sparking"

Tim,

Let me know of a site or if I can learn a bit about how to install a 12 volt accessory plug and the wiring setup for that, too.

Because I still do have a radio andwould like to hook that up, hopefully it is not a big deal to have both options left open to me.

Paul

 

[Bob_Spidell]

Re: BJ8 Tachometer, "sparking"

...

I must now adjust the RPM's idle by turning the black round disk's slotted screw which is used to recalibrate. Not sure what this is referred to by name ...

'Trimpot' (short for 'trimmer potentiometer'). It's a variable resistor.

Putting a rubber grommet/plug over the hole is a good idea; I just put some electrical tape over it.

 

[TimK]

Re: BJ8 Tachometer, "sparking"

Wiring is pretty simple (one wire goes to the positive post of the battery and the other to the chassis (which is connected to the negative post of the battery in your car). The only other consideration is do you want the item to be on all the time or only when the ignition key is on. If only with the ignition key, then you have to take your power from the key. Check your red wire with key on and key off to see if it goes through the key switch.
Because you have a negative ground system, all you have to do is buy an accessory plug and feed the red wire to the red wire on the recepticle and ground the black wire. I have to do the opposite (because I still have a postive ground system) and insulate the plug from the chassis. You also should add in in-line fuse between your red wire and the plug. Use a five amp fuse if you plan to plug in a gps or radar detector.

 

[pkmh]

Re: BJ8 Tachometer, "sparking"

...

I must now adjust the RPM's idle by turning the black round disk's slotted screw which is used to recalibrate. Not sure what this is referred to by name ...

'Trimpot' (short for 'trimmer potentiometer'). It's a variable resistor.

Putting a rubber grommet/plug over the hole is a good idea; I just put some electrical tape over it.

Thanks for that bit of knowledge. Electrical tape may have to do until I find the right size grommet, but that shouldn't be too hard.

 

[pkmh]

Re: BJ8 Tachometer, "sparking"

Wiring is pretty simple (one wire goes to the positive post of the battery and the other to the chassis (which is connected to the negative post of the battery in your car). The only other consideration is do you want the item to be on all the time or only when the ignition key is on. If only with the ignition key, then you have to take your power from the key. Check your red wire with key on and key off to see if it goes through the key switch.
Because you have a negative ground system, all you have to do is buy an accessory plug and feed the red wire to the red wire on the recepticle and ground the black wire. I have to do the opposite (because I still have a postive ground system) and insulate the plug from the chassis. You also should add in in-line fuse between your red wire and the plug. Use a five amp fuse if you plan to plug in a gps or radar detector.

If my car was still set up for positive ground, I would of left it that way, just to keep things original. But since the negative conversion was started, I'd figure I just follow through and finish it. Considering there is a [British Leyland] radio in my car, well...why not have one still (and hopefully it'll still work when I get to connecting it).

Thanks,

Paul

 

[BJ8Healeys]

Re: BJ8 Tachometer, "sparking"

Paul, your radio is probably still positive ground. Some old radios of that vintage had a switch on them where you could select either positive or negative ground operation. If yours doesn't have that option, to make it work with your (now) negative ground car you'll have to isolate the radio from the chassis.

J. C. Whitney used to sell a voltage "converter" that would change the input voltage to an output of opposite polarity. I bought a used one (Archer brand) from a vendor at a car show years ago, and used it with my modern radio before I converted my BJ8 to negative ground. I don't know if such things are still around. I may still have mine, but I think I sold it when I didn't need it any longer.

 

[pkmh]

Re: BJ8 Tachometer, "sparking"

Steve,

I kind of remember looking on the back of my radio for this switch I also heard about from someone else. I don't remember seeing anything in the way of a switch. But I will look again. Maybe I overlooked something and maybe I'll get lucky from a second look.

When you say that I'll have to isolate the radio from the chassis if the radio is still positive, then I guess if I try to go ahead and hook up the radio with what I have (red wire?), then I could fry the radio?

I'll post my findings if there are any to be found. Then I'll take it from there or post my findongs if results are positive.

Thanks,

Paul

 

[BJ8Healeys]

Re: BJ8 Tachometer, "sparking"

Yes, it's better not to try to hook up the radio as is. Some of those old radios also don't like to be powered up without the speaker load on them, too, so be sure you have speakers connected when you do turn it on.

I'm not sure the BMC radios installed in Healeys had the positive/negative switch, but some radios of that vintage did. On some radios, it was a typical switch, but on some it was a plug (with two metal prongs) that you removed and turned to another position to change the polarity.

 

[RAC68]

Re: BJ8 Tachometer, "sparking"

Hi Paul,

I had a BMC AM positive-ground radio in my BJ8P1 since new and it did NOT have a polarity switch. I am not sure if there were multiple BMC radio models installed in Healeys but, in retrospect, I would say it was not a great radio but probably equal to all the other AM radios of the time. Although I still have the radio (one of my prime modification laws - just in case I decide to revert), one of the reasons I changed polarity was to be able to install an AM/FM to actually hear something, other than the exhaust note, on long trips.

Ray (64BJ8P1)

 

[pkmh]

Re: BJ8 Tachometer, "sparking"

Gee, maybe I have one of those fancier radios installed. If my memory is correct, it does say British Leyland on the glass with five operable radio push buttons, two marked "AM" and the other three "FM".

Not sure how this radio is "programmed" sort-of-speak. That is, I know I can store stations as marked on the buttons, (i.e., 2 AM's and 3 FM's), or the option of 4 AM's and 4 FM's, also by selecting and pulling on the button to save a specific station.

Steve, any idea if it is just a matter of crossing wires to this plug as you mentioned above?

I should be able to pull out the radio console easy enough, so I will get back on this subject.

Thanks all,

Paul

PS: On another thought about grounding or isolating from the chassis, is it possible to create a 'floating ground' that's not part of the chassis? For example, pretend I have a wood or some other non-conductive bracket mounted to the chassis (or bulkhead, if you will), then apply a metallic mass to it and in turn ground the radio that way, maybe it would work?? (I am laughing now because I have no understanding of electrical know-how so I wonder if this idea is ridiculous or possible).

 

[BJ8Healeys]

Re: BJ8 Tachometer, "sparking"

Paul, the "plug" I referred to was a small circular thing with two metal prongs that you could insert in one of two orientations into the radio. I don't know what the prongs connected to inside. The two positions were marked "+" and "-". If your radio had such a thing, it would be obvious, and if you had it you wouldn't need to change anything inside the radio to change its polarity. That's what the plug did.
If your thought is that you could switch some connections inside your radio to accomplish the same thing as the plug, I don't know.
There were several different radios installed in BJ8s as optional equipment: Type R602.T, R900.T, R902.T, R70T, R920T, R970T, R470T, R972T are the ones I have recorded in the registry. These were identified on BMIHT certificates and usually were in "Personal Export Delivery" cars. If you find any model or other numbers on your radio when you remove it, please let me know what they are. I do think you have one of the fancier radios.
Thanks.

Even if you isolate the radio chassis from the car, you still have to figure out how to isolate the antenna, too. Doing it wrong can possibly melt some wiring in your car, or worse. I believe since you have a negative ground car and rudimentary electrical skills, you should install a negative ground radio and just keep the BMC in a box for the next owner. I got a very nice vintage Triumph radio (negative ground, AM/FM) for my BJ8. No one can see the Triumph logo unless they are in the car and look hard for it because it's under the buttons.

 

[RAC68]

Re: BJ8 Tachometer, "sparking"

Hi Paul/Steve,

I mentioned BMC which was formed with the merger of Morris and Austin in 1952. BMC, in turn, merged with Jaguar to form British Motor Holding in December of 1966 and then joined with Leyland in middle 1968. If your radio was manufactured by British Leyland, it was probably not supplied with your 1966 BJ8 from the factory or the dealer. However, since AM/FM radios began to appear at dealers in the very late ‘60s, and more frequently in the early ‘70s, it could easily have been a dealer purchase and install (as an AM upgrade or new installation). Additionally, since British cars sent to the USA in the early ‘70s were now commonly installed with negative grounds, I would expect, at that transition time, for British Leyland to have equipped their radios with a polarity switch to allow installation in all of their present cars as well as some past models.

As Steve noted, isolating a positive ground radio in a negative ground car will require totally isolating the radio and antenna from the car. Since the antenna must be grounded to the body and radio chassis, it will be an issue. However, I expect that others on the list have converted to negative ground with their previous radio and have found a solution. A friend mentioned he addressed the antenna issue by installing an electronic antenna and left the original mast in place to fill the hole.

Hope this helps,
Ray (64BJ8P1)

 

[BJ8Healeys]

Re: BJ8 Tachometer, "sparking"

Although I didn't comment on it, it was my thought, too, that a "British Leyland" radio was too late to be an original radio from the factory in a BJ8. I once had an original radio from a very late BJ8 and it had "British Motor Corporation" on the faceplate.

Anyway, from photos I don't see any polarity switch or plug on Paul's British Leyland radio.