Demons in my Charging System

[evolution157]

Demons, well not entirely, but there is certainly something the matter with it. my 74 manta isn’t charging. I removed the generator and took it in, it tested in the range it is suppose to. So then I figured that the regulator got fried at some point. I got a new one. It didn’t work. I’m thinking it must be a short somewhere. I don’t know what to do. Any recommendations?

--ryan

[namba209]

Originally Posted by evolution157 Demons, well not entirely, but there is certainly something the matter with it. my 74 manta isn’t charging. I removed the generator and took it in, it tested in the range it is suppose to. So then I figured that the regulator got fried at some point. I got a new one. It didn’t work. I’m thinking it must be a short somewhere. I don’t know what to do. Any recommendations? --ryan

IDK if you have a gage similar to the GT, but if you have an ammeter lite, battery lite, or alternator lite, check it out. If that lite is burned out, the charging system will not work.

[Lindsay]

1.Make sure GND wire between alternator & lower brkt bolt at engine block is installed/ clean. (no oil residue).
2. Check fusible link wire from alternator "'B" (output) to 10 GA RED wire.
3. Have battery checked; may not accept charge!

4. Opel FSM (factory service manual) instructions:
a. Shut off engine.
b. Fabricate short jumper wire with (2) male 1/4" terminals on each end.
c. Unplug regulator from alternator, install jumper between D+ / DF on regulator harness.
d. Start engine; charging indicator should peg in + position.
e. Shut-off engine and back to normal.

[nobody]

The 74 Manta and wagon didn't have a typical amp guage unless it had the rally guage set mounted just in front of the shifter under the dash. Otherwise it was idiot lights for amp and oil with no clock. There is also a second voltage regulator on the back of the standard guage set in the dash.

[Rionart]

Originally Posted by nobody There is also a second voltage regulator on the back of the standard guage set in the dash.

I always thought that voltage regulator was just to supply the fuel and temp gauges...

[evolution157]

Ok, my car doesn’t have an altimeter [or a clock, its pretty bare bones]. The charging light works for the most part. It gets brighter as the battery goes dead. Tonight I’m going to try to get a hold of some permatex dielectric grease and coat the some of the electric connections in the charging system. And of course clean up the connections on the generator. hopefully it works.

[nobody]

The second regulator powers the entire guage panel. The jumper method for the big regulator will show if the problem is in the charging system and is good to know. Another common problem area in that model is the fuse panel. They tend to corrode, especially since the area above it is prone to rust out and leak. HTH

[evolution157]

my fuse panel has seen better days, the battery box is completly rusted out above it, the number 3 fuse bracket is missing the bottom clip for the fuse. its really not to pretty. i took a second look at the area, and i have one large cylindrical fuse and two spots that look like they take the same sized plug. it says hella on it, so i assumed it was for the lights. any idea what it does, and do i need to put something into the other open ports?

[2 Fast 4 U]

Originally Posted by nobody There is also a second voltage regulator on the back of the standard guage set in the dash. Originally Posted by Rionart I always thought that voltage regulator was just to supply the fuel and temp gauges...

And you thought right

[evolution157]

Originally Posted by Lindsay 1.Make sure GND wire between alternator & lower brkt bolt at engine block is installed/ clean. (no oil residue). 2. Check fusible link wire from alternator "'B" (output) to 10 GA RED wire. 3. Have battery checked; may not accept charge! 4. Opel FSM (factory service manual) instructions: a. Shut off engine. b. Fabricate short jumper wire with (2) male 1/4" terminals on each end. c. Unplug regulator from alternator, install jumper between D+ / DF on regulator harness. d. Start engine; charging indicator should peg in + position. e. Shut-off engine and back to normal.

Ok so I tried the jumper, and I figured that if the thing is charging the light would go out. It did the opposite, hardcore, it lit up and then I think it burned out.

[Lindsay]

Car Clubs at Hemmings Motor News
There are three sets of wiring diagram for 74 Manta that may help. Hard to read in B&W.

If you take burn-out AMP Indicator bulb to VW (Volkswagen) parts store, they should have replacement. Interior bulbs are either #37 and #53.
http://www.opelgt.com/forums/1c-ligh...t-numbers.html

Does Manta use the very small #37 bulbs like GT?
Charging bulb on GT is #53; same on Manta?

[nobody]

Ok, you mentioned missing fuses. From right to left the values are 5, 5, 8, 15, 15 and 5. The last 5 amp fuse is tied into the bulb that went south and your charging system. If your key switch and headlights work then that will eliminate the fusable link. I think the missing fuses are the problem. I just had to find the right year FSM to be sure.

As for bulbs they aren't like in a GT at all. However in a pinch you can use one of the bulbs that light up the guage panel for the charging light in a Manta or wagon. They are the same but the other indicator lights are different. HTH