BJ40 with 13B-T and 12V Conversion

[LLoyer]

I recently picked up a 78 BJ40 with a 13B-T out of a 88 or 89 BJ74. It has a 12V conversion done and the ammeter has started to bounce when I switch on the turn signal. It is significantly worse when I signal a right turn. Last night I had headlights, no tail lights and no marker/turn signal lights. The truly odd thing is that if I dont have the headlights on then the turn signals/marker lights work but the ammeter just bounces. Does this sound like a ground problem or a alternator problem ? Looking for some advice. I put a meter on the battery while running and its charging at 12.93V.
Thanks.

 

[duncanrm]

I recently picked up a 78 BJ40 with a 13B-T out of a 88 or 89 BJ74. It has a 12V conversion done and the ammeter has started to bounce when I switch on the turn signal. It is significantly worse when I signal a right turn. Last night I had headlights, no tail lights and no marker/turn signal lights. The truly odd thing is that if I dont have the headlights on then the turn signals/marker lights work but the ammeter just bounces. Does this sound like a ground problem or a alternator problem ? Looking for some advice. I put a meter on the battery while running and its charging at 12.93V.
Thanks.

The factory ammeters are nearly useless .. you will get so much value out of a digital volt gauge. 12.93v charge may be ok if the battery is in a deep state of discharge but its low if the battery is charged.

 

[ceylonfj40nut]

Usually a ground problem for issues you are having with lights.

 

[LLoyer]

Usually a ground problem for issues you are having with lights.

That is my thought as well. Do you think I should start with a new ground cable for the battery and go from there? I imagine its going to be hard to track that ground fault down between the 13B-T swap and the 12V conversion.

 

[LLoyer]

The factory ammeters are nearly useless .. you will get so much value out of a digital volt gauge. 12.93v charge may be ok if the battery is in a deep state of discharge but its low if the battery is charged.

Fair enough, I am not really a big fan of the factory gauge cluster in general. Its useable but I would prefer more accurate numbers. As soon as I can get whatever ground issue this is sorted I think I am going to install a few digital gauges.

 

[LLoyer]

The factory ammeters are nearly useless .. you will get so much value out of a digital volt gauge. 12.93v charge may be ok if the battery is in a deep state of discharge but its low if the battery is charged.

The kicker is that it starts immediately on the first turn of the key. I really think theres a shoddy ground somewhere.

 

[Chamba]

Fair enough, I am not really a big fan of the factory gauge cluster in general. Its useable but I would prefer more accurate numbers. As soon as I can get whatever ground issue this is sorted I think I am going to install a few digital gauges.

I'm a fan of the Dakota Digital myself. I'm confident they've got a work-around to get the tach to work with your 13BT (best 4 cyl engine toyota had ever made, in my opinion).

However, without pics it'll be hard to motivate many here to reply......

 

[ceylonfj40nut]

That is my thought as well. Do you think I should start with a new ground cable for the battery and go from there? I imagine its going to be hard to track that ground fault down between the 13B-T swap and the 12V conversion.

Clean all your grounds. Start at demand points and work your way back to the battery. Make sure fuse panel has no corrosion. Remove fuses, wire brush. Light bulb sockets build corrosion, clean them. Make sure bulbs are working are working as wel