High Voltage Surge

[CFR__AND_SONS]

(09-21-2016 )Waterloo Wrote:  Get under the truck and check your cabling and wiring, especially where any exits the sleeper and along the frame rails. Secure anything you find lose or rubbing after inspecting. Also open the battery box and check to insure the connections are tight on the posts, and that all are connected as they are supposed to be, take your time and really look, I have missed connecting this one wire I have at times when working on the truck. Check your grounds, especially at the engine block, you should have one at your starter, you will need a flashlight. If you see any exposed cable, I would replace it, odds are it is green and not doing its job.

Then, it might be a good idea to look in the fuse panel, check the fuses for any signs of trouble, like scorching or melting. If you have a Prostar, there are fuses and relays under the hood and in the driverside sleeper compartment. Check those too.

Under the hood, look at the connections on your alternator, make sure nothing is rubbing or is exposed to the elements, a nicked wire, or connections are lose. I routinely check my wiring, from the firewall to the CAC. I like to use that liquid electrical tape if I find anything that has rubbed or any suspicious connectors and seal it from the elements. The stuff is fantastic, and can be used in a pinch. https://www.amazon.com/Permatex-85120-Li...rical+tape

If you find any wires or cables rubbing against something, you can either zip tie and secure them, or if you are not able to do that, wrap the cable or wire in some old heater hose and secure the hose around the cable or wiring with zip ties. This will protect the wiring or cable and let that old heater hose take the abuse. Just remember to secure it, and check periodically. Or, use this wire loom protector, I buy it in 100 foot boxes in various sizes... I was just under the truck and used about two feet of this and resecured a cable just yesterday. https://www.amazon.com/Support-Split-Fle...+protector

At the rear of the tractor, check your lighting connections. I just recently had to rewire my entire ass end. I had repaired it before from the previous owner, but it was to the point it was giving me issues elsewhere in the truck. I bought a Weatherpack connection kit from my local Car Quest Auto Parts store, here is the same kit http://www.jegs.com/p/JEGS-Performance-P...5/10002/-1

The OEM harness connections were shot, so I cut them off and installed the Weatherpacks, along with a new back up alarm. One thing I like to use too, is dialectic grease, you can get it in most auto parts stores. It is weather and waterproof. I like to get the large tube and keep it in a zip lock bag. Here is the stuff I use, great for outdoor satellite installs too... https://www.amazon.com/Dielectric-Waterp...ric+grease

Also, the dialectic grease, I like to use it on my battery connections, the posts, smear it on there, not to heavy, but enough to cover the nuts. It eliminates the corrosion at the posts, and is cheap insurance. And when splicing wires, if you do not solder and use but connectors, I use the grease or silicone caulk in the connection ends, insert wire and crimp, then use the shrink tube over that to seal from the elements.

Another thing, and this has been discussed numerous times here... It is a good idea to replace your fuses, as they lose their effectiveness over time. They do not blow, they just lose their mojo, especially these cheap Chinese ones. I have some of the mini fuses that I have to replace every few months, especially the one for my AC blower motor. These are the Mini ATM fuses, in 5A, 10A and 30A. I am also replacing all of the OEM resettable fuses, will pick them up tomorrow from the dealer... Having electrical issues myself... Narrowed it down to the fuses, I am replacing all, including the relays.

I just bought a box of each of these, Bussmann, better quality and a good price on Amazon...

https://www.amazon.com/gp/product/B004AH...UTF8&psc=1

https://www.amazon.com/gp/product/B004AH...UTF8&psc=1

https://www.amazon.com/gp/product/B009WQ...UTF8&psc=1

I hope this helps you. This is pretty much what I do when I believe I have electrical issues. So far so good, and I have not had to visit any mechanics for anything more than to slap their computer on my truck to tell me where to look, or what module to replace. Then I go home and fix the problem myself, to know it is done right and to inspect for other issues near the problem... They usually come in threes on my truck.

Good luck!

Awesome info! Thank you very much. I'll start checking.

[Waterloo]

My voltage with the old and failed Delco alternator was 14+, the Leece-Neville is running around 13.8/9 volts... I think I made a wise decision going back to the OEM alternator. Oh, East Penn AGM batteries on mine... And another AGM battery on an isolator in my sleeper closet to help with the 3400 watt sound system... ;-)

[Rawze]

I had a truck that spiked to 15+ every time it rained. We complained about it every time we went to the main terminal of the company we worked for, but they kept ignoring it.

The alternator was the cause, we knew this, but no one believed us.

We went through a monsoon rainstorm one time and it went all the way up to 17.9 volts and burned out all the lights, the dash, and half the ECM. Good thing it was a company truck.

[CFR__AND_SONS]

(09-21-2016 )Rawze Wrote:  I had a truck that spiked to 15+ every time it rained. We complained about it every time we went to the main terminal of the company we worked for, but they kept ignoring it.

The alternator was the cause, we knew this, but no one believed us.

We went through a monsoon rainstorm one time and it went all the way up to 17.9 volts and burned out all the lights, the dash, and half the ECM. Good thing it was a company truck.

The electric guy was very busy after the rain yesterday.

Turns out that everything is charging as it should. Only thing that we found was a bridge at one of the batteries was not connected properly. So we are assuming that moisture got into the alternator which caused the spike. I'm gonna keep an eye on it and plan on buying a new OEM alternator, although this delco looks fairly new.

[overshot]

I has some peterbilts do the same thing when it rained or running in slushy snow. It was the alternator on all 3. Being out in the oil field or frequently in dusty or dirty atmosphere (hell I didn't even know I could spell that) tend to sandpaper the inside component insulation. Add water and boom you have a problem.

[Dcolumbia]

14.5 is too high. if you are regularly running 14.8 then eventually you will burn up the batteries due to over charging. Your voltage gauge could be showing 14.5 but actually be charging less. always check this at the batteries. Mine would spike mostly while it was raining and they are all right, it was the voltage regulator in the alternator. Changed it out and now it runs between 13.5 and 14 always, no spikes. This did not start happening until I had the engine washed for the first time. Probably coincidental I am sure and continued doing it during rain storms for about 8 months until it finally annoyed me enough to change the alternator.

[Rawze]

(09-23-2016 )Dcolumbia Wrote:  14.5 is too high. if you are regularly running 14.8 then eventually you will burn up the batteries due to over charging. Your voltage gauge could be showing 14.5 but actually be charging less. always check this at the batteries. Mine would spike mostly while it was raining and they are all right, it was the voltage regulator in the alternator. Changed it out and now it runs between 13.5 and 14 always, no spikes. This did not start happening until I had the engine washed for the first time. Probably coincidental I am sure and continued doing it during rain storms for about 8 months until it finally annoyed me enough to change the alternator.

The voltage is important depending on what type of batteries you have.

Cheap-o lead acid batteries -- 134.8 Volts is optimum, and they can take 14.2 max.

Glass-matts -- 13.2 Volts is optimum, and 13.8 is max. 14+ will shorten their lifespan.

Gell-Cells -- 13.2 Volts is optuimum, and 13.6 ids MAX. Anything above this, and you cook them and they typically go bad in less than a year. They also REQUIRE the Alternator "sense" wire to be hooked up, and not be jumpered out for correct charging.

Those numbers are from just my own experience,.. NOT from the battery data-sheets. This is what I have seen with others trucks out there.

[CFR__AND_SONS]

I went to the dealership to buy some parts and asked about the alternator. They looked it up with the vin and the guy said it's a high temperature application and it costs over $800.that's a pretty penny right there! Are they pulling my leg?

[Waterloo]

High temp? Where is it mounted, between the turbo and the manifold under the exhaust? That sounds like BS. I just paid $530 for a brand new Leece-Neville, 160 amp. The Delco was about the same, even next door at FleetPride... A reman Delco was around $370. Anymore than those prices and they are screwing you. Unless it is a high AMP unit, which then I would say is a good price. The high amp alternator for my truck runs $1700 for a new one. Glad mine takes the 160 amp.