I'm starting to seriously think about rewiring my Bronco. My plan is to do my EFI swap, then rewire. I have one set of questions right now. I was hoping to finish wiring and see how the truck "acts", but I'm curious now. And the more I know, the easier my rewire will go.

I installed a custom built 200 amp, 3G alternator last winter. Its rated at like 100+ amps at idle. I'm running a dual purpose AGM battery (Deca - Intimidator - I think is the name). A pretty kick ass charging system.

All the voltage readings I'm referring to are from the truck's volt meter (a 4 month old, aftermarket Auto Gage), not a multimeter. Its wired to a switched circuit, I can't remember which. Where should I wire it, when I rewire?

What is the meter reading? available volts from the battery? or what the alternator is putting out?

Why does my meter drop below 12v (11.5 +/-) when I'm running higher amp stuff (fans, lights, etc)? I thought with the new alt, I'd always have 14+ volts (my 06 Chrysler, always reads above 14v). If I turn the stuff on before the meter reads 14v, it never gets to 14v. If the meter is reading over 14v and I turn stuff on, the volts slowly drop to 11.5v. When I turn off the lights or fan, the voltage jumps above 12v and slowly rises to 14+v.

I don't have an alternator light wired into the circuit, I was going to do that when rewiring. I've never had any problem draining the battery, but this battery is amazing. I had a ground problem with my alt last winter & it wasn't charging, but it would run for WEEKS before showing signs of low charge. I don't run that much at night, but the headlights seem to cause the worst readings.

If something is wrong, my guess is that when the hi amp stuff is turned on, the alt is not getting the proper voltage & is not "on".

Any ideas, or am I making something out of nothing?

Chad

Available battery voltage and alternator output voltage are really the same thing unless the alt output wiring is too small. The stock alt output wire is too small. You should be running it directly to the battery.

Gauge voltage can read low with other devices on if the circuit it's measuring voltage on is too small for the load it's carrying. This is common with the stock underdash wiring. Excessive resistance drops voltage.

Great info. My alt is run directly to the battery & I used a heavy gauge wire (10g I think), recommended by the guy who built my alternator. Sounds like when I rewire, I can do a better job "organizing" where extra accessories go. You are probably right that the meter is sharing a circuit with too much other stuff. Hopefully when things are cleaned up, the gauge will read more accurate.

I'm starting to fear my wiring. The fuse that runs my heater fan has melted the solder from one end, causing an open circuit a few times in the last year or two. The fuse is still intact (it has never blown), and after the fuse cools, many times it re-solders itself & works, other times I've had to replace the fuse. That is one reason I just swapped in a new fan, but it ohm'd the same as the old one, so I think its the wiring, not the fan motor. I haven't had the new motor in long enough to see if the melted fuse phenomenon will reoccur. I did put a smaller fuse (15a) in place of the 20a, just for good measure.

Thanks,
Chad

10 ga is too small to carry 200 amps. 6 ga is better. Keep it short and use good terminals.

Resistance at the fuse clips (probably due to rust) is causing the heater fuse to get hot. I replaced mine with a circuit breaker to prevent the same thing from happening.

Cool, I'll upgrade the alt wire when I rewire. I just bought a NIB Centech kit from a CB.com member. I was going to buy a generic hot rod wire kit, but jumped on the Centech kit so I'd have waterproof & new EB connectors. I think it was worth the extra money. Probably be a lot easier to install being EB specific.

Glad to know others have experienced the melted fuse issue. That was a new one to me, and I was more than a little concerned. Also glad the problem will be replaced with new wiring, and I don't have to worry about a faulty dash switch, or other parts.

Chad

I had a Granada back in the 80's that would do the same thing to the heater fuse. I found that the problem was the fuse block. The wire was riveted to the fuse end but must have not had a good connection. I finally had to remove the fuse and attach a new power wire to bypass that terminal. It took me a while to troubleshoot it because it was melting the solder inside the fuse and not blowing the fuse.

I think my low voltage readings are a bigger problem than an overloaded circuit/inaccurate gauge. This morning I got to work & had been running my heater fan. The volt meter in the truck never went above 12v, so when I got to work, I grabbed a multimeter & checked the voltage at the battery (with the truck running). It was reading the same as the truck's gauge, 11.5v +/-. I also checked my alt wiring. I used 6 ga wire & soldered & shrink wrapped, good copper ring terminals, so I can't blame the wiring.

I briefly considered rewiring the truck before doing my EFI, but this afternoon my new RJM harness arrived. It has an alternator trigger wire, so I'm going to get the EFI installed & use this wire, instead of the green wire from the stock harness (it is also feeding the electric choke on the carb). I'll also wire in a light, so I can tell more easily if the alternator is "on". Maybe using the EFI harness, wired directly to the battery, will provide a more reliable voltage to trigger the alternator. Its my only guess as to why the alternator wouldn't be turning on when other accessories are on.

Well this is just great. After paying $35, and waiting 2.5 weeks to send the alternator to Canada for warranty, Ray Knight just wrote me to tell me the alternator bench tested fine for him. They are going to take it apart and look it over, so we'll see. When we put my truck on our Snap On D-Tac charging system analyzer the alternator showed as bad, the battery tested fine.

When I first posted this, the alternator seemed to turn off when I ran high amp stuff, like headlights, or the heater blower. By the time I did my EFI swap, the alternator wasn't turning on at all. I figured it was a bad ground or a problem with the stock harness. But I rebuilt and upgraded all my grounds, and used the green alternator trigger wire on the RJM harness, and the alt never turned on. I even installed an LED into the trigger wire, and it never turned off when the truck was running. I know Viperwolf said the LED wasn't the right kind of bulb, but I found an email from Ray when I bought the alternator suggesting I use an LED. Regardless if an LED or incandescent bulb is the correct indicator light, the alt isn't charging.

When I spoke to Ray about the failure, and described my problems (read above), he said it was pretty obvious his alt had failed and was over heating. I told him the powdercoating had crazed and cracked, and I thought that sounded like an overheating issue too. He agreed & said he had never seen his powdercoated alts crack/craze. Even the gold pulley on the alt was darker than new, and looked like it had gotten hot.

So between this mystery alternator problem, and my mystery EFI codes, I'm pretty much baffled. I guess if he says the alt is fine, I'll reinstall it, and drive the truck to Denver (I'll bring a few charged batteries to make the trip), and leave it with Phil when I go to AK in a month, hopefully he can figure this crap out. J/K.

Had to vent.

I would check all my grounds. engine to frame ground strap body to engine. body to frame.loose or dirty connections.

I thought the same thing, but I installed new grounds during my EFI swap, ran winch wire from the battery to frame, 8g from alt to frame, have a braided ground strap from frame to motor, and ran 10g from the body to the frame. All connectors were soldered & shrinkwrapped.

Jumper 12V directly to the green wire at the alternator and see if it works. I still don't like the LED.

Right, I'll try that, I was thinking I need to ohm all my new ground straps and check voltage at the green wire. It would be typical for my luck to have a bad RJM harness causing all these problems.

I never ran any indicator light till the last day or two before sending the alt back.

Before I swapped in the EFI, the alt was grounded to the block at the same point the block grounded to the battery.

Just before the swap, I tried moving those grounds because that ground point was getting greasy & covered in antifreeze (waterneck never sealed on my old Edelbrock intake, despite numerous different waternecks, install techniques, multiple gaskets, filing it flat, etc). But I moved them to the motor mount, and it didn't help.

Now the alt is grounded direct to the frame at the same point as the battery grounds to the frame. I did not ground the alt or battery direct to the block, I figured the frame to block strap would be fine. Should I also ground the alt to the block? I have a homemade York OBA mount that uses the upper alt bolt, and may prevent a good ground from the case to the block.

I can't do much till the alt comes back, but think about it.

If you've been following my other posts you'll already know this has turned into a debacle. I've been waiting for over 2 months to get my alt back from SVA.
viewtopic.php?f=4&t=3652&p=34001#p34001

Since that is another story, and this is a different thread, I thought I'd post up here, what I know.

The alt I sent back has tested good, multiple times, under load. I discussed possible problems with John @ SVA. The single v-belt was not slipping on his test bench, under load. He believes that the regulator pig tail had a faulty connection, that may be the the culprit. He has the pig tail, and I'm not sure why he couldn't verify it. He has replaced the regulator, resoldered the alt, and replaced the pig tail.

Really I don't know the truth, and may never know. He may have fixed a bad alt, and made an excuse with the pig tail, maybe to avoid paying the shipping costs. Until I get my alt back I'm still grabbing at straws.

I tried to install a regular Ford 3g, Mike generously donated, but when I tried, I realized I had sent to pig tail back with the alt. So now I'm off to the parts store to see if someone has one here. If not, I'm probably going to just keep waiting till I get my SVA alt back with the new pig tail. This has already cost me too much, and if I can't get the truck running this weekend, I'm going to save a few bucks and not order a new pig tail that will probably show up the same day as my SVA alt.

I guess this is going to fight me the whole way.

I found a wire pig tail, at Carquest. But the 95 Mustang alternator Mike gave me won't fit. It interferes with my homemade York OBA mounting bracket. I tried flipping the alt both ways, and without surgery to my OBA bracket, its just not going to work. So I can add another $13.00 and a few more hours of work to get nowhere.

Since I'm expecting my SVA alt back soon (hopefully, all fingers and toes crossed) I'm just going to wait. Who would have guessed that a large bodied alternator would fit on my OBA bracket, but a smaller bodied alternator would have issues? I didn't even have to do anything to make the large bodied alt fit when I installed it, it was like I built the bracket with the big alt in mind.

I guess I'm going to spend the afternoon doing something productive, cleaning up the dog poo that is emerging from the melting snow in my back yard.

Broke down and did some gorilla grinding and got Mike's 95 Mustang alternator in!!!!!!!!! But switching from singe groove, oversized alt pulley to regular double groove pulley = belts are all wrong size, and no parts stores are open here on Sunday. So I'm still not up and running, but a few steps closer. Wish I had not gotten frustrated and quit yesterday, maybe I could have gotten to Napa before it closed, maybe not.

Both my big 3g alt, and this smaller 3g alt don't swing in very far, and leave little belt adjustment available. They must be a bit larger than the stock ones, and interfere with the block before they bottom out the adjustment. For my big alt, I bought 3 sizes of belts to try, and only one would get tight, AND fit on, and even that was a tight squeeze to pull the belt over the pulleys. I guess that is what an extra 70 amps costs.

I was taking measurements for my new belts and now I don't think the double v-belt pulley is going to work. The overall depth of the pulley is much thicker than the stock double pulley on the crankshaft & water pump. I can use the inner one, closest to the alternator. But, sighting across the pulleys, the front most v-groove doesn't line up with the crankshaft & water pump pulley grooves.

The v-groove closest to the alternator/water pump/crank shaft looks pretty good, centered roughly 3/8" from the back of the pulley. But the 2nd v-groove on the alternator is centered about 1-5/16" vs 1-1/16" on the w/p & c/s. Should I even try to put a belt on? Or will it throw the belt or burn it up? I'm leaning towards not even trying it, and putting my large diameter single pulley back on, and forgetting the double set up.

Edit: I just looked up the RJM double pulley and it looks like the measurements are closer to my stock pulleys, so I may have an option there if my single large diameter pulley doesn't cut it.
http://www.rjminjectiontech.com/collect ... ual-v-belt

Exactly 2 months to the day, after shipping it out, I got my alternator back from SVA. I installed it, leaving the LED in the trigger wire. When I started it the dash volt meter hit 13V and crept to 14v, probably charging my somewhat dead battery. The LED never turned off, but the alt was obviously charging. I swapped the LED for a small incandescent bulb I had (#194- turnsignal bulb), and low and behold it turned off, indicating the alt was charging. FYI, apparently that Viper guy knows a thing or two about electronical stuff. LOL.

So I played around with a volt meter on the battery posts, watching & comparing readings to the volt meter in my dash. With my headlights on high, and my blower fan running on high, the voltage @ the battery never dropped below 12.43. When I turned the headlights off, leaving the blower on high, the readings slowly crept up, probably would have hit 14v, but I was getting tired of watching. The volt meter in my dash read very close to my battery readings, unless the blower was on, then the dash gauge read about .5V lower. Just running the headlights on high or low, the readings @ the battery read about 12.8-12.9. As soon as I turned off the headlights (and blower) the voltage quickly ran to 14.0 and hovered around 13.95-14.0. The whole time the indicator light never turned on. I'm guessing that my battery needs to be charged, and after some driving I'll retest things and see where my voltage falls.

Any time the voltage was below about 13.0, and I revved the motor, the belt squealed. I NEVER had the belt squeal before. I'm going to try tightening the belt a little tomorrow, but I'm betting I'll order a double v-belt pulley from RJM soon, because it seems this alt is now too much for a single belt, and I don't want to stress the w/p or alt bearings. John @ SVA said it ran fine for him w/only 1 v-belt, but I have a York A/C pump above my alt, and I probably have less contact surface than John was running. My belt only contacts my pulley from about 6 o'clock to 9 o'clock.

I really think my alternator was bad. I never had the belt squeal before (maybe my belt was tighter, but not that much), and by the time I returned the alt, the alt was not charging my truck at all. If a pig tail connection was bad, why would it start out only failing with the blower or head lights on, and then deteriorate to the point it would never charge? I guess heat from added load could cause the connection to fail, and then the failure could continue to deteriorate over time. Do the connections at the pigtail see a difference from added load, or are they just on or off? I just don't know, and it really doesn't matter now. But I like to KNOW what was wrong, so I can KNOW more and learn how to diagnose/fix things better in the future.

Finally, I can turn my attention back to my EFI codes and clean up my loose ends.

Double belt it and the voltage with blower and lights on should come up to near 14V. At 12.4V it's slipping some.

Cool, the belt is a bit looser than I thought, so I'll tighten it tomorrow. I'll still double belt it, can't hurt, and now I've got room with the Explorer water neck & 69 GTO upper radiator hose.

So yesterday I was working on my Bronco, and looked over at the box my alternator was returned to me in. I saw a packing list stuck to the outside, that I hadn't seen when I received it and opened it. Inside was a letter from John Jervelund@ SVA, addressed to me:


Sir, we are returning your HD alternator to you under warranty. A defective holder, positioned the brushes, so that they damaged the alternator. There is of course, no charge for the repair, and we apoogise for any inconvenience you have experienced.

WTF??? Just 24 hours before he shipped it back to me, we talked on the phone. He explained that the alternator had run flawlessly for him, multiple times. He even said resoldered, replaced the regulator, and pig tail harness at no charge, even thought there "was nothing wrong with the alternator".

What a piece of work.

I knew that my alternator was now acting differently than it ever had. Even when it worked, early on, it never sqealed the belt, it never dropped voltage when my rpms were high, indicating a slipping belt. I knew that a bad pigtail, like he suggested, wouldn't have caused the deteriorating performance I saw occuring.

So now it all makes a little more sense.

Yea.....a tool. Time to move on. Just drop on a new one with a good warrantee and be done with it.

I think this one is fine now, I don't think it was 100% when I bought it.

I just got my double v-belt pulley from RJM in the mail, I'll install that and I'm sure that will fix the belt slipping. I also have Mike's 95 Mustang alternator, for back up. I've found, the best insurance against something breaking, is having a back up handy.

Next time I'll deal locally, with Carquest or Napa, or WH or BCB. Hopefully there isn't a next time, anytime soon.

Found the right combo of pulleys & belts, finally!!!!!!!!!!!

Double v-belt pulley from RJM on the alt, and the right set of belts from Carquest. Headlights on high beam, blower fan on high, rpms at idle & higher. No squealing, volts never drop below 14.4v.

Only took 1 year 5+ months after buying a 3G alternator to get it right.

Also, built & installed a new starter wire from 2g winch wire, crimped, soldered, and shrink wrapped the terminals.

I shut her down after the good voltage readings, figured I'd end the work week on a high note!

One step forward, next step check my EFI codes.

Thats awesome news.