electrical problem please help or point in right dir

[kkempoo]

1993 240 sx with sr 20det swap just finished a cam upgrade and head resurfaced and noticed the battery had drained and the warning lights dash stays on. Installed new battery and it started right up and ran great for a day and then started to die when brake was pressed and dash lights would dim. It had an old viper alarm system in it and i thought that might have been causing problem and removed it. The car started right up and has 13.4 volts when running and 12.84when ignition is off. Runs but when u let off emergency brake or depress brake dash acc all dim and temp gauge will max out let off brake and put on e brake and gauge goes back to normal. Switched out tcu with buddies and relays could it be ign switch or something simple checked grounds theres got to be another 240 thats run into this problem please help


Modified by kkempoo at 11:43 AM 6/11/2009

[nissangirl74]

Would you call your girlfriend and ask her if you can borrow her period?

Kaithnxbai!

[AZhitman]

Oh yeah.... we're gonna need some punctuation.

Good info, but needs some organization.

<calls for electrical expert backup>

[SteveTheTech]

I have very little experience with swaps, but some general checks might work.

First check the connection at the alternator, also tension on the drive belt, a load test would also be a good idea as well as reserve capacity of your battery. Also make sure that you have <1ohm resistance in the negative battery lead (with the cable disconnected from the battery). If all of this checks you may have missed a ground somewhere on the engine, you can check this by performing a resistance verification test from the disconnected negative battery cable to a clean place on the cylinder head.

Good Luck, and I know from past experiences how frustrating that can be.

[kkempoo]

Thanks checked grounds they are ok. i'm going to swap out ign switch if that isn't it then. I'll start with all the wiring to brake and e brake there has to be a common wire they both use thats causing the problem. Pressing the brake and letting off e brake cause temp gauge to max out other than that its running great. But u can't run around with a temp thats faulty unless u like replacing motors. when i find out i'll put it up so if some else runs into it they know what to look for.

[SteveTheTech]

That is pretty interesting, if the temp gauge maxes out in conjunction with this issue I would be looking toward the power supply and ground at or near the gauges and their related circuits. This would be a fun one to play with in person although via internet is a crap shoot.

Have you tried the 240 tech forum. zeroforum/17

There are many members there that have been there and done that before and if anyone were going to be able to help you out it will be some of the members there. Please keep me updated I find electrical issues like this fascinating.

[kkempoo]

Its my friends car and got it driving except for the temp gauge problem. Here is the update so far i figured i'd check the temp senor and it has .5 volts going to it when the ign is off and 12.1 when running. As soon as u turn on wipers hit the brake or e brake it sends 12.6 volts to sending unit. Which i was thinking if the voltage is higher to sending unit that would make the gauge read higher. On the sr harness this is a blue wire with black stripe when you go inside it goes back to the ka harness. I hate electrical problems but they are a fact of on a 16 yr old car unless u install new harness. if i cant figure it out does anyone know a good shop in central fl. area that can help