Battery Suggestions?

[Seymour Snerd]

Yeah I'm assuming the schematic is correct in this respect, which in a way is silly because the actual wiring is very different than what is shown on page 1 of the schematic with respect to the two maxi-fuses, etc. But, it's an easy thing to test.

 

[Steve C]

My 2c Re the battery and correction of AlanW's 9/12/11 post Re my MSD box

I use an Odyssey PC1200 (1200 cranking amps for 5 sec, 44AH).Great battery

The MSD is a "6ALN". The back is NOT removed. The PWB assembly is conformally coated to prevent moisture damage (this is what causes most problems with an MSD box) and has a clear plastic back.

I also use an MDS "vibration resistant" coil (it is epoxy filled not oil). Allows mounting in any position (I have vertiicle in P2125) and much less likely to short out under vibration.

Steve P2125

 

[Ron R.]

A little more follow up.

First, I just bought an Odyssey PC1200...Much larger than the battery I have now, and will require that I reposition the MSD, but I couldn't take having to worry about the car not starting whenever I went anywhere.

Now the interesting part.

Previously, I had wondered aloud if the rad fans might run on, even with the key removed, thereby killing my battery. (EDIT) It turns out that the radiator fan will run until the thermostat tells it not to.

In my case, interior vent fan will not always turn off. It seems that once it is on, it doesn't want to turn off. Perhaps the combination of the two fans running on is what killed my battery. Time to install a kill switch.

 

[Ron R.]

So, in speaking with somebody "in the know"...

The radiator fans will run until the thermostat tells them not to.

and

If the interior fan doesn't want to turn off, splice in a resister to the wire supplying the low speed setting. Radio shack part number 2761141, I think he said it was a "3 amp 50 PRV" resister (whatever that means).

There it is, my small contribution to the forum...repeating information told to me by someone who knows what they are doing. (btw, I would like to give credit where credit is due, the Olthoff shop is the "go-to" shop for all things SPF. I'm sure that there are others, but they've always been very helpful).

 

[Seymour Snerd]

It seems that once they are on, they don't want to turn off. I found that if I flipped the switches a few times, the will go off, but odds are that I didn't notice the first couple of times, and they killed my battery.

This is just a wild-ass guess, but the factory had some trouble with the engine refusing to turn off, and issues a couple TSBs before they (supposedly) fixed it. It had to do with the desire to keep the rad fan running when A/C is on even if the coolant temp was not high. So, is any of this behavior changed when you turn on or off the A/C?

The second TSB has you remove the effects of the first TSB. Perhaps you have some combination of the two that does not work? <shrug>

Just for reference:

View attachment 0601GT Engine Run On.pdf

View attachment GT40 Fuse 12 Service Bulletin.pdf

 

[Ron R.]

Alan,

Thanks, something else to check.

BTW, both parking brakes were rattling around loose, placed a call to Ipsco today.

 

[Seymour Snerd]

Alan,
BTW, both parking brakes were rattling around loose, placed a call to Ipsco today.

Cool, let me know how that goes. BTW I can't remember if I mentioned this but I discovered recently that installing the parking calipers so the cables exit to the bottom worked much better with my Mk II. With the cables on top there wasn't any practical way to close the rear clip without bending the cables to a ridiculous degree, without cutting up the clip. Now, if you were willing to have the cables shortened (or have shorter ones made up) that might be another matter. IAE swapping sides solved my immediate problem requiring only that I tie the outer cables to a couple handy holes in the bell housing to keep the cables well clear of the road.

 

[Seymour Snerd]

So, in speaking with somebody "in the know"...

The radiator fans will run until the thermostat tells them not to.

and

If the interior fan doesn't want to turn off, splice in a resister to the wire supplying the low speed setting. Radio shack part number 2761141, I think he said it was a "3 amp 50 PRV" resister (whatever that means).

There it is, my small contribution to the forum...repeating information told to me by someone who knows what they are doing. (btw, I would like to give credit where credit is due, the Olthoff shop is the "go-to" shop for all things SPF. I'm sure that there are others, but they've always been very helpful).

Very cool to know. By the way that $1.59-for-two part is a diode, not a resistor, so that confirms we have another "back feed" problem like the one that kept the ignition on. The "3A 50 PRV" text means it can handle 3A current befor overheating, and that in the reverse direction it can handle 50V before breaking down and losing it's "one-way" diode property. It's just a one-way valve for electricity.

Also, given it's a diode it matters very much which way it "points". You want the stripe on the diode on the side where the "load" (the blower) is. The current flows into the blank end and out the striped end. Never fear: if you put it in backwards it will simply keep the blower from running at all.

3A seems a little small for a blower motor so when the diode's installed let the blower run for 20 seconds and then feel for the heat of the diode body (carefully). If it's too hot to touch for a couple seconds I would advise adding another in parallel (there are two in the package). If two isn't enough or you'd rather use a single bigger diode let me know; I can find a good part for that.

Regarding "The radiator fans will run until the thermostat tells them not to" does he mean even with the ignition off???

 

[Jack Houpe]

Ron the switch has 4 wires on it, you may have a bad switch or maybe a couple of wires are on the wrong post. When you look at the switch are any of the wires black on the terminal from excessive heat? I changed my switch and control for the blower motors before SPF came up with a modified system bypassing the key switch. I used a pulse width modulator (you can buy them on ebay $30) that was good for 30 amps, the speed control for both blowers was done via a rheostat on the dash where the old switch was.

 

[Ron R.]

Very cool to know. By the way that $1.59-for-two part is a diode, not a resistor, so that confirms we have another "back feed" problem like the one that kept the ignition on. The "3A 50 PRV" text means it can handle 3A current befor overheating, and that in the reverse direction it can handle 50V before breaking down and losing it's "one-way" diode property. It's just a one-way valve for electricity.

Also, given it's a diode it matters very much which way it "points". You want the stripe on the diode on the side where the "load" (the blower) is. The current flows into the blank end and out the striped end. Never fear: if you put it in backwards it will simply keep the blower from running at all.

3A seems a little small for a blower motor so when the diode's installed let the blower run for 20 seconds and then feel for the heat of the diode body (carefully). If it's too hot to touch for a couple seconds I would advise adding another in parallel (there are two in the package). If two isn't enough or you'd rather use a single bigger diode let me know; I can find a good part for that.

Regarding "The radiator fans will run until the thermostat tells them not to" does he mean even with the ignition off???

Thanks for the info re: the diode. Makes sense.

And yes, the fans will run with the ignition off, and the key in your pocket. It makes little sense to me to wire it that way. With the engine off, the coolant isn't circulating, and you're only cooing whats in the radiator. Like I said, just another reason to put in a "kill" switch.

 

[Ron R.]

Ron the switch has 4 wires on it, you may have a bad switch or maybe a couple of wires are on the wrong post. When you look at the switch are any of the wires black on the terminal from excessive heat? I changed my switch and control for the blower motors before SPF came up with a modified system bypassing the key switch. I used a pulse width modulator (you can buy them on ebay $30) that was good for 30 amps, the speed control for both blowers was done via a rheostat on the dash where the old switch was.

I like that idea. Probably more involved than I have time to deal with right now, but I would like a continuously variable control. Something else to add to my "to do" list.

 

[Seymour Snerd]

And yes, the fans will run with the ignition off, and the key in your pocket. .

I'm just surprised because I "simulated" radfans on by shorting the two sensor wires together, and in that scenario my ignition switched turned the fans on and off. And that's also consistent with the wiring diagram. I'd love to know what other's experience is....

 

[Ron R.]

I'm just surprised because I "simulated" radfans on by shorting the two sensor wires together, and in that scenario my ignition switched turned the fans on and off. And that's also consistent with the wiring diagram. I'd love to know what other's experience is....

Nothing would surprise me.

That said, I can say my car's fans will absolutely run with the key in my hand, and everything set to off. Has happened several times.

Also, Olthoff's shop knew right away what the problem with the interior fan was...another feedback issue, and only took a minute to find the correct diode that I needed. That suggests to me that this has been an issue with a number of cars.

 

[Seymour Snerd]

Drift to cooling fan behavior

I'm just surprised because I "simulated" radfans on by shorting the two sensor wires together, and in that scenario my ignition switched turned the fans on and off. And that's also consistent with the wiring diagram. I'd love to know what other's experience is....

I have to eat crow on this one. I just fired mine up and let it heat until the fans went on. When I turned off the key, they stayed on. So my "simulatioin" wasn't, and either I'm not reading the electrical diagram right or it's not representing how the thing's wired.

IAE, SPF owners be aware that if you park your hot car and walk away it may sit there and run your battery down.

 

[Ron R.]

"IAE, SPF owners be aware that if you park your hot car and walk away it may sit there and run your battery down."

Yep, and despite having put a larger PC1200 battery in it, I still attach the charger when I can. Guess I'm a little afraid of being stranded, but I haven't had any issues since.

The plan has always been to put a "kill switch" in, and that should cure the problem once and for all.

 

[Jack Houpe]

I have a master kill just under my key, it kills the entire electrical system, but my battery is in the passenger foot well.

 

[Ron R.]

Jack,

Interesting. I'm going to put my brake ballance adjuster there.

What prompted you to put the battery in the footwell? I assume weight wasn't a factor.

 

[Jack Houpe]

It did transfer the weight to the front of the car and on the passenger side which is normally vacant. My wife is afraid of the car.

It was Mike Trustys idea and I followed his suggestion, he did the same.

 

[Rich E.]

Ron, bringing this topic back since I've just killed the battery in my car. The way my car is wired IGN Off means everything turns off. The only draw I have is my GPS tracker when I walk away from the car which pulls a very small amount of current. If you could do it all over again would you feel safe with the PC680? I really like the idea of putting my MSD box in the battery well but, like you, don't want it to strand me. I'm thinking of this:

Deka ETX20L Power Sports AGM Battery

Rich.

 

[Mike]

How about these?

LFX36L3-BS12 - Shorai Lithium Batteries