All lights flashing very very bright!!

[85xjwoody]

I have an 85 wagoneer with a 2.5 engine, 904 tranny, and 229 tranfer case. I think that I have a serious electrical problem. When my jeep is running and I rev up the engine all the lights get extremely bright and flicker even brighter. I don't know much about electrical so I will try my best to answer any questions. I have not been on a trail ride with it since Memorial weekend when it went on the trailer due to rear axle damage. That weekend on the final day of wheeling I was having problems with my headlights, they would not come on at all neither on brights or normal. My running lights would come on but no headlights. A friend was messing with a wire in the engine compartment and my brights came on so we went for a trail ride to find my back axle was damaged so we went back to camp then home the next day. That friend can't make it to my house to show me which wire and I can't find it. Is there anyone out there who could help me with this problem. Any help is great. Thanks.

Kim.

 

[JJacobs]

Sounds like the voltage regulator built into the alternator is going out. Fix it quick, 12V electrics don't like 18-19V.

 

[85xjwoody]

Sounds like the voltage regulator built into the alternator is going out. Fix it quick, 12V electrics don't like 18-19V.

When I rev up the engine and the lights go bright they don't gradually get bright then get extremely bright instantly and my voltage meter stays just above 13V just like it always has. How do I fix the voltage regularor if it is built into the alternator? I have replaced a few alternators before but have never had to deal with the electric.

Kim.

 

[85xjwoody]

Can anyone tell me where the voltage regulator is? I cannot find it. Electrical is new to me.

Kim.

 

[8Mud]

I´m pretty sure you have a Delco alternator, V belt type. The regulator is mounted inside the case in the back, white odd shaped.
There is a test hole in the back of the early Delco, you can gently stick a screwdriver in the hole and then allow it to touch the case, this bypasses the regulator and gives you full unregulated voltage. Only do this for a moment with the engine running and have somebody watch the volt gauge. It should jump up to near the red, pretty quick.
Find somebody with a volt gauge and check voltage at the battery terminals. Like mentioned before, a runaway alternator, will/can cause serious troubles, burning out all the light bulbs, being the least of them.
If you have the Ford alternator, the regulater is mounted on the firewall, on some Jeeps.
A short that doesn´t blow a fuse, will sometimes cause a regulator to over charge the system, trying to compensate for the voltage lost through the short. Feeling the wiring for heat, is often a tipoff there is a short someplace.

 

[85xjwoody]

I´m pretty sure you have a Delco alternator, V belt type. The regulator is mounted inside the case in the back, white odd shaped.
There is a test hole in the back of the early Delco, you can gently stick a screwdriver in the hole and then allow it to touch the case, this bypasses the regulator and gives you full unregulated voltage. Only do this for a moment with the engine running and have somebody watch the volt gauge. It should jump up to near the red, pretty quick.
Find somebody with a volt gauge and check voltage at the battery terminals. Like mentioned before, a runaway alternator, will/can cause serious troubles, burning out all the light bulbs, being the least of them.
If you have the Ford alternator, the regulater is mounted on the firewall, on some Jeeps.
A short that doesn´t blow a fuse, will sometimes cause a regulator to over charge the system, trying to compensate for the voltage lost through the short. Feeling the wiring for heat, is often a tipoff there is a short someplace.

Thank for the help 8Mud!. This is all new to me so any help is awesome. My alternator is a replacement from Napa and is called a rayloc replacement alternator. It is under a two year warranty still. The alternator came with the v-pulley but had to switch the pulleys around since my 2.5 runs a serpentine belt. I don't have anybody around for a few days to help me test the alternator or have a tester for me to use. If it is the built in voltage regulator can I replace the alternator under warranty even with it not in the best shape having some mud on it? Never had to replace an alternator under warranty before. Any other suggestions or help is appreciated.

Kim.

 

[85xjwoody]

Ok everyone. I got my alternator off and the clay also had its way with that too so I will be replacing the alternator all together. I was looking at Advance Auto Parts web site and they have an alternator that is rated at 94 amps instead of 78. The part number is listed as A7194612. The part is from Autolite Pro. Is this upgrade worth $100.00 or not? I was thinking Mean Green but they want almost $400.00 for one. Will 94 amps be enough to run a winch plus a few accessories with a red top Optima?
I will be getting a winch soon enough and will be upgrading the wiring and battery for it. I don't know how to link the page I would like to show with the part on it so I apologize for that. Thanks for the help.

Kim.

 

[5-90]

When troubleshooting electrical issues like this, DO NOT rely on the gage in the dash panel - it's usually wrong.

ALWAYS use a good voltmeter or multimeter, and check alternator output at either the positive battery post or alternator output post. It's best to put the other terminal on a sheetmetal ground or the engine block - since that's where the alternator's grounded anyhow.

Anything up to about 15VDC is fine - more than that, and you're going to let the "magic blue smoke" out of something.

The regulator on the Delco is built into the back of the alternator case (it's where the little plug with several wires goes,) and Delco alternators are pretty cheap - unless you really want the practise, just go get one with a higher output rating and install that instead. Take the old one back to get your "core deposit" - kinda like the old deposit on longneck soda bottles.

For pricing, see if there's a local shop that does rewinds (that's what I do,) since you can score deals like, say, 150A for $75... AND get a part that's going to be done well, since you'll be dealing with the guy that does the rebuilding his very self. You just get all new parts in an old case (and, since the case doesn't wear out, you're getting an effectively new alternator for a used price. Rotor, field coils, bearings, brushes, regulator - all new. Pully and fan are probably old, but they don't wear out either.) My shop gives me good parts - the only time I need a new starter or alternator is when I buy a new XJ...

5-90

 

[85xjwoody]

Thanks for the info 5-90. Could you tell me more about doing the rebuild to get 140 amps out of my alternator please. That seems like the way to go. I will be running a winch soon and would like to upgrade the alternator now if possible. My alternator is toast. I took it apart and alot of clay got in there also so what do you think I should do? Go with the rebuild to get 140 amp or get the 94 amp alternator for $100.00? Let me know please.

Kim.

 

[5-90]

Oh - I don't do the rebuilds - I have them done for me. I can do them if I really need to, but Rod has all the tools that make it easier, and that saves me a couple hours each time I buy another XJ.

Like I said, find a local shop. The little "hole in the wall" places are best - Rod runs his shop (San Jose Generator) pretty much all by himself, and when I'm dealing with him, I'm going right to the source.

It also helps, once you find a shop like this, to send them as much business as you can (they always appreciate the help - I finally sent Rod enough that he's hired someone part-time) and you will probably notice your prices getting better as well (I've printed some of his cards on the back of my own - with his permission. He's nice like that...)

5-90

 

[85xjwoody]

Thanks again 5-90. I will look into trying to find a shop to do this. I knew that you didn't know how to do this just try to direct me in that direction. Thanks again.

Kim.

 

[langer1]

Thanks again 5-90. I will look into trying to find a shop to do this. I knew that you didn't know how to do this just try to direct me in that direction. Thanks again.

Kim.

It think what 5-50 meant was to by a used 150amp somewhere and have that rebuilt.

 

[85xjwoody]

It think what 5-50 meant was to by a used 150amp somewhere and have that rebuilt.

Where could I get a used 150 amp alternator? Specific vehicle? Will it bolt up directly or some mods involved. TIA

Kim.

 

[langer1]

Clean up your Napa one and take it back for now. Then you will have time to find a Hi-Power one.

 

[85xjwoody]

Clean up your Napa one and take it back for now. Then you will have time to find a Hi-Power one.

They told me it is not covered under warranty because the housing has been modified. The top bolt was stuck and so I had to drill it out to put in a new one. I told them that and they told me no warranty. So I will be looking into the hi-power alternator soon. Thanks again for the help.

Kim.

 

[5-90]

You don't even have to find one that started life as a 150A - you can get any Delco with a case that matches (and re-clock it if the mounting tabs are in the wrong place) and have that built to spec. I think half of the CS-120's I've got now started life down around 60-70A, and are now putting out at least twice that at full charge. That's just a matter of changing the rotor coil and the regulator/diodes so they don't melt down.

I can do the rebuilds if I have to - I just don't have the gear to make it easy. Rod can do in about ten minutes what takes me an hour and a half - that's what I pay him for. Gives me more time for other things.

I don't have an FSM for 84-86 handy, so I'll have to guess. If it's Delco, there are two possibles...

There's a "Delcotron," which is distinguishable by the case halves being retained by four small, long bolts, and the regulator plug has two wires and attaches to two 1/4" spade lugs on the periphery of the case back. The two prongs are for the regulator. This can usually be cranked up to about 100-120A, with a good builder.

Then, there's the Delco "CS-series," in two sizes (we have the CS-120, for the 120mm Armature OD.) These are found in pretty much any late-model GM, save specialty rigs like Police/Taxi packages, minivans with a LOT of electrical stuff, and half of anything full-size. This can be identified with the regulator plug being a Weatherpack type (black body, small pins, greenish gaskets,) and the case halves being retained by three bolts rather than four. Parts to make CS units put out 140A are easy enough to get, and sometimes luck will give you more (the one in my 88 is a fluke - it gives me 180A rock steady.)

If you do not have either of these, it is also possible to get a "one-wire" or "self-exciting" alternator, as long as you can find the right size case with the right mounting tabs. This allows for literal one-wire hookup of the alternator, and the regulator reads output voltage directly and is excited by an internal circuit, rather than reading system voltage from a harness connection or (worse! I don't know why ChryCo did this...) depending upon a "driver" signal from the ECU. For late-model ChryCo vehicles with ECU voltage regulation, a one-wire unit is a common fix for failed voltage regulation circuits (and is usually quite a bit cheaper!)

The Delcos are probably the easiest alternators to rebuild - and certainly the easiest to field service. However, there are several solder connections that are best handled with a "tong-style" resistance welder rather than a pencil iron, and working down in the bottom of the case is something that takes a fair bit of confidence. Changing brushes, regulators, and diodes are fairly easy - once you've learned the trick of it and get a little practise in (I've lost track of how many I've done by now...)

5-90

Both the Delcotron and CS-series have been seen with V-belts and Multi-rib setups

 

[85xjwoody]

The alternator that I have right now is a rayloc from Napa. Don't know if that is the same style as the Delco or not. I will first try to find a good local shop to do this then go to the local junkyard and get a dead alternator for five bucks off of another jeep. Thanks again for the help 5-90. If I end up not going this way would that alternator that puts out 94 amps be a good deal for under $100.00? It comes with a lifetime guarantee.

Kim.

 

[5-90]

Delco SI (Old style):

Delco CS (New Style)

Motorola (Common on older Jeeps & AMC):

And, if it just ain't one of these, I'd need a picture (unless someone else here can tell us what's he's most likely to have...)

5-90

 

[85xjwoody]

The first delco picture is identical to mine. I still need to go to the local yard to get an old one though because the housing on mine where I had to redrill a new hole is looking weak so I will get one from a junkyard that doesn't work for a few bucks. I will be calling around in the next day or two to see about rebuilding one to 140 amps or so. Still might also look into that one available with 94 amps at Advance Auto Parts. See what the local shops say about the rebuild. Thanks everyone for your help.

Kim.

 

[85xjwoody]

I think I found what I am looking for for an alternator. I called around to a few shops and found a pretty good one. Gentleman said that he is always doing 180 amp alternators for kids with big stereos. The price is only $100.00 and he has a couple ready to go. One year warranty. Thing that gets me is that he said it is a one wire setup. No need to use my plug that usually goes into the voltage regulator. Just the one red wire that connects to the back of my alternator. Is this correct? Is this possible to run my entire vehicle off of that one wire without having any problems? Only thing that I have to do is change the pulley over to mine which is for a serpentine belt. Does this seem right or wrong? Would like some opinions on this before I go and pick it up. Thanks for the help.

Kim.