Replacement alternator options

[DeLorean]

What's a direct fit for the Ducy? I don't mind an alternator with a similar capacity that I can get for real cheap, like the early Saturn alternator for example. Anyone using one of those?

So far the Ducy is still working just fine, but everyone tells me I should have an alternator & tools to change it IN my trunk for WHEN the Ducy fails. At idle, with the fans running it's making around 11.5V, when rolling down the road, it's still reading 13.5, fans AC and lights on.

[content22207]

I've been running an Autozone unit for many years now. It was spec'd for a Volvo of some ilk (can't remember exactly which one -- I went by mounting ears in the right locations, and studs on the back rather than plug receptacles). 100 amp rated IIRC.

Bill Robertson
#5939

[TTait]

I'd say the DMCH unit is worth the money, but that said, you can get a cadillac alternator #7157112

It will require a Universal J bracket, which then needs modification, and a longer belt. You may need a spacer for one of the bolt holes and will have to transfer the fan and pulley off your ducey.

It works, and its cheap, but its not made for such high rpms I think - so it whines. First one lasted 6 months, but they have a lifetime warranty. next one may do better, or not. The best thing about them is the low price and lifetime warranty - your call.

To modify the J bracket, drill an additional hole spaced like the others but closer to the curved part of the J. then cut the bracket shorter by cutting off most of the straight part through, or just inside, the factory hole closest to your new one. Then get a belt, I found that a 15515 works very well. The ducey may have a spacer in it for the main bolt already, it not you need one with a 3/8" ID and a 1/2" OD - you can get spacers from the drawer at home depot, but you need to get two, as one goes inside the other to get the proper dims. Home depot spacers are too long so they then need to get cut down. You will need a couple 1/2" washers too.

To transfer the pulley and fan you will need an impact wrench, or have the parts store do it for you.

You may want to also get a GM plug, or you can work up a connector yourself.

When you go to install you may find that you can remove the mounting bolt without removing the upper muffler bracket - if so thats cool - if you do have to remove that bracket, mark it and notch it out a hair so you can swap out in the future without touching it.

When you do the work make sure you disconnect the battery first.

A floor jack is helpful in tensioning the alternator/belt.

If you do put in the caddy alternator it will give you good voltage even at idle if you use the smaller pully (the oem one may or may not be ok - not sure), but it will whine audibly above 3000 rpms.


Finally - whatever unit you put in - check your battery bulb in the dash before you start. It should illuminate when you first turn the key to run. I assumed my bulb was good because my ducey charged fine - but it was burned out. The ducey does not necessarily require this bulb to do its job. but your new alternator will. This bulb cannot be an LED - it must be incandescent.

The caddy is fine if:

Convenience in getting replacements is a major consideration,

you want a lifetime warranty,

You don't have a lot to spend, and

you don't mind replacing it if it fails.


But its not as good as one from the vendors. Between both cars I've run a Ducey, a motorola, Johns D140, a Houston 110, and the caddy. I don't have a lot of miles on it but I vote the best overall is the Houston 110. I'm told they are now getting units sourced from the chicagoland area, these are reportedly very good units. I note that Byrne also has a unit, but I have not tried it.

If I'd had not had both a cash crunch, and a lifetime warranty on the caddy, that's what I would have done last week.

Pics available if needed.

Tom

[DeLorean]

Thanks for the info Tom, I will keep this all in mind.