Alt switched on wire to coil +

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fcm42000

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Is this ok? i modified my harness for hei, fast efi, batt in trunk and denso alt.

The alt wasn't charging so i took it to be tested it was completely fried, i was wondering if i did it.
 
Not really sure what you are asking.
More detail would be good.
 
I have a denso alternator and it requires a always hot and a switched hot to operate the internals of it, I'm not talking about the charging heavy gauge wire
 
fcm42000 said:
I have a denso alternator and it requires a always hot and a switched hot to operate the internals of it, I'm not talking about the charging heavy gauge wire
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incorrect; what you have it wired up as and what it requires is two different things in this case; denso alternators get wired the same as a 2 wire Chrysler alternator (3 if you count the main postive). If you have it wired up with two positives and the main heavy gauge positive its not correct. if you have it wired up any other way your sure to burn the alternator and other electronics out fairly quick

all alternators from the two wire Chrysler ones up to modern ones use the same wiring setup; only difference is modern ones are controlled by the ECU/PCM instead of a stand alone voltage regulator

they require a 12-14 gauge switched positive; a field wire coming from the regulator (as well as a switched positive to regulator) and a main heavy charging 6 or bigger gauge positive
 
66plyValiant said:
incorrect;
Click to expand...

My understanding is that some Denso's are isolated field/ external regulator

Some are integral regulator

We need to find out what the OP HAS. If this alternator came off a Mopar/ Jeep it must have an external regulator---original was internal to the computer

In this case, being converted to HEI, sounds like his coil+ is essentially "switched ignition run" or IGN2, which could be used to feed
 
67Dart273 said:
My understanding is that some Denso's are isolated field/ external regulator

Some are integral regulator

We need to find out what the OP HAS. If this alternator came off a Mopar/ Jeep it must have an external regulator---original was internal to the computer

In this case, being converted to HEI, sounds like his coil+ is essentially "switched ignition run" or IGN2, which could be used to feed
Click to expand...

the OP likely has a denso 120 model off a early ram (1988-1991) I would assume this because of the V belt. coil postive will work fine as that is appoximately where the original would get power (splice by oil pressure sensor and back of distributor) the only thing is you have to remember to send switched power to the firewall mounted regulator as well; in return it provides the field (usually green wire)

as far as intergral regulator I know of absolutly no chrysler products new or old that do that; they either have a external regulator on the firewall or the PCM/ECU controls the alternator output
 
66plyValiant said:
as far as intergral regulator I know of absolutly no chrysler products new or old that do that; they either have a external regulator on the firewall or the PCM/ECU controls the alternator output
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Exactly. But I don't know that he got this off a Mopar, hence my comments. Denso does make some internal regulated alternators for other applications. I'm not familiar enough to name/ or disregard the 'list'
 
66plyValiant said:
incorrect; what you have it wired up as and what it requires is two different things in this case; denso alternators get wired the same as a 2 wire Chrysler alternator (3 if you count the main postive). If you have it wired up with two positives and the main heavy gauge positive its not correct. if you have it wired up any other way your sure to burn the alternator and other electronics out fairly quick

all alternators from the two wire Chrysler ones up to modern ones use the same wiring setup; only difference is modern ones are controlled by the ECU/PCM instead of a stand alone voltage regulator

they require a 12-14 gauge switched positive; a field wire coming from the regulator (as well as a switched positive to regulator) and a main heavy charging 6 or bigger gauge positive
Click to expand...

are you saying i need to add an external regulator to it?
 
fcm42000 said:
are you saying i need to add an external regulator to it?
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if its toyota it could very well be internally regulated; I thought it was mopar denso; best to post a picture or a simluar picture if you can find one on google
 
If the alt is from a Toyota and has a round connector on the back with three terminals then it's internally regulated. Wire it according to the diagram. As an added note, a late '80s Toyota truck alt can easily be adapted to a Mopar and comes with a V belt pulley.
 

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What do you mean "sense?" "ignition?" I'm sure that needs to be switched ignition
 
The one labeled s on the schematic above, it senses voltage

Btw, just had the second alt tested and it failed every test, next time I will test it before I leave the parts store. I have a feeling I am doing something wrong
 
So what are the chances of getting two bad alternators in a row, they put both of them on the machine and they failed
 
Sounds like you wired it correctly. My only thought is insuring you have a good ground from the case of the alternator to the engine block (and from block to BATT-). The full alternator return current takes that path. It appears that the Vreg in the alternator is also connected to the case for a gnd reference. See if the alternator has a gnd stud. If so, run a thick wire from there to the block.

I once put a new Mopar alternator on my 69 Dart and still no charging, until I jumpered the case to block w/ jumper cables. Found my old alternator was good too. Aluminum easily gets corrosion where it doesn't conduct well.
 
fcm42000 said:
Sir I am counting on you
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Problem is I'm not familiar with "all of these" meaning the array of import "stuff."

LOOKS like you have it wired correctly. Only other suggestion is to have the parts joint test them before they leave the store.
 
67Dart273 said:
Problem is I'm not familiar with "all of these" meaning the array of import "stuff."

LOOKS like you have it wired correctly. Only other suggestion is to have the parts joint test them before they leave the store.
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Well senior looks like your right, the instructions i googled when i wired it had the ign sw on and lamp backerds so i was frying the regulator. you have to be careful of the schematic is it showing the plug or the alternator, they are mirrored.

i swapped the two wires and i am idling at 13.8v with the fan on.

Something funny, i was looking at a post where me and you had a pissing contest like 2 years ago. Thanks for the help, we appreciate it!!!
 
fcm42000 said:
i was looking at a post where me and you had a pissing contest like 2 years ago. Thanks for the help, we appreciate it!!!
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Many people argue with 67Dart273. Problem for them is he is almost always right, and he fesses up the few times he isn't.
 
BillGrissom said:
he fesses up the few times he isn't.
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'n I HATE doin' that LOL There's lots of things I'm having more trouble keeping up with in this line. Some of it has to do with REALLY poor documentation on the part of the parts outfits.
 
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